The Dapper Data Viewer (aka DChart) allows you to visualize and download in-situ oceanographic or atmospheric data from a Dapper OpenDap server. Features include an interactive map that is draggable, an in-situ station layer that allows you to select data stations, and a plot window that allows you to plot data from one or more stations.

• Click on a dataset in the Datasets panel. The map display will be updated to show the locations of the stations that are part of the dataset.
• Click on one or more variables in the Variables panel. Multiple variables are selected by pressing the Ctrl key while clicking on a variable.
• Select one station by clicking on the station or select multiple stations by dragging the cursor over a region.
• Click on Plot Selected to plot data from the selected stations.

In-situ data consists of a set of datasets. Each dataset consists of a group of variables. Each variable represents a measurement of physical data made at a series of stations that represent where and when the measurement was made. For example, in-situ oceanographic data may consist of a set of measurements of temperature and salinity made by a set of ships at specific latitude,longitude, and time locations.

In order to display or download data in DChart, you :

• Select a dataset.
• Filter the stations (optional).
• Select one or more variables.
• Select one or more stations.
• Select a plot or download type.
• Plot or download the data.

When you select a dataset, a set of stations corresponding to the default range displayed in the Station Filter box is displayed on the map. You can select a different set of stations by entering new values in the Station Filter box and clicking the Apply button. You can reset the displayed stations to the default value by clicking on the Reset button.

You can save the current page by clicking on the Link to this page button. You will be redirected to a URL that saves the currently selected stations, datasets, variables, and station filter, as well as the region of the map that you are viewing. You can then bookmark this link if you wish to return to the page, or e-mail it if you want to share the link with others.

When DChart is intialized, the map is in select mode. This allows you to select stations. You can change the map to drag mode by clicking on the drag button; this allows you to center or drag the map. To set the map back to select mode, click on the select button.

	Pan up
	Pan down
	Pan right
	Pan left
	Zoom in
	Zoom out
	Reset map to full display
	Change to drag mode
	Change to zoom mode

Left click and drag	Drag the map
Double click left button	Center the map
+	Zoom in
-	Zoom out

Left click	Select/deselect a station
Left click and drag	Define a region for loading stations/select stations in region
+	Zoom in
-	Zoom out

Left click on axis	Display a dialog for changing the range of the axis
Left click on data area	Pan
Ctrl-Left click on data area	Reset to full view