Week 4: Using Satellite Data to Study the Ocean
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Getting to Know Giovanni
This week, you'll use Giovanni to create a visualization that you can use in your teaching. You will also use Giovanni to study chlorophyll concentration in Chesapeake Bay. Click here to open Giovanni in a new window. Use the information below to help you get acquainted with Giovanni and how it functions.
The Giovanni Interface
The interactive map tool allows you to choose any location in the world using a manual selection tool or by specifying a pre-defined area from a list of options. You can pan and zoom using the navigation tools, and add or remove boundaries and coordinate grid lines using the overlay tools.
Zoom in or out, and pan the map
- Click once on the Zoom in button. The view zooms at the center of the map and displays Africa.
- Click once on the Zoom out button. The view returns to the previous zoom level.
- Click the Zoom in button once or twice. Use the directional arrows on the pan button to pan up, down, right, or left across the map. Click on the crosshairs in the middle of the pan tool to center the map on the Greenwich Meridian (0° longitude) or the International Date Line (180° longitude).
- You can also use the Drag tool to click and drag to pan the map in specific locations.
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Select an Area of Interest
The first step for using Giovanni is to select an area of interest in which you would like to explore data.
- Select the red box/"+" icon to activate the Click and Drag Selection tool. Click and drag a bounding box on the map to define your area of interest.
- To manually set the area of interest, type the bounding latitude and longitude coordinates into the text boxes along the bottom of the map. Click the Update Map button to refresh the map to show the region within your defined boundaries.
- Use the image icons at the top right of the map tool window to set the base map to NASA Blue Marble imagery, a Landsat 7 mosaic map, or a political/coastline boundaries map.
- Click the Show/Hide map overlays button to turn political boundaries/labels, coastline boundaries, and coordinate grid lines on or off. Click the button a second time to hide the overlay options.
- Use the globe button to select an area of interest (AOI) from a list of pre-defined areas including global AOIs centered on the Greenwich Meridian (GM) or the International Date Line (DL).
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After you've chosen the geographical area you want to study, choose the data you want to look at in the Parameters section. Ocean Color Giovanni data sets include: SeaWiFS data, MODIS-Aqua and MODIS-Terra' data (MODIS-Terra provides sea surface temperature data only), and "GSM" bio-optical products derived from SeaWiFS and MODIS-Aqua data. GSM stands for Garver-Siegel-Maritorena, the last names of the researchers who have provided the data products.
- Use the check boxes to choose what information appears (parameter, units, climatology info).
- Click on Show Notes... to learn more about Parameter options.
- Click on any linked text in the Parameter or Climatology info columns for more information.
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Set Temporal Boundaries
Set the beginning and end dates for the time period you wish to study.
Select Visualization Type
Giovanni gives you 12 different visualization options for your data, including animations, lat-lon maps, and time series plots.
- Choose the type of visualization you want to create from the pull-down menu. To learn more about each of the visualization types, click on the Visualization Help link. Click the Edit Preferences button to customize your visualization.
- Click the Generate Visualization button to create your data visualization or click the Reset button to reset all of the parameter, temporal, and visualization settings back to their default options.
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Create a Giovanni Visualization for Your Own Use
Use Giovanni to generate a visualization that you could use in your own classroom.
- Select any geographical area, data set(s), time period, and visualization type.
- Save your visualization to your computer as a GIF or JPEG image file. On a PC, right-click on the image and on a Mac, control-click on the image to download and save it. Save the image into your Eyes in the Sky II folder and give it a name that will make it easy to identify later.
This is the image that you'll post to your discussion section.
Movies on this Page
How to download movies
- Click the link to go to the SERC media library listing for the movie. The record will open in a new window.
- On the SERC media library page, right-click (Win) or control-click (Mac) the link (below the movie on the Flash version pages) to download the movie file to your hard drive.
Flash Video Versions
Download these version to play on your iPod or iPhone.