USGS Global Visualization Viewer: Help

Contents:

• USGS Global Visualization Viewer: Site Description
• USGS Global Visualization Viewer: Home Page
  • Latitude and Longitude
  • Sensor
  • View Images
  • Locator Map
  • What's New!
  • Quick Start Guide
  • Browser Requirements
  • Help
  • About Browse Images
  • Download Source Code
• USGS Global Visualization Viewer: Browse Image Viewer
  • Menu Bar
    • Collection Menu
    • Resolution Menu
    • Map Layers Menu
    • Tools Menu
    • File Menu
    • Help Menu
  • Navigation Controls
    • Locator Map
    • WRS Path/Row or Horizontal/ Vertical Tiles
    • Lat/Long
    • Max Cloud
    • Arrow Buttons
    • Scene Information
    • Date Selection
    • Scene List
  • Image Display Area
    • Keyboard Interface
    • Mouse Interface
    • Latitude and Longitude Display
    • Cooperator Logo
  • Tools Menu Options
    • Hidden Scene List
    • Scene List
    • Search For Scene
    • Search Limits
    • Swath Mode
    • User Defined Area
  • File Menu Options
    • Save and Load Scene Lists
    • Download Visible Browse & Metadata
    • Download Path & Row Browse & Metadata
• Frequently Asked Questions (FAQs)
  • Where is the geographic location displayed?
  • Why such long response times?
  • Why do some images appear to be tilted sideways?
  • Why do the scenes sometimes look misaligned in the mosaic view?
  • Why do some scenes appear to be "missing"?
  • Why doesn't the URL update when navigating, and why can't I save a bookmark that shows the viewer window that was last displayed when the bookmark was created?
  • Why does the "BACK" button take me all the way back to the home page, rather than to the browse image I was viewing last?
  • How can I print or save a browse image?
  • What if I want to purchase precision- or terrain-corrected Landsat data?
  • Why do latitude and longitude grid lines sometimes appear in the water map layer?
  • Why are the Latitude, Longitude, and Select Sensor selection boxes on the Home page not displaying or fully displayed on the page?
  • Why does the Shopping Basket, Metadata, or Browse Image fail to appear when I click the 'Order', 'Submit', 'Show Metadata', or 'Show Browse' buttons?
  • Why do the dates for some of the MODIS images on GloVis not correspond with imagery for the same date provided through the MODIS Rapid Response System?
  • Q: Why do I get a page indicating I need a newer version of Java?
  • Q: If I update to a newer version of Java, will it erase my existing version of Java?
  • Q:How do I download Imagery?
• Contact Customer Services

Back to the USGS Global Visualization Viewer Home Page

---

USGS Global Visualization Viewer: Site Description

The USGS Global Visualization Viewer (GloVis) is a quick and easy online search and order tool for selected satellite data. The viewer allows user-friendly access to all available browse images from the Landsat 7 ETM+, Landsat 4/5 TM, Landsat 1-5 MSS, EO-1 ALI, EO-1 Hyperion, NAPP, NHAP, MRLC, and Tri-Decadal data sets, as well as Aster TIR, Aster VNIR and MODIS browse images from the DAAC inventory. Through a graphic map display, the user can select any area of interest and immediately view all available browse images within the USGS inventory for the specified location. From the browse image viewer page, the user may either navigate to view adjacent scene locations or select a new area of interest. GloVis also offers additional features such as cloud cover limits, date limits, user-specified map layer displays, scene list maintenance, and access to metadata. An ordering interface is available for Aerial, Landsat, EO-1, ASTER and MODIS data purchases. Future GloVis releases will include the addition of data from other datasets within the USGS EROS archives.

Back to the Table of Contents

---

USGS Global Visualization Viewer: Home Page

Latitude and Longitude

The Latitude and Longitude form elements serve a dual purpose. Entering a latitude and longitude using the keyboard and clicking the View Images button will activate the Browse Image viewer window, which will display a mosaic of browse images centered on the selected location. The Latitude and Longitude form elements also display the latitude and longitude as the mouse cursor moves over the Locator Map.

Sensor

The USGS Global Visualization Viewer defaults to searching the Landsat TM archive. The other available datasets may be selected from within two dropdown lists.

View Images

Clicking the View Images button activates the Browse Image viewer window centered on the latitude and longitude entered in the Latitude and Longitude form elements. If no latitude and longitude values are entered, the Browse Image viewer window will center on a default location.

Locator Map

The global locator map of the world is displayed in the geographic projection, and includes limited cultural boundaries and shorelines. Clicking on any location within the locator map activates the Browse Image viewer window centered on the latitude and longitude selected.

What's New!

Describes all modifications and improvements included within the current release of the USGS Global Visualization Viewer.

Quick Start Guide

Provides a brief overview on using the USGS Global Visualization Viewer.

Browser Requirements

Provides a list of suggested browser and software requirements, and describes any known problems associated with particular browsers and/or operating systems.

Help (This page)

Provides general user information on controls, navigation, and functionality of the USGS Global Visualization Viewer.

About Browse Images

Provides information and Frequently Asked Questions (FAQs) regarding the USGS Global Visualization browse displays.

Download Source Code

Provides a link to a web site that allows downloading the source code used to produce the USGS Global Visualization Viewer web site. This code will only be of interest to people interested in creating similar web sites.

Back to the Table of Contents

---

USGS Global Visualization Viewer: Browse Image Viewer

The Browse Image Viewer page opens the Browse Image Viewer application in a separate window. Note that the web browser has to remain on the page to keep the application displayed.

The Browse Image Viewer application is implemented as a Java applet. It works with either the web browser's built in version of Java, or with the Java plug-in available from Sun. Note that some of the features are only available when using the Java plug-in from Sun (or a browser with an equivalent built-in version of Java). These features also require the user to answer "yes" to the security warning dialog that is displayed before the Browse Image Viewer application is shown. Answering "yes" to the security warning dialog grants the application the privileges required to access the user's local hard drive. The application uses this to do things like save the contents of the scene lists to the user's computer and reload them later at the user's request. Answering "Always" is the same as answering "yes", and will eliminate needing to answer the question on future visits to the web site.

The viewer application has four basic components: the menu bar, the controls on the left side of the main window, the browse images displayed on the right side, and the status bar.

The Browse Image Viewer application uses separate threads of execution for downloading data from the GloVis server. While data is being read from the server, various indicators are displayed in the image area of the display. The indicators describe what is being read, such as "Reading Inventory" to indicate the list of available scenes is being read, "Loading Imagery" to indicate browse images are being read, or "Loading Map Layers" to indicate map layers are being loaded. While images are loading, a coverage map is drawn in light blue to indicate where scenes are being loaded. The user can still interact with the applet while data is being read from the server, although some functions may be disabled temporarily.

Note: The viewer application window typically displays a line with a message "Java Applet Window". The location of this message varies depending on the Java implementation and Operating System being used.

Menu Bar

The Browse Image Viewer has a menu bar at the top of the application window to provide an interface to many of the options available in the viewer. The following paragraphs provide details on each of the available menu entries.

NOTE: On an Apple Macintosh, the menu bar selections are added to the menu at the top of the display instead of directly to the application window.

Collection Menu

The Collection menu allows the displayed dataset to be changed. The menu is organized into a cascading menu for each of the different types of dataset collections. The default dataset is set to the dataset selected on the home page.

NOTE: While the tool does allow the user to search multiple datasets, the scene list for each dataset is maintained separately. To order data from different datasets, you will need to order each list separately. The only exception to this is the L4-7 Combined scene list which shows the combined contents of the Landsat 7 ETM+, Landsat 7 ETM+ SLC-off, Landsat 4-5 TM, and Landsat 4-5 MSS scene lists. Ordering the L4-7 Combined scene list will order the scenes from all the related scene lists.

Resolution Menu

The Resolution menu allows the resolution displayed in the image display area to be changed. All resolutions of browse images (and selected map layers) are displayed in the Lambert Azimuthal Equal Area projection, except for MODIS data which is displayed in the Sinusoidal projection and NAPP/NHAP data which is displayed in the geographic projection. At the highest resolution, a single scene is shown.

The available resolutions are:

• EO-1 ALI, Landsat 7 ETM+, L7 ETM+ SLC-off, Landsat 4-5 TM, Landsat 1-5 MSS, L4-7 Combined, MRLC 2001 Radianc, MRLC 2001 Reflectance, Tri-Decadal ETM+, and PanSharp ETM+
  • 1000 meters in GIF format
  • 240 meters in JPEG format
• EO-1 Hyperion
  • 1000 meters in GIF format
  • 120 meters in JPEG format
• NALC Triplicates, Tri-Decadal TM, and Tri-Decadal 1-5 MSS
  • 1000 meters in GIF format
  • 480 meters in JPEG format
• ETM+ Pan Mosaics
  • 1000 meters in GIF format
  • 285 meters in JPEG format
• TM Mosaics
  • 2000 meters in GIF format
  • 700 meters in JPEG format
• ASTER
  • 1000 meters in GIF format
  • 400 meters in GIF format
  • 90 meters in JPEG format
• MODIS
  • 10000 meters in JPEG format
  • 5000 meters in JPEG format
• NAPP
  • Note that NAPP data is in the geographic projection, so pixel sizes are in degrees.
  • low (0.00045 degrees) in JPEG format
  • high (0.00015 degrees) in JPEG format
• NHAP
  • Note that NHAP data is in the geographic projection, so pixel sizes are in degrees.
  • low (0.00090 degrees) in JPEG format
  • high (0.00030 degrees) in JPEG format

For band combinations and further details on the browse image, see About Browse Images.

Map Layers Menu

The Map Layers menu allows the displayed map layers to be selected. The map layers available include administration boundaries, the current collection grid representation, country boundaries, a north arrow, a user defined point of interest, protected area points, protected area polygons, railroads, roads, an overlay of the scenes in the scene lists, water (rivers and shorelines), and world cities. The overlay of the scenes in the scene lists is enabled by default.

NOTE: Due to reprojection issues, the map layers shown in the display may be slightly inaccurate relative to the satellite browse image. The map layer display should only be used as a general guide.

NOTE: The administration boundaries, protected area points, protected area polygons, railroads, and roads map layers are not available for MODIS data.

The option to load shapefiles from the user's local computer is also available if the applet was granted sufficient privileges by answering "Yes" to the security warning when the applet loaded.

The options in the Map Layers menu include the following. Note that the colors mentioned for the map layers are the default colors. In most cases the colors can be modified using the Modify Colors Dialog.

• All Map Layers: An overlay of all the map layers that are available for the current dataset is added to the current browse image display. Note: The example image does not include the north arrow.

  

• Address Search Result: An icon indicating the last displayed location from the Search for Address option is shown in the image display area. The address search result is shown as an yellow "stick-pin".

  

• Admin boundaries: An overlay of administration boundaries is added to the current browse image display. The administration boundaries are white in color. The administration boundaries layer includes country, state, and other large-scale cultural boundaries.

  

• Cities: An overlay of major world cities is added to the current browse image display. Both the city location and name are yellow. Capital cities are indicated by a star icon and other cities are indicated by a yellow dot. Smaller cities will be shown at higher resolutions.

  

• Collection Grid: An overlay of the WRS-2 or WRS-1 scene centers (displayed as yellow squares), the MODIS grid tile outlines (displayed as a yellow outline around the image), or the UTM grid centers for the Mosaic datasets (displayed as yellow squares) are added to the current browse image display.

     

• Country boundaries: An overlay of country boundaries is added to the current browse image display. The country boundaries are white in color. The country boundaries layer is a subset of the admin boundaries layer that includes only the country boundaries. Note that the country boundaries are drawn using wider lines than the admin boundaries.

  

• North Arrow: An overlay of an arrow pointing north is added to the upper left corner of the current browse image display. The arrow is white in color with a black outline. The arrow rotates in the direction of north when moving to different locations. This is provided since the projection used to display the browse images preserves pixel area while distorting direction.

  

• Point Of Interest: An overlay of a users selected point of interest is added to the current browse image display. The point of interest feature resembles an orange "stick-pin".

  

• Protected Area Points: An overlay of protected areas is added to the current browse image display. The protected areas are displayed as yellow dots. When the mouse cursor is over a point, the name of the protected area is displayed in the applet status bar after the lat/long display. The Protected Area Polygons and Points datasets sometimes contain different areas.

  NOTE: The protected area information displayed by GloVis was obtained from the World Database of Protected Areas (WDPA) Consortium, December 2007 version. The World Database on Protected Areas (WDPA) is a joint venture of UNEP and the IUCN, produced by UNEP-World Conservation Monitoring Centre (UNEP-WCMC) and the IUCN WCPA working with governments and collaborating NGOs. The WDPA is updated continuously providing the most current data on protected areas worldwide. Please go to www.unep-wcmc.org/wdpa for more information. UNEP-WCMC bears no responsibility for the integrity or accuracy of the data contained herein.

  GloVis processes the original data to the projection being displayed and reformats it into files that are easier to use with the applet.

  

• Protected Area Polygons: An overlay of protected areas is added to the current browse image display. The protected areas are displayed as polygons and are displayed in yellow. When the mouse cursor is over a polygon, the name of the protected area is displayed in the applet status bar after the lat/long display.

  NOTE: The protected area information displayed by GloVis is obtained from the World Database of Protected Areas (WDPA) Consortium, December 2007 version. The World Database on Protected Areas (WDPA) is a joint venture of UNEP and the IUCN, produced by UNEP-World Conservation Monitoring Centre (UNEP-WCMC) and the IUCN WCPA working with governments and collaborating NGOs. The WDPA is updated continuously providing the most current data on protected areas worldwide. Please go to www.unep-wcmc.org/wdpa for more information. UNEP-WCMC bears no responsibility for the integrity or accuracy of the data contained herein.

  GloVis processes the original data to the projection being displayed and reformats it into files that are easier to use with the applet.

  

• Railroads: An overlay of major railroads is added to the current browse image display. The railroads are dark pink in color.

  

• Roads: An overlay of major roads and thoroughfares is added to the current browse image display. The roads are tan in color.

  

• Scene List Overlay: An overlay of the scenes added to any of the scenes lists in the applet is added to the current browse image display. The scene list overlay is shown in green. The scene lists to include can be modified using the Configure Scene List Overlay Dialog box.

  

• Water: An overlay of major rivers and shorelines is added to the current browse image display. The water features are blue in color.

  

• No Map Layers: All previously selected map layers will be removed from the current browse image display.
  
• Modify Colors...: Opens a dialog box that allows the color used to display each of the standard map layers to be modified. To change a color for a map layer, click on the button associated with the map layer and select the color to use. The color change is not applied until the dialog's Ok or Apply buttons are pressed. The Default button returns all the map layers to their original colors (the Ok or Apply buttons need to be pressed to apply the change). The Cancel button will exit the dialog without applying any unapplied changes.
  
• Search for Address...: Opens the Search for Address Dialog Box which provides the ability to search for an address and display the location of the address in the image display area.

  The Search for Address Dialog Box provides the following:

  • Enter Address: The enter address text field allows entering an address. Pressing the enter key initiates the search. The address can be a city name, street address, zip code, or even a major landmark.
  • Address Search Results: After a search completes, the results are displayed in a list. The results provide the full matching address along with the latitude and longitude of the address. Double-clicking on one of the results displays the location in the image display area and marks it with an icon (only the last address selected is displayed).
  • Search: The search button initiates a search for the address in the enter address text field, just like pressing the enter key does in the enter address text field.
  • Display: The display button displays the currently selected result in the results list, just like double-clicking on the address in the list.
  • Clear: The clear button clears the address entry field and search results list.
  • Close: The close button closes the dialog box.
• Set Point Of Interest...: Opens the Point Of Interest Dialog Box which provides the ability to display a point in the image display area by entering a latitude and longitude.

  The Point of Interest Dialog Box has the following characteristics:

  • Latitude: The latitude entry box for entering a valid Latitude.
  • Longitude: The longitude entry box for entering a valid Longitude.
  • Set: The set button sets the Point of Interest
  • Clear:The clear button removes the previously set Point of Interest.
  • Close:The close button closes the dialog box.
• Configure Scene List Overlay...: Opens a dialog box that allows selecting which scene lists should be shown as part of the Scene List Overlay map layer. A checkbox for each dataset is provided. Buttons to set or clear all the checkboxes are provided. Any changes are applied by the Ok and Apply buttons, while the Cancel button will exit without applying any unapplied changes.
• Read Shapefile...: Displays a file open dialog box to allow choosing a shapefile to read. When a shapefile is chosen, the user is also allowed to choose the color used for displaying the shapes. Note that only shapefiles using geographic coordinates are supported and the shapefile should be referenced to the WGS84 or NAD83 datum for best results. When the shapefile is loaded, the image display area is centered at the center of the shapefile coverage if it is not already displaying an area covered the shapefile.
• Show Shapefile Attributes...: Opens a dialog box that displays the attributes for the last shapefile shape that has been clicked on. Each shapefile that is loaded also has a tab available in the dialog box that allows configuring the following:
  • The attributes to display when a shape from the file is clicked on.
  • The color to use when drawing the shapes from the file.
  • The attribute to display in the statusbar when the mouse is hovering over a shape from the file.
  • A simple interface that allows displaying a subset of the shapes in the file by choosing to display only the shapes that have a particular value for an attribute.
• Shapefiles: For each shapefile that is read, a menu option with a checkbox is added to the menu to allow turning the display of that shapefile on and off. When the shapefile display is turned on, the image display area is centered at the center of the shapefile coverage if it is not already displaying an area covered the shapefile.

Tools Menu

The Tools menu provides the following options:

• Default to Selected Date: When selected, changing the displayed active scene to a different date will change all the displayed scenes to the closest available date.
• Hide Scenes...: Opens the Hidden Scene List Dialog Box.
• NDVI Graph...: Opens the NDVI Graph Dialog Box for Landsat, EO1, MRLC, Tri-Decadal TM, Tri-Decadal ETM+ and Tri-Decadal Pansharp ETM+ only.
• Print...: Allows printing the current contents of the main applet window. It opens a dialog that allows setting the printing parameters and selecting the destination printer. The dialog displayed is specific to the operating system being used.
• Refresh: Refreshes the data displayed by reloading the scene inventory and browse images from the web server. This is useful to users who are waiting for the most recently acquired scenes to become available. This can also be done by using the "CTRL+R" keyboard shortcut on most browsers.
• Scene List...: Opens the Scene List Dialog Box.
• Search For Scene...: Opens the Search For Scene Dialog Box.
• Search Limits...: Opens the Search Limits Dialog Box.
• Swath Mode: Enables Swath Mode for Landsat and ASTER datasets only.
• Tool Tips: Enables tool tips in the GUI.
• User Defined Area...: Opens the User Defined Area Dialog Box for ASTER and EO-1 datasets only.

File Menu

The File menu provides options to save files to the user's hard drive and load data into the GloVis application from the user's hard drive. The File menu is only available when using the Java plug-in and the GloVis applet was granted sufficient privileges by the user answering "yes" to the security warning dialog that is displayed before the applet loads.

• Save All Scene Lists...: Saves the contents of all the dataset scene lists. See Save and Load Scene Lists.
• Load Saved Scene List...: Loads a previously saved scene lists file. See Save and Load Scene Lists.
• Save Hidden Scene Lists...: Saves the contents of all the hidden scene lists. See Save and Load Scene Lists.
• Load Hidden Scene List...: Loads a previously saved hidden scene lists file. See Save and Load Scene Lists.
• Download Visible Browse & Metadata...: Downloads the original browse image and metadata file for the scenes visible on the display. See Download Visible Browse & Metadata.
• Download Path path, Row row Browse & Metadata...: Downloads the original browse image and metadata file for the scenes in path path and row row that match the current search limits. See Download Browse & Metadata.
• Download Scene List Browse & Metadata...: Downloads the original browse image and metadata file for the scenes in the current scene list. See Download Scene List Browse & Metadata.

Help Menu

The Help menu provides selections for several different sources for help. The menu selections include:

• Quick Start Guide: Provides a link to the Quick Start Guide.
• Viewer Help: Provides a link to this page.
• About Browse Images: Provides a link to the About Browse Images web page.
• Product Information: Provides a link to a web page with additional information about the currently selected dataset.
• Data Acquisition Schedule: Provides a link to the acquisition schedule for the currently selected dataset. Note: Some datasets do not have an acquisition schedule web page available.
• Data Acquisition Request: Provides a link to a web page that allows submitting a request for a data acquisition. This is only available for the EO-1 datasets.
• Home: Provides a link to the USGS Global Visualization home page.

Navigation Controls

The left side of the application window has various naviation controls that are explained in the following paragraphs.

Locator Map

The locator map is the map of the world in the upper left corner of the applet window. It indicates the currently displayed location with a small diamond-shaped icon. A new display location can be selected by clicking on a location within the locator map. Scroll bars along the right and bottom edges of the locator map allow navigation to areas not currently in the viewing area. When the cursor passes over the locator map, the status bar of the applet window displays the latitude and longitude of the location under the cursor. The WRS path and row are also displayed (except for MODIS data where the H/V tile numbers are displayed, and the ETM+/TM mosaics where no path and row info is displayed).

There are three different images displayed for the locator map. The image used for most of the datasets is a smaller version of the map displayed on the GloVis home page. It is in the geographic projection.

For the MODIS datasets, a locator map in the sinusoidal projection is displayed for the locator map. Clicking in the gray area that is off the edge of the world will not change the displayed area in the image display area.

For the NAPP and NHAP datasets, a geographic projection map of only the lower 48 states is shown since the data is only available there.

WRS Path/Row or Horizontal/Vertical Tiles

For most datasets, the first and second fields display the second version of the World Reference System (WRS-2) path and row (or WRS-1 for Landsat 1-3 MSS data) of the active (highlighted) scene within the display.

For the MODIS datasets, the first and second fields display the horizontal and veritical tile number of the MODIS reference grid. The image display area can be moved to a new location by entering a new path/row (or tile number) and pressing the enter key or clicking the "Go" button. MODIS Tile numbers that fall outside the edges of the world are rejected.

For the ETM+ Mosaic, TM Mosaic, and NHAP datasets, this field is not available since there is no regular grid available.

For the NAPP dataset, the entry fields are the flight line and station.

Lat/Long

The first and second fields display the latitude and longitude of the center of the active (highlighted) scene within the display. The browser may be updated to a new location by entering new latitude and longitude coordinates and pressing the enter key or clicking the associated "Go" button.

Max Cloud

The cloud cover dropdown list allows the user to restrict the displayed browse images to only those that meet specific cloud cover restrictions. By default, the USGS Global Visualization tool will display all browse images in the archive (Max Cloud 100%). A maximum cloud restriction of 0% (Max Cloud 0%) will display only cloud-free images. The cloud cover restriction can be set in 10% increments.

Note: The cloud cover values for each scene are provided to GloVis by the data provider. They are typically estimates and may not accurately reflect the cloud cover actually present in the scene.
Note: The Max Cloud cover option is not available for some datasets.

Arrow Buttons

The arrow buttons allow spatial navigation from the selected scene to the next adjacent path and row (or tile). The up/down arrows will update the browse display to be centered over the next or previous row. The left/right arrows will update the browse display to be centered over the next or previous path (or horizontal tile).

When displaying ASTER data at the 400m resolution, the arrow buttons will step by 1/3 of a path or row.

Scene Information

The information displayed pertains to the active (highlighted) scene within the display and varies with the selected dataset. It can include:

• ID: the scene ID
• Cloud Cover: the estimated cloud cover
• Quality: image quality value ranging from 0-9
• Date: the acquisition date
• Pointing Status: for EO-1 data, an indication is provided on where the sensor was pointing (at nadir, within the path/row, or outside the path/row)
• Sensor: for the L4-7 Combined data, an indication is provided for the source sensor
• Roll: film roll number (for NAPP/NHAP data only)
• Frame: frame number on the roll of film (for NAPP/NHAP data only)
• Proj: project name that collected the scene (for NAPP/NHAP data only)

The information in the scene information area can be copied to the clipboard for pasting to other applications. The method to copy information to the clipboard varies depending on the browser and Operating System used. For Internet Explorer on Windows, highlight the information to copy using the mouse and copy it by pressing "CTRL-C". For Netscape Navigator on Windows, highlight the information to copy using the mouse, click the right mouse button, and select "copy". Other browsers and Operating Systems may require other methods to be used.

Date Selection

This area allows the user to navigate through all available acquisition dates, which also meet any user-specified Search Limits. Note that the dates available in the month and year dropdown lists reflect the year and month ranges set in the Search Limits. For Landsat and MODIS data, the date navigation applies to the currently selected path/row or tile. For ASTER and EO-1 data, the date navigation applies to all the currently displayed scenes or scenes that cross the User Defined Area.

Note that this field may not be present for some datasets.

• Landsat and MODIS Date Navigation
  • The date navigation applies to the active (highlighted) path and row or horizontal and vertical tile.
  • Go: will display the user-specified month and year
  • Prev Scene: will display the previous acquisition date
  • Next Scene: will display the next acquisition date
• ASTER and EO-1 Date Navigation
  • The date navigation applies to all currently visible scenes or to scenes that intersect the User Defined Area. Since ASTER and EO-1 data are not aligned to WRS path and rows, scene navigation is based on satellite swaths.
  • Go: will make the first displayed scene matching the user-specified month and year the active scene
  • Prev Scene: will make the previous scene in the current swath the active scene or if at the beginning of a swath it moves to the end of the previous swath
  • Next Scene: will make the next scene in the current swath the active scene or if at the end of a swath it moves to the start of the next swath

Double left-clicking on a scene in the browse image display will perform the same function as selecting the "Next Scene" button (The first click will select the scene below the cursor, making this not very useful for ASTER data).

NOTE: A date selection button will be disabled if the active scene is the first or last available scene and no previous or next scene exists in the inventory (according to any user-specified limits set in the Search Limits Dialog Box).

Scene List

The scene list allows the user to maintain a list of selected scenes for each dataset. The list includes the scene ID for each scene selected. The user can add, delete, order (where available), submit (where available), or download (where available) the contents of the currently displayed list. The vertical scroll bar along the right margin of the list allows the user to navigate up and down within the list. The tooltip shown when the mouse cursor hovers over the scene list indicates how many scenes are in the list.
Note: There is a maximum URL length that limits the number of scenes that can be passed to a shopping basket. If this limit is reached, pressing the order or submit button only submits as many scenes to the shopping basket as the URL limit allows and a message box is displayed warning the user this has happened. The rest can be added by pressing the order or submit button again (as many times as it takes).

• Add: The currently active (highlighted) scene within the browse viewer window is added to the scene list.
• Delete: The selected scene within the scene list is deleted from the list. A scene is selected by clicking on the scene ID with the mouse.
• Order (where available): Places all scenes within the current scene list for the selected dataset only, up to the limit imposed by the maximum URL length, into the user's Shopping Basket.
• Submit (where available): Places all scenes within the current scene list for the selected dataset only, up to the limit imposed by the maximum URL length, into the user's Shopping Basket.
• Download (where available): For the selected dataset,
• Download (where available): For the selected dataset, the highlighted scene within the current scene list will be downloaded at no charge.
• Right-clicking: Right-clicking on the scene list displays a popup menu for the selected scene in the list. The menu allows the following actions:
  • Scene Information: A summary of selected scene ID, cloud cover (when available), and acquisition date. A quality value will be included for Landsat data only.
    NOTE: selecting the scene information in the menu does not result in any action being taken.
  • Show Metadata: A detailed set of metadata is displayed in a new browser window. FGDC metadata is available via a link at the bottom of the metadata display for the Landsat and EO-1 datasets.
  • Show Browse: The original full-resolution browse image is displayed in a new browser window.
  • Display: The scene is displayed as the active (highlighted) scene in the image area display. The viewing location is repositioned if needed.
    NOTE: The display option will be disabled if the selected scene in the list does not meet the current search limits.
    NOTE: double-clicking with the left mouse button on a scene in the scene list will also display the scene.
  • Delete: The scene is deleted from the list.
  • Order (where available): Places all scenes within the current scene list for the selected dataset only, up to the limit imposed by the maximum URL length, into the user's Shopping Basket.
  • Submit (where available): Places all scenes within the current scene list for the selected dataset only, up to the limit imposed by the maximum URL length, into the user's Shopping Basket.
  • Download (where available): For the selected dataset, the highlighted scene within the current scene list, will be downloaded at no charge.
  • Restore: Restores the list of scenes to the Scene List after placing an order. This is to be used when an order failed to be entered. (This option has to be used immediately after placing an order. Once another scene is added to the scene list, the restore list is gone and the restore option will be unavailable.)
    NOTE: All Aerial, Landsat, EO-1, ASTER and MODIS datasets are entered into the USGS shopping basket. Duplicate entries can be entered into this shopping basket, so users are advised to review the entire order before submitting the order for processing.
  • More... : This option displays the scene list dialog box.

  NOTE: On an Apple Macintosh, right-clicking is performed by holding down the option button and clicking on the single mouse button.

IMPORTANT: The USGS Global Visualization Viewer will maintain a separate scene list for each dataset (except for the L4-7 Combined dataset which combines the scene lists for all the related datasets). Multiple datasets may be alternately searched and multiple lists may be created. However, each scene list must be individually ordered. After a scene list has been ordered, that scene list will be emptied of all previous contents.

Note: All Aerial, Landsat, EO-1, ASTER and MODIS datasets are entered into the USGS shopping basket. When ordering multiple scene lists, the scenes ordered will be combined to populate a single order in the Shopping Basket.

Image Display Area

The right side of the application window displays browse images and map layers for the currently selected dataset and viewing area. The following paragraphs provide some details on the image display area.

Keyboard Interface

If the mouse cursor is clicked in the browse image area, a keyboard interface is available for selecting scenes. The following keys are available:

• Arrow Keys: The keyboard arrow keys will move the center of the display a single path or row (or tile) in the direction of the arrow pressed (or 1/3 of a path or row for ASTER data at 400m), just like the arrow buttons.
• Page Up: The page up key will display the previous acquisition date, just like the "Prev Scene" button.
• Page Down: The page down key will display the next acquisition date, just like the "Next Scene" button.
• Home: The home key will display the first available acquisition date.
• End: The end key will display the last available acquisition date.

NOTE: As with the display buttons, the keyboard interface will be limited to any user-specified search limits.

Mouse Interface

The mouse buttons have the following functions in the browse image area (except when the User Defined Area dialog box is open. For the mouse interface in this case, see the User Defined Area documentation.)

• Left-clicking: Left-clicking on a scene makes that scene the active scene and places it on top of any other images on the display.
• Left-click, hold + drag: Pressing and holding the left mouse button in the browse image area and dragging the mouse will adjust the area being displayed. Releasing the mouse button will automatically load the scenes to display for that area. This can be used to navigate without using the arrow buttons. It is also useful when viewing areas with scrollbars (like Landsat 7 ETM+ at 240 meters sometimes shows). If being used to navigate to new areas, it may be helpful to turn on the political boundary map layer.
• Double Left-clicking: Double left-clicking on a scene updates the scene to the next acquisition date like the Next Scene button and displays the scene selected (highlighted) in the image display area.
  NOTE: This option only allows the image to move to the next available scene and not back to the previous scene.
• Alt/Shift/CTRL Left-clicking: Holding down the Alt, Shift, or CTRL key (depending on the operating system) when left-clicking on a scene moves that scene behind all the other visible scenes. If the scene was the active scene, the new top scene is made the active scene.
• Right-clicking: Right-clicking on a scene in the browse image area will display a pop-up menu for the scene. The menu displays the following:
  • Scene Information: Summary of selected scene ID, cloud cover, and acquisition date. Quality value will be included for Landsat data only.
    NOTE: No action occurs when scene information is selected.
  • Show Metadata: A detailed set of metadata for the scene is displayed in a new browser window. FGDC metadata is available via a link at the bottom of the metadata display for the Landsat and EO-1 datasets.
  • Show Browse: The original full-resolution browse image for the scene on is displayed in a new browser window.
  • Add to Scene List: The scene on is added to the scene list.
  • Add All to Scene List: All currently visible scenes are added to the scene list.
    NOTE: This option is not available for ASTER or EO-1 data.
  • Add User Area Scenes: All scenes currently in the user-defined area will be added to the scene list.
    Note: This option is only available when the User-defined Area is enabled.
  • Remove From Scene List: The scene is removed from the scene list. This option will be disabled if the scene is not in the scene list.
  • Hide Scene: The scene is added to the hidden scene list and the scene is removed from the image display area.
  • Bring to Front: The scene is placed in front of all other scenes in the area.
  • Send to Back: The scene is placed behind all other scenes in the area.
  • Previous Avail. Date: The scene is changed to the previous available date. This option will be disabled if there are no previous scenes available.
    NOTE: This option is not available for ASTER or EO-1 data.
  • Next Avail. Date: The scene is changed to the next available date. This option will be disabled if there are no scenes after the displayed scene.
    NOTE: This option is not available for ASTER or EO-1 data.
  • Set Point Of Interest: Sets a point of interest where the cursor is on the display, enabling the point of interest map layer. The point selected latitude and longitude values are added to the Point of Interest dialog box.
    
  • Set Scenes To Date: The Date shown in the menu is the acquisition date of the scene selected. All the displayed scenes are set to the acquisition date that is nearest to the shown Date (subject to any search limits that are currently applied). This provides a quick way to set all the displayed scenes to roughly the same date.
    Note: This option is not available for ASTER or EO-1 data.
  • Default Scene: The scene is changed to the default scene
    

NOTE: For ASTER and EO-1 data, if the point clicked on intersects multiple scenes the right-click menu has a submenu on it to select between the scenes. The selected one is made the active scene.

NOTE: On an Apple Macintosh, right-clicking is performed by holding down the option button and clicking on the single mouse button.

Latitude and Longitude Display

When the cursor is over the browse image display or the locator map, the status bar of the browser displays the latitude and longitude under the cursor. The values are reported as decimal degrees.

Cooperator Logo

For each data set, a logo for the cooperator who made the data available is displayed in the lower left or lower right corner of the browse image area. Clicking on the logo will open a new browser window to the cooperator's web site.

Status Bar

The bottom of the Browse Image Viewer application window displays a status bar for the application. The status bar is separated into three areas. Those three areas provide the following information (from left to right):

• The resolution being displayed
• The search limits in effect (date, scene list, quality, user defined area, and/or data version)
• The latitude and longitude of the location under the mouse cursor, and WRS path and row (or tile number, or flight line and station) if the mouse cursor is over the locator map. If a protected areas map layer is displayed and the mouse cursor is over an area, the protected area name is displayed. If a user shapefile is displayed, information may be displayed for the shape the mouse cursor is over.

Tools Menu Options

The Browse Image Viewer provides several tools under the Tools Menu that allow interacting with the application. Most of the options open a dialog box. The options are described in the following paragraphs.

Hidden Scene List

The Hidden Scene List dialog box provides the capability of hiding and unhiding scenes in the image display area. This functionality is useful if a user wants to only view certain images in the viewer window. The user can then pick what scenes they want hidden or unhidden. The tooltip shown when the mouse cursor hovers over the scene list indicates how many scenes are in the list.

The Hidden Scene List dialog has the following characteristics:

• Scene List Name: The name of the current hidden scene list appears at the top of the dialog box.
• Scene List: The list includes the scene ID, cloud cover percentage, and acquisition date for each scene in the list. A quality value will also be included for Landsat data. The vertical scroll bar along the right margin of the list allows the user to navigate up and down within the list.
• Hide Button: The currently active (highlighted) scene within the Image display area is added to the hidden scene list and the image is removed from the image display area.
• Unhide Button: The selected scene within the hidden scene list is deleted from the list and the image is added to the image display area.
• Close Button: Pressing the close button closes the dialog box.

NDVI Graph Dialog Box

The NDVI Graph dialog box provides the capability of displaying Normalized difference Vegetation Index (NDVI) data on a Line graph for the selected WRS-2 path and row in the image display area.

• Line Graph tab:
  • Line Graph: The line graph displays the NDVI value for two week periods for the year of the currently selected scene. A black line will be drawn vertically at the date selected.
  • Clicking graph area: Clicking in the graph area will select the scene closest to the date clicked on.
  • Print Button: Pressing the print button allows the current contents of the line graph to be sent to a printer. A dialog is opened that allows setting the printing parameters and selecting the printer to use.
  • Close Button: Pressing the close button closes the dialog box
• Select Landcover:
  • Landcover Checkboxes: Allows the user to turn the landcovers on and off the landcovers that are displayed on the Line Graph tab.
  • Set Default Button: Selects the top five landcovers for the selected WRS-2 path and row in the display area.
  • Close Button: Pressing the close button closes the dialog box.

Scene List

The Scene List dialog box provides an expanded version of the scene list on the left side of the application window. The two scene lists contain the exact same list of scenes. The primary differences are that the list displays more information about each of the scenes in the list and there are more buttons available for interacting with the list (essentially duplicating the right-click menu available in the scene list on the left side of the application window). The tooltip shown when the mouse cursor hovers over the scene list indicates how many scenes are in the list.
Note: There is a maximum URL length that limits the number of scenes that can be passed to a shopping basket. If this limit is reached, pressing the order button only submits as many scenes to the shopping basket as the URL limit allows and a message box is displayed warning the user this has happened. The rest can be added by pressing the order button again (as many times as it takes).

The following are available in the Scene List dialog box:

• Scene List Name: The name of the current scene list appears at the top of the dialog box.
• Scene List: The list includes the scene ID, cloud cover percentage, and acquisition date for each scene in the list. A quality value will also be included for Landsat data. The vertical scroll bar along the right margin of the list allows the user to navigate up and down within the list.
• Add: The currently active (highlighted) scene within the browse viewer window is added to the scene list.
• Delete: The selected scene within the scene list is deleted from the list.
• Display: The scene selected within the scene list is displayed as the active (highlighted) scene in the image area display. The viewing location will be repositioned if needed.
  NOTE: The display option will be disabled if the selected scene in the list does not meet the current search limits.
  NOTE: double-clicking with the left mouse button on a scene in the scene list will also display the scene.
• Order (where available): Places all scenes within the current scene list for the selected dataset only, up to the limit imposed by the maximum URL length, into the user's Shopping Basket.
• Submit (where available): Places all scenes within the current scene list for the selected dataset only, up to the limit imposed by the maximum URL length, into the user's Shopping Basket.
• Download (where available): For the selected dataset, the highlighted scene within the current scene list, will be downloaded at no charge.
• Show Metadata: A detailed set of metadata for the scene selected within the scene list is displayed in a new browser window. FGDC metadata is available via a link at the bottom of the metadata display for the Landsat and EO-1 datasets.
• Show Browse: The original full-resolution browse image for the scene selected within the scene list is displayed in a new browser window.
  ASTER
  • 90 meter sub-sampled JPEG in a rotated UTM projection
  EO-1 ALI, Landsat 7 ETM+, L7 ETM+ SLC-off, MRLC 2001 Radiance, MRLC 2001 Reflectance, Tri-Decadal ETM+, and PanSharp ETM+
  • 240 meter sub-sampled JPEG in satellite (path) orientation
  EO-1 Hyperion
  • 120 meter sub-sampled JPEG in satellite (path) orientation
  Landsat 4-5 TM, Landsat 4-5 MSS
  • 480 meter or 240 meter sub-sampled JPEG in satellite (path) orientation
  Landsat 1-3 MSS
  • 480 meter or 240 meter sub-sampled JPEG in satellite (path) orientation for most dates, but in a north-up orientation for January 1979 - May 1981
  MODIS
  • 5000 meter sub-sampled JPEG in the sinusoidal projection
  NALC
  • 480 meter sub-sampled JPEG in satellite (path) orientation
  NAPP
  • Sub-sampled 5.5 x 5.5 mile area JPEG
  B&W NHAP
  • Sub-sampled 11 x 11 mile area JPEG
  CIR NHAP
  • Sub-sampled 8 x 8 mile area JPEG
  Tri-Decadal TM, and Tri-Decadal 1-5 MSS
  • approximately 450 meter sub-sampled JPEG in a UTM projection
  Tri-Decadal ETM+ Mosaics
  • approximately 285 meter sub-sampled JPEG in a UTM projection
  Tri-Decadal TM Mosaics
  • approximately 650 meter sub-sampled JPEG in a UTM projection
  For band combinations and further details on the browse image, see About Browse Images.
• Restore: Restores the list of scenes to the Scene List after placing an order. This is to be used when an order failed to be entered. (This option has to be used immediately after placing an order. Once another scene is added to the scene list, the restore list is gone and the restore option will be unavailable.)
  NOTE: All Aerial, Landsat, EO-1, ASTER and MODIS datasets are entered into the USGS shopping basket. Duplicate entries can be entered into this shopping basket, so users are advised to review the entire order before submitting the order for processing.
• Close: Closes the dialog box.
• Right-clicking: Right-clicking on the scene list displays a popup menu for the selected scene in the list. The menu is identical to the menu described for the scene list on the left side of the application window, with the exception that the "More..." option is not shown.

Search For Scene

The Search for Scene dialog box provides the capability to search for a specific scene using a known scene ID. This functionality is useful if a user wants to locate a specific scene quickly. This is especially useful for ASTER granules since the granule ID does not contain any information to identify the location or acquisition date of the granule.

The Search for Scene dialog has the following characteristics:

• Scene ID hint: The top of the window provides a hint for entering the scene ID for the current dataset. For example, for many Landsat datasets, a 16 digit scene ID should be entered. For an ASTER granule, the last 10 digits of the granule ID should be entered (i.e. if the granule ID is "AST_L1A.003:2012758270", enter the ten digits after the ":") For a MODIS granule, a 45 digit ID should be entered but a search can also be entered with part of the ID that includes the horizontal and vertical tile and some of the ID before and after the tile numbers.(i.e. if the granule ID is "MYD09A1.A2003001.h16v06.004.2004087194457.hdf", entering "A2003001.h16v06.004").
• Scene ID entry area: Below the scene ID hint is a text entry field to allow the scene ID to be entered. Most browsers and Operating Systems allow pasting text into this area.
• Search status area: Below the scene ID entry area, an area is reserved for displaying the status of the current search, or the results from the last search.
• Search Button: Pressing the search button initiates a search for the scene ID currently in the scene ID entry area. If a matching scene is found, the scene is displayed in the image display area.
• Close Button: Pressing the close button closes the dialog box.

Search Limits

The Search Limits dialog box provides the capability to limit the displayed scenes by various metadata fields. Note that the search limits options can vary for each dataset. The limits are applied immediately after being accepted and are applied when navigating to new dates. The following are available in the Search Limits dialog box:

• Start Year: The Start Year dropdown list allows the user to limit the earliest year for displaying scenes.
• End Year: The End Year dropdown list allows the user to limit the latest year for displaying scenes.
• Start Month: The Start Month dropdown list allows the user to limit the earliest month for displaying scenes.
• End Month: The End Month dropdown list allows the user to limit the latest month for displaying scenes.
• Max Cloud: The cloud cover dropdown list allows the user to restrict the displayed scenes to only those that meet specific cloud cover restrictions. By default, the USGS Global Visualization tool will display all browse images in the archive (Max Cloud 100%). A maximum cloud restriction of 0% (Max Cloud 0%) will display only cloud-free images. The cloud cover restriction can be set in 10% increments.

  NOTE: The cloud cover values for each scene are provided to GloVis by the data provider. They are typically estimates and may not accurately reflect the cloud cover actually present in the scene. The maximum cloud cover limit will not be available for datasets that do not provide cloud cover values. Not all datasets provide cloud cover values.

• Start Path: The Start Path dropdown list allows the user to limit the first path for displaying scenes.
• End Path: The End Path dropdown list allows the user to limit the last path for displaying scenes.
• Start Row: The Start Row dropdown list allows the user to limit the first row for displaying scenes.
• End Row: The End Row dropdown list allows the user to limit the last row for displaying scenes.

  NOTE: Limiting search by path and row values is only available for the Aster Sensor.

• Min Quality: The quality value dropdown list allows the user to restrict the displayed scenes to only those that meet the selected quality value restrictions, ranging from 0 (lowest) to 9 (highest). By default, the USGS Global Visualization tool will display all browse images in the archive (Min Quality 0). A maximum quality value restriction of 9 (Min Quality 9) will display only the highest quality images. The minimum quality is only available for Landsat datasets.
• Data Version: The MODIS data is periodically reprocessed and new data versions created. The data version dropdown list allows the user to restrict the data version displayed to a single data version if desired, or data from all versions can be displayed. The default is set to display all data versions.
• Show only scenes in the scene list: The Show Scenes From Scene List Only checkbox allows the user to limit the scenes displayed to those that are currently in the scene list. See the Scene List, Scene List Dialog Box, and Mouse Interface for information on navigating the scene list.
• Show only scenes in user defined area: The Show Only Scenes In User Defined Area checkbox allows the user to limit the ASTER and EO-1 scenes displayed to those that intersect the user-defined area. This option is only available for ASTER and EO-1 datasets.

  NOTE: If the user-defined area has not already been determined, the User Defined Area dialog box will pop-up to allow the user to define their area of interest. See the User Defined Area for more information.

• Ok: The Ok button sets the search limits to the selected limits and closes the dialog box. When viewing Landsat data, any displayed scenes that violate the search limits will be replaced with the scene with the closest date that meets the limits (or simply removed if no scenes meet the limits). For ASTER and EO-1 data, scenes that violate the limits will not be displayed or loaded from the server.
• Clear: The Clear button removes any previously set limits.
• Apply: Same as Ok button, but doesn't close the dialog box.
• Cancel: The Cancel button cancels any changes to the limits and closes the dialog box.

Example: To limit the displayed scenes to June, July, and August in the years 2000 and 2001 with 40% or less cloud cover and a quality value of 9, set the following:
1. Click on the Start Year drop down box and select 2000.
2. Click on the End Year drop down box and select 2001.
3. Click on the Start Month drop down box and select June.
4. Click on the End Month drop down box and select August.
5. Click on the Cloud Cover drop down box and select 40%.
6. Click on the Min Quality drop down box and select 9. (Landsat data only.)
7. Click on the Apply button.
8. The scenes that are displayed have the above limits applied.

NOTE: If a date range search limit is used, that search limit remains in effect when a new dataset is selected. If the newly selected dataset does not have any scenes in that date range, no scenes will be displayed. For Landsat data, the quality value limit will remain in effect when searching other Landsat products.

Swath Mode

The Swath Mode option appears on the Tools Menu for the ASTER and Landsat datasets. A swath consists of images acquired on the same day, along the same path, in consecutive rows. The default is for swath mode to be off. Selecting the menu item will toggle the mode on and off. A check appears next to the Swath Mode menu item when swath mode is on.

When swath mode is on, the browse images displayed are organized in swaths and the navigation control behavior changes to function on swaths instead of single scenes when it makes sense. The swath mode functionality differs in the following ways:

• A green border will highlight the scenes in the selected swath.
• When swath mode is first entered, the displayed scenes are updated to display swaths.
• For Landsat datasets, navigating by date will change all the scenes in the selected swath to the same date, if available.
• For ASTER datasets, navigating by date will work similar to non-swath mode, except that when a scene from a new swath is selected, the whole swath is displayed on top of the other scenes and highlighted with the swath highlight.
• Options are added to the image display area right-click menu to allow adding the scenes from a swath to the scene list or hide all the scenes from the swath.

User Defined Area

The User Defined Area dialog box provides the capability to limit a number of features for ASTER and EO-1 datasets to a specific region. This functionality is useful for users who are interested in a specific search area and want to avoid scanning through the many scenes that may be displayed.

To build the user-defined area, open the dialog box. At this point, the normal mouse interface is disabled and the following features come into effect:

Mouse Features:

• Add Points: Clicking a location on the image will add a point. As a user continues to click on the image, points are added and a polygon begins to form. Before a point can be successfully added, it is checked to see if it causes an intersection with a previously created line. Intersections make invalid polygons; therefore, invalid points are not allowed.
• Move Points: Clicking and dragging a point will move it to the new location. Just as with adding points, moving a point that causes intersections will not be allowed.

Buttons Available:

• Close and Apply Area: When selected, this feature closes the user-defined area and most functions will then be limited to that area.
  NOTE: This checkbox may be automatically selected if the user-defined area is manually closed by adding or moving points.
• Exit: Exits out of the User Defined Area dialog box. If the Close and Apply Area checkbox is set, the polygon will remain visible. Otherwise, it will be hidden.
• Clear: Removes all points and lines.
• Undo: Returns the user-defined area to the previous state before the most recent action.
  NOTE: After a clear, the undo memory is cleared after a new point is added.
• Goto: Moves the browse viewer window back to the user-defined area if the user has moved to a different location.



After the user-defined area has been completed and the Close and Apply Area checkbox has been checked, exit the dialog box. Date Selection features will only apply to scenes located within this area.
NOTE: To restrict all functions to the user-defined area, check the Show Only Scenes In User Defined Area box in the Search Limit Dialog Box.

File Menu Options

The Browse Image Viewer provides several tools on the File Menu for interacting with the application. The details of these options are described in the following paragraphs. Note that these options are only available when using the Java plug-in and the GloVis applet was granted sufficient privileges by the user answering "yes" to the security warning dialog that is displayed before the applet loads. If both of these conditions are not fulfilled, the File menu will not be available.

Save and Load Scene Lists

The user can save and load the contents of both the ordering scene lists and the hidden scene lists.

When the user selects one of the save options, a dialog box is displayed that allows the user to select the folder for storing the scene list file and the file name. The user may enter the required information and press the "Save" button, or cancel by pressing the "Cancel" button. After pressing the save button, the application writes the contents of all the scene lists (the ordering scene lists if the "Save All Scene Lists" option was chosen, or the hidden scene lists if the "Save Hidden Scene Lists" option was chosen) to the selected file.

When the user selects on of the load options, a dialog box is displayed that allows the user to select a previously saved scene list file for loading into the GloVis application. After selecting a file, the user can press the "Open" button, or cancel by pressing the "Cancel" button. After pressing the "Open" button, the application reads the selected file, verifies that it contains valid scenes, and loads the scenes into the ordering scene lists or hidden scene lists, depending on the option selected.

File Format: The scene list file that is saved on the user's computer is a simple text file. The file can be viewed in any application capable of reading a text file. Also, the user can edit the contents of the file to add or remove scenes if desired. Note: if the file is edited, the format must be preserved to be able to be read by the GloVis application. It is best to edit a copy of the original file in case something goes wrong in the editing process.

Here is an example scene list file:

        GloVis Scene List
        sensor=Landsat ETM+
        7029030000234750
        7030029000311750
        sensor=ASTER TIR
        AST_L1A.003:2007291967
        

The first line indicates the file is a GloVis scene list file. The second line indicates the dataset for the following scenes. After the second line, each line is interpreted as a scene id until the next "sensor=" line is found. The dataset name for a "sensor=" line is the same name that shows up in the collection menu of the GloVis application.

Download Visible Browse & Metadata

The user can download the original browse image files and metadata information files for the scenes currently visible on the display. The search limits dialog and user defined area can be used to limit the visible scenes.

When the user selects this option, a dialog box is displayed that allows the user to select the folder for storing the downloaded files. The user may enter the required information and press the "Save" button, or cancel by pressing the "Cancel" button. After pressing the save button, the application downloads the original browse image files and metadata files and writes them to the selected folder.

Download Path & Row Browse & Metadata

The user can download the original browse image files and metadata information files for the scenes that intersect the center cell of the mosaic. Only scenes that meet the current search limits are downloaded.

Note that for datasets such as Landsat and MODIS, all the scenes in the center cell that meet the current search limits are downloaded, not just the one that is currently visible.

When the user selects this option, a dialog box is displayed that allows the user to select the folder for storing the downloaded files. The user may enter the required information and press the "Save" button, or cancel by pressing the "Cancel" button. After pressing the save button, the application downloads the original browse image files and metadata files and writes them to the selected folder.

Download Scene List Browse & Metadata

The user can download the original browse image files and metadata information files for the scenes in the current scene list.

When the user selects this option, a dialog box is displayed that allows the user to select the folder for storing the downloaded files. The user may enter the required information and press the "Save" button, or cancel by pressing the "Cancel" button. After pressing the save button, the application downloads the original browse image files and metadata files and writes them to the selected folder.

Back to the Table of Contents

---

Frequently Asked Questions (FAQs)

Q: Where is the geographic location displayed?

A: As your cursor is passed over the locator map or any browse image, the geographic location is reported in the browser status bar (lower left margin of your browser window). The latitude and longitude is displayed in decimal degrees. For the locator map, the path and row (or tile number) under the cursor is also listed.

Q: Why such long response times?

A: Loading nine Landsat graphic images of 30-40K each, or dozens of ASTER graphic images of 5K each, may take from a few seconds up to 1.5 minutes, depending upon your internet connection. Once a set of browses has been cached, the response time should improve. You may continue interacting with the viewer while images are being downloaded.

Q: Why do some images appear to be tilted sideways?

A: This is an artifact of the Lambert Azimuthal Equal Area projection, which will produce more skewing near the edges of a region. Just remember that for any scene, the up-arrow moves from one row to the row above it, and not necessarily towards the top of your page. In the Map Layers menu, the North Arrow will show where "north" is relative to the mosaic or image shown.

Q: Why do the scenes sometimes look misaligned in the mosaic view?

A: The browse scenes used to create the Global Visualization inventory only have approximate geographic information available. This sometimes leads to inaccurate placement of the scenes.

Q: Why do some scenes appear to be "missing"?

A: There are several possible reasons:

• Landsat:
  1. The satellite does not acquire some areas of the world. For example, the Landsat program does not typically acquire data over oceans.
  2. The viewer will only display scenes that exist in the USGS archive. For many locations outside the U.S., there may be scenes that were collected by the sensor but the data is not archived or distributed by USGS EROS. These scenes may still be available from other International Ground Stations. (Please note that this data is not a product of USGS EROS; therefore, the price, available formats, and/or processing options may vary according to the data provider.) Please see the Landsat FAQ for details on searching for and ordering Landsat scenes.
  3. The viewer will only display scenes that have browse images available in the USGS inventory. Some scenes (particularly Landsat 5) do exist in the USGS archive, but they do not yet have a corresponding browse image. To access Landsat 5 TM data for which there is no browse, you will need to run a search on Earth Explorer. As the TM browse images become available in the future, they will be continually added to the USGS Global Visualization tool.
• ASTER and EO-1:
  1. ASTER and EO-1 scenes are typically collected on-demand. The programs do not attempt to get full coverage like the Landsat program.
• Lambert Azimuthal Equal Area Regions:
  1. For Landsat, ASTER, and EO-1, different regions of the world are displayed using different parameters for the Lambert Azimuthal Equal Area projection. In the areas where two of these regions meet, only data from one of the regions can be displayed at a time.

Q: Why doesn't the URL update when navigating, and why can't I save a bookmark that shows the viewer window that was last displayed when the bookmark was created?

A: The image browser web page is an independent Java applet, so any actions within the applet (such as selecting a new location, selecting a new date, and changing the viewing mode) will not ever affect the main URL to which the browser is pointed.

Q: Why does the "BACK" button take me all the way back to the home page, rather than to the browse image I was viewing last?

A: The image browser webpage is an independent Java applet, which means the URL is not changing as a search is run. Selecting the "Back" button of the browser window will only take you to the previous screen (URL), which is the home page.

Q: How can I print or save a browse image?

A: If you want to print a single browse image, the best way is probably to use the "Show Browse" feature to open a separate window which will allow the user to print and/or save the browse image. Metadata can be printed in the same way using the "Show Metadata" feature. The original browse images and metadata can be downloaded using the options in the File menu. There is also a print option under the Tools menu that will print the entire main window of the Java applet.

Q: What if I want to purchase precision- or terrain-corrected Landsat data?

A: The Tri-Decadal and MRLC 2001 products that are available through the Global Visualization Viewer (GloVis) are terrain corrected. However, other Landsat data products need prior approval to purchase precision- or terrain-corrected data. GloVis now utilizes a new feature through the Earth Explorer Shopping Basket that allows users to login from different applications. If you are approved to purchase precision- and terrain-corrected data, those options will be available in the Shopping Basket after you login. Note: Under current USGS policy, the distribution of precision- and terrain-corrected data is restricted to only USGS researchers for Landsat 7 ETM+, and to only Approved U.S. Government and its Affiliated Users (USGAU) for Landsat 4/5 TM and Landsat 1-5 MSS.

Q: Why do latitude and longitude grid lines sometimes appear in the water map layer?

A: The source used by GloVis for the water map layer contains the latitude and longitude grid lines. In the future, we may be able to locate a data source that does not contain the grid lines.

Q: Why are the Latitude, Longitude, and Select Sensor selection boxes on the Home page not displaying or fully displayed on the page?

A: The browser is configured to use a larger font than the page is designed for. To change your browser font configurations do the following according to the type of browser you are using.

• Netscape 6.0+
  1. From the menu bar on your browser window, click on View.
  2. Then click on Text Zoom and select any size of text that is 100% or lower.
• Internet Explorer 5.0+
  1. From the menu bar on your browser window, click on View.
  2. Then click on Text Size and select either medium, smaller, or smallest.

Q: Why does the Shopping Basket, Metadata, or Browse Image fail to appear when I click the 'Order', 'Submit', 'Show Metadata', or 'Show Browse' buttons?

A: This is usually caused by a browser or 'add-on' security product that incorrectly blocks pop-up windows that it should not be blocking. In GloVis, the shopping basket, metadata, browse image, and other windows can be affected by this. Refer to your browser or add-on security product documentation to learn how to disable the pop-up blocking for the GloVis web site. The following products have been known to cause problems:

• Windows XP Service Pack 2 added pop-up window blocking to Internet Explorer.
• The "Google search bar" that can be added to browsers has an option to prevent pop-up windows from appearing.
• Some 'add-on' security products (like Norton Internet Security and others) have a feature to block pop-up windows.

Note: Some of the products allow temporarily bypassing the pop-up blocker by holding down the "Control" key when clicking on a button that pops up a window.

Q: Why do the dates for some of the MODIS images on GloVis not correspond with imagery for the same date provided through the MODIS Rapid Response System?

A: The data from the Rapid Response System (rapidfire) site are daily data collections. The MODIS products on GloVis are a collection of both daily and composite products.Refer to the About Browse page for a description of which datasets are daily and which are composites. As the daily data and multi-day composites are different products, they won't look the same and the dates won't be the same. The date that appears in the Scene Information field for daily data is the acquisition date, but for multi-day composites it is the first date of the collection period.

Q: Why do I get a page indicating I need a newer version of Java?

A: GloVis requires Java 1.4 or newer. If the version of Java detected is older than that, the page indicating a new version of Java needs to be installed is displayed. The page provides instructions for updating Java. Note that some browsers do not allow the version of Java to be detected properly and this page might be displayed when the required Java support is already installed. A link to go to the GloVis applet page is provided, but the page will not work if Java 1.4+ is not installed.

Q: If I update to a newer version of Java, will it erase my existing version of Java?

A: No. It installs a newer version of Java while leaving the existing versions intact. This is useful for a site that has only certified their application on an earlier version, and another site that requires a newer version.

Q: How do I download Imagery?

A: When the "Downloadable" message is shown in the image display area, the full resolution data may be downloaded at no charge. To download the imagery, first select (click on) the scene you would like to download. Then on the bottom portion of the left panel under 'Scene List', click 'Add' and the scene will be added to the list. The scene will be highlighted in the 'Scene List' box, and the 'Download' button will become available. For each scene, click the 'Download' button. A pop-up box will appear informing you of the amount of time the download will take and asking if you would like to continue. To download, click 'Yes'.

Back to the Table of Contents

---

Contact Customer Services

Customer Services
U.S. Geological Survey
Earth Resources Observation & Science Center (EROS)
47914 252nd Street
Sioux Falls, SD 57198-0001

Tel: 800-252-4547
Tel: 605-594-6151
TDD: 605-594-6933
Fax: 605-594-6589
Email: custserv@usgs.gov
Business Hours: Monday thru Friday, 8:00 a.m. to 4:00 p.m., central time

Back to the Table of Contents

DOI

USGS HOME

Biology

Geography

Geology

Water