26 Mar
2013
26 Mar
'13
11:58 a.m.
On 3/25/2013 6:42 PM, Ken Ernandes wrote:
- If you decide to give the users the ability to input their location, them the option to provide either a single minimum elevation angle or a local map -- i.e., 360 individual minimum elevations as a function of Azimuth. It's much easier to project this and the user is generally interested in an unobstructed LOS with respect to his/her location.
It's not the best resolution but in the image below, you can see how there are "cut outs" in the circles surrounding NASA's ground stations - the software has clearly implemented the idea Ken outlined above. For example, there is apparently some obstruction to the south east of the Hawaiian tracking station. If the sub-satelite point is inside the white line it's AOS. The surface of the earth visible to the shuttle, on the other hand, is simply a red circle, just faintly visible in this image.
http://vault.newsfromspace.com/missions/sts114/STS114_land-5.jpg
-Joe KM1P