Although not all questions pertaining to CoastWatch data products can be answered on this website, most questions fall into one of the categories listed below. If your question is not answered here, please submit your query to Shawna Karlson, contractor for the CoastWatch Central Help Desk.

• General
• Data Formats
• Ocean Color
• Sea Surface Temperature
• Ocean Surface Winds
• Applications of CoastWatch Data
• Archived Data

General

1. What is CoastWatch?

CoastWatch is a NOAA-wide program comprised of Central Operations and six regional nodes. Our mission is to process satellite data and provide oceanographic products to Federal, State and local marine scientists, coastal resource managers, and the general public. Data are processed near real-time, therefore are usually only a few hours old. Each CoastWatch Node has a unique website for data distribution and specialized products and projects which utilize CoastWatch data. Links to these sites are found on the Regional Offices page.



2. How are CoastWatch data used?

There are many uses for CoastWatch data. For instance, temperature images are used to locate fishing spots and for forecasting weather. Ocean color images help scientists track biological changes in the ocean, while sea surface wind images are used primarily by meteorologists and boaters.



3. Does CoastWatch cover only the coast?

No, CoastWatch covers more than just the coastal areas of the U.S. Depending on the region of interest, there could be data covering as far out as 500 nautical miles off shore or the entire Laurentian Great Lakes. In addition to these regions, CoastWatch will also be providing data for the open ocean. Look for OceanWatch to be coming soon as we continue to expand our region areas and move toward global coverage.



4. Does CoastWatch cover any of the lakes throughout the U.S.?

No, CoastWatch does not normally provide data for any of the lakes throughout the U.S., other than the Great Lakes. However, for the 2000 Winter Olympics in Salt Lake City, CoastWatch provided data for the Great Salt Lake. This SST data proved useful for meteorological forecasts and is still being processed today. The data can be retrieved from the Satellite Active Archive, an office within NOAA/NESDIS.



5. What satellites does CoastWatch use?

CoastWatch provides data from several satellite platforms. For more detailed information, follow the 'Data Products' link to the left.
• SST: POES/AVHRR, GOES/Imager, MODIS/Aqua and Terra, and as an experimental product TRMM/TMI
• OC: GeoEye/SeaWiFS and MODIS/Aqua and Terra
• Winds: DMSP/SSMI and QuikScat/SeaWinds




6. Does CoastWatch have aerial photos?

No, CoastWatch does not have aerial photos. We provide only satellite ocean remote sensing products for regions around the U.S. These products can be found by using the "Product Search" link to the left.



7. What CoastWatch websites are available?

Central Operations maintains the CoastWatch home page and the Ocean Product Server, for SeaWiFS only. Each CoastWatch Regional Node has a unique website for data distribution specific to their region. Links to these sites are found on the Regional Offices page. In addition, CoastWatch has an Anonymous FTP server for accessing the data. Presently, only AVHRR and MODIS products are available, but all other products will be made available soon.



8. Where can I access the CoastWatch products?

All CoastWatch products can be found by using the "Product Search" link to the left. This is a search interface that provides access to the satellite ocean remote sensing data and products CoastWatch has to offer. Data selection is broken down into the following categories: geographic region, product, sensor, satellite, and date. To search the data by sensor only, use the Index of Data.



9. How accurate are CoastWatch products?

Accuracies vary with each type of sensor and processing used. Validation for most products are available through websites that describe the methodology and techniques used to create CoastWatch products. The Validation section of the Links page provides access to these sites.

Data Formats

1. What is the CoastWatch data format?

CoastWatch supports a variety of data formats for satellite images. The primary format is the CW HDF (Hierchical Data Format), which will retain the special data parameters and metadata required for scientific analysis. Image products may be available in GeoTIFF, PNG, or GIF formats. These products are easily viewable in graphics applications or web browsers. More information on these formats is located on the Data Formats page.

Ocean Color

1. Do I need to be a 'registered' user to access ocean color products?

No, you do not need to register for MODIS ocean color products, nor for SeaWiFS imagery. The SeaWiFS imagery purchased and processed by NOAA can be viewed online through this website, using "Product Search". However, if you need access to the data (i.e., HDF files) or near real-time SeaWiFS imagery (i.e., coastal management, resource monitoring) then you must become a registered user, due to licensing contracs with GeoEye.



2. Why is the SeaWiFS data restricted?

The satellite that supports SeaWiFS is a commercial platform owned by GeoEye. Because this is a commercially owned and operated platform, NOAA must purchase data subject to a contract that defines the appropriate use of ocean color data derived from SeaWiFS. NOAA purchased data is restricted to "civil marine" operational use and is intended for civil authorities (federal, state, and local governments) for watershed management and monitoring. Data for research purposes may be obtained from NASA under a separate agreement with GeoEye.



3. How do I become an Ocean Color User of SeaWiFS data?

You must meet the following criteria:

1. be a qualified NASA SeaWiFS user (Dear Colleague Letter in place) with a need for NRT processing/NOAA algorithms in support of NOAA projects
2. be a coastal manager (local, state, federal government) with a need for NOAA operational data for civil marine management
3. have an understanding of the NOAA CoastWatch SeaWiFS Data Use Policy

If you meet these criteria or have additional questions, then contact Kent Hughes, CoastWatch Program Manager to request access. If you only need SeaWiFS data solely for research purposes, you should request data from the NASA SeaWiFS Project.

Sea Surface Temperature

1. How do I download the MODIS/Aqua data to bring into ArcView 3.2 as a grid file?

Since CoastWatch doesn't provide the binary data in FLT/HDR format for MODIS, you can convert the GeoTiFFs (which contain 8-bit integers) to grids and calculate the SST from the GeoTIFF values using the below equation. In doing so, you must have the Spatial Anyalyst extension ON and the TIFF 6.0 extension OFF.

(((SST_grid*0.14575))-0.8676)

The result should be a floating point grid containing the SST values. Remember, the mathematical order of operations in ArcView 3.x is left to right.

Ocean Surface Winds

1. What is the difference between the two CoastWatch winds products?

CoastWatch provides near real-time ocean surface wind products with data from the QuikSCAT satellite and the Defense Meteorological Satellite Program (DMSP). Although the ocean surface wind products appear similar, each product has unique characteristics dependent on sensor characteristics and wind derivation methods. The QuikSCAT products use color as well as wind-barb notation to depict velocity (wind speed and direction), while the SSM/I products show only wind speed.

Applications of CoastWatch Data

1. What software is available that can read CoastWatch data formats or help in visualizing the data?

CoastWatch provides various types of software and utilities for data users. One in particular, is the Software Library and Utilities package. This package will allow data users to easily manipulate and visualize satellite data in both the new CoastWatch HDF (.hdf) files and the older CoastWatch IMGMAP (.cwf) files. The utilities are composed of both graphical and command-line tools that can read CoastWatch data and allow the user to convert or customize the display of CoastWatch products.

The latest version of the software and utilities package, 3.1.7, is available for free through this website. New versions are released periodically.



2. Can I use the CoastWatch Utilities software for all of the CoastWatch products?

No, not yet. The CoastWatch Utilities software requires the data to be in the CoastWatch HDF format or the CoastWatch IMGMAP format. Currently, the Utilities will only work with POES/AVHRR SST. Soon, we will offer all of our products in the necessary format. For the other data sets that may be in the appropriate format, additional modifications are still being done to the software in order for the functions to work properly.



3. How can I customize the color tables used in the CoastWatch Data Analysis Tool and/or Utilities?

In addition to the default set of palettes, users may create their own palette files and store them in the .cwf/palettes subdirectory. Palette files have an XML format which can be found under 'Help' - 'Help and Support' within CDAT.



4. Is there a site that I can get Java so I can run the CoastWatch Utilities software?

Yes, Windows and Linux users can try the "Download J2SE JRE" from here.

Archived Data

1. How do I obtain data no longer available through this site?

Sea Surface Temperature and Ocean Color data are stored at the Satellite Active Archive. To purchase data, you must first register on the website. Once the order is placed, instructions will follow on how to retrieve the data, which will be staged on an Anonymous FTP server.

If the ocean color data is no longer available, checkboxes will show beneath the thumbnail. Selecting the appropriate box and pressing the "SAA" button will prepare an order for submission to the Satellite Active Archive. In order to access the SAA for ocean color products, you must first be a CoastWatch Ocean Color User registered with the SAA. To register, follow the "SAA Register" link from either the Ocean Color Browse/Search interface or after submitting a filelist for retrieval.



2. How do I get the MODIS imagery for the dates I'm interested in?

All current MODIS Aqua and Terra data are available in HDF format on this website for up to 14 days. However, PNG and GeoTIFF's are available from 6 - 24 months. Archived data are available through NASA Distributed Active Archive Center and should be used for any data needs before the last 14 days.



3. How do I get QuikScat winds data for a specific time frame?

   QuikScat/SeaWinds HDF and SHP files are available on this site for up to four weeks. GeoTiff's and PNG's are available up to five months. For dates earlier than these, please visit NASA JPL.