Create a Region object using a .kml file

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Nate McCoun 6613f484be0f7
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Joined: Mon Apr 08, 2024 1:43 pm
Create a Region object using a .kml file

Post by Nate McCoun 6613f484be0f7 »

Are you interested in doing contact analysis with a specific area on Earth or the Moon?
FreeFlyer's Region object allows you to create a closed contour area on a Celestial Object's surface, defined by a series of planetodetic latitude and longitude points (also called vertices). A Region must include at least 4 points and must be a closed polygon, with the same values for the first and last points. The Region object is used to identify when a Spacecraft is over an area on the surface of a Celestial Object, or when a Spacecraft Sensor "sees" a region. Regions can be viewed in a ViewWindow object or using the View or Map commands.

With your FreeFlyer installation you have access to a few pre-defined Region objects including the Continental United States (CONUS.reg), Canada (canada.reg), and Africa (africa.reg). To streamline the creation of more complex Regions, you can use a .kml file and the attached KMLtoRegion Procedure. The Procedure takes arguments for a String for file path for the .kml file, Arrays for latitude and longitude, a Region object, and a Variable for the Celestial Object. The attached Mission Plan demonstrates reading in a .kml file for Japan and outputs a Region object and a 3D visualization of the created Region.

Note: You can use Google Earth to create waypoints and export a .kml file.

Once the Region has been created, you can load it into any Mission Plan for contact analysis.
Attachments
Japan.kml
Japan border .kml
(21.8 KiB) Downloaded 2498 times
MakeARegion.MissionPlan
(5.43 KiB) Downloaded 2488 times
KMLtoRegion.FFProcedure
Procedure to convert .kml waypoints into Region vertices
(1.43 KiB) Downloaded 2484 times