[AR] Re: Lunar GPS navigation.
- From: <anthony@xxxxxxxxxxx>
- To: <arocket@xxxxxxxxxxxxx>
- Date: Tue, 30 Jul 2019 19:51:35 -0400
I don't have any details yet but I was informed that NASA has added it to
the payload our next launch campaign and it's a big deal for the moon
program all of a sudden. Apparently there's an advantage to utilizing the
two constellations as opposed to just one. I don't know why it has to be
flown to qualify it, I just work on the loud part of the experiment. This
mission has a small second stage with an ACS so that may have something to
do with it.
Anthony J. Cesaroni
President/CEO
Cesaroni Technology/Cesaroni Aerospace
http://www.cesaronitech.com/
(941) 360-3100 x101 Sarasota
(905) 887-2370 x222 Toronto
-----Original Message-----
From: arocket-bounce@xxxxxxxxxxxxx <arocket-bounce@xxxxxxxxxxxxx> On Behalf
Of Henry Spencer
Sent: Tuesday, July 30, 2019 6:33 PM
To: Arocket List <arocket@xxxxxxxxxxxxx>
Subject: [AR] Re: Lunar GPS navigation.
On Tue, 30 Jul 2019, Anthony Cesaroni wrote:
Is anyone on the list familiar with a lunar GPS scheme that combines
the Navistar and Galileo constellations?
The lunar navsat concepts that I'm vaguely aware of -- not something I
follow closely -- all use new lunar-orbit satellites. The existing
Navstar/GPS and Galileo constellations are all in one small area of the
lunar sky, giving poor navigation precision (Geometric Dilution of Precision
is the buzzphrase) at the best of times... and they're totally invisible
from half of the Moon.
There's no reason why a GPS-type system wouldn't work in lunar orbit, given
about the same number of satellites as the Navstar constellation for Earth
(it doesn't work without four satellites simultaneously visible, and
preferably more). If you want to use a smaller number of satellites, you
can reinvent Geostar, which requires that the ground terminals transmit as
well as receive (GPS is receive-only because of its military origins), and
can do low-bandwidth messaging too. If you can settle for occasional
position updates rather than fresh positions every second, you *might* be
able to reinvent Transit, which will give you a fairly precise position from
a single pass of a single satellite, although it might not work quite as
well on a world rotating as slowly as the Moon.
Henry
Other related posts:
