1
$\begingroup$

When researching this question I came upon a presentation entitled Enabling a Fully Interoperable GNSS Space Service Volume; slides 12, 24, 25, 26 are also shown below. The idea is that while GPS satellites concentrate most of their radiated power at the earth, there is some "spillage" past the edge of the earth and out into space, from both the main lobe and side lobes, depending on the particular GPS satellite configuration.

Signals may be weaker and good fixes may be intermittent, but for many space applications this can still be extremely useful.

This answer has a great discussion (and nice plots!) of radiation patterns.

The last slide suggests the example of a mission returning from the moon, which I assume is a potential future mission.

Apart from the signal strength data from a piggy-backed experiment aboard AO-40 (and here), has GPS ever been actually used or even validated or tested as a potential source of supplemental navigational information beyond Geostationary orbit?

enter image description here

enter image description here

enter image description here

enter image description here

enter image description here

$\endgroup$

marked as duplicate by kim holder Apr 10 '16 at 20:58

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

  • $\begingroup$ A related question $\endgroup$ – uhoh Apr 10 '16 at 9:18
  • $\begingroup$ Also "get a signal" is not the same as "source of supplemental navigational information." You need FOUR GOOD signals to get a standard, valid GPS fix that could potentially be used for navigation! $\endgroup$ – uhoh Apr 10 '16 at 14:02
  • 1
    $\begingroup$ The question I linked I believe is using signal to mean not just a signal from a single satellite, but sufficient to establish location. I feel like the question is essentially the same as the one linked, namely can GPS be used high up, but I'll give you there is some slight difference. There is another question that I found that is quite similar, space.stackexchange.com/q/565/25 $\endgroup$ – PearsonArtPhoto Apr 10 '16 at 19:47
  • $\begingroup$ @PearsonArtPhoto that question/answer definitely has everything - I should have found it right away, not sure why I didn't. The paper you link to in your answer is fascinating - I didn't realize the AO-40 experiment generated real solutions! Thanks for your help! Should I delete this question or leave it as a pointer to the original? $\endgroup$ – uhoh Apr 11 '16 at 3:38
  • 2
    $\begingroup$ Leave it. Duplicate questions aren't always obvious (This one took me 2 tries, and a fair bit of time to find), so having a pointer like this to them helps others in the future find the one with the answer. $\endgroup$ – PearsonArtPhoto Apr 11 '16 at 7:11