Loading Data
There are six different ways to load imagery data into PEP: use the Adventure Button, use the Fill Screen button, go to a favorite, enter a specific coordinate, select a gazetteer feature or open a file.
Adventure/Go Someplace Button
When you're interested in adventure, click the "Go Someplace" icon or select "Go Anywhere" from the File menu. This makes GeoVirgil randomly pick a entry out of the Mars gazetteer and download the imagery data for it from a NASA JPL server. Depending on the speed of your internet connection, this might take several seconds or several minutes. After the download is complete, the data will be displayed and a window will pop-up explaining the feature.
Fill Screen With Imagery Button
After you click on this button, PEP will fill in the blank blue regions with imagery from NASA JPL data servers. Before you click on this button, just pan and zoom the map to adjust what data will be downloaded. If you're not on the internet when you click on this button, you'll get an error.
I like to start with "Go Somewhere" until I find something interesting (which never takes long). Then I use "Fill Window With Data" as I follow a fluvial feature to its source or see how large a crater field is. It is a good way to explore.
From The Menu
The other options for downloading imagery data are all items on the "Imagery" menu.
Go To Coordinate
You can load data just by specifying the planet and geodetic coordinates (latitude and longitude) you want. When you select "Go To Location", a special panel appears:
Currently, GeoVirgil can only download data from Mars and Venus.
Go To Feature
There are thousands of named features on the planets. PEP lets you request data based on a feature's name or the geological type. When you select "Go To Feature", this window appears:
With this window, you select the planet, geological feature type (crater, mountain, etc.), feature name, and size. You are free to enter as much or as little of this information as you want. For example, if you know you want to see the crater named Gusev, just enter its name in the Feature Name field. If you want to see craters on Mars between 20 and 30 kilometers in diameter, just enter that information.
When you enter a feature name, you can use the wildcard character ("*") as the first or last character in the name.
After you enter the data, you will get a list of the features that match. For example:
This list contains all the entries in the gazetteer that matched you search parameters. You can now pick the entry you want and click "Go". Then, GeoVirgil will obtain the requested data and display it.
Go To Favorite
With PEP, you can explore the planets. As you stumble across interesting regions, you can save them as a "Favorite". If you select File->Save As Favorite, you'll be asked for a name. The next time you display the File menu, the "Load Favorite" menu will show all the favorites you have created. Since the NASA data files for favorites are stored on your local drive, they load very quickly.
Open File
You can buy NASA data CDs from the National Space Science Data Center or download individual files from various NASA servers. Once you have the data, you can use GeoVirgil display these files. Clicking on "Open File" displays a pretty standard dialog where you can select as many files as you want or specify an entire directory.
Previous Home Next