AO-40 experiment leads successful acquiring of GPS signals on Moon

Steve, the web site Heavens Above usually has good info. Please let us know if this works for you and if you're able to utilize it.

Good luck & 73, John WØPV

AO-40 - Orbit Home | Info. | Passes | Close encounters




View from above orbital plane



View from above satellite


Ground track

The orbit data is extracted from the following two-line orbital elements,

1 26609U 00072B 25070.29607624 .00000012 00000-0 00000-0 0 9995
2 26609 9.0567 55.0547 7976061 39.3588 357.2869 1.25589491111692

Epoch (UTC): 11 March 2025 07:06:20
Eccentricity: 0.7976061
inclination: 9.0567°
perigee height: 966 km
apogee height: 58853 km
right ascension of ascending node: 55.0547°
argument of perigee: 39.3588°
revolutions per day: 1.25589491
mean anomaly at epoch: 357.2869°
orbit number at epoch: 11169

 

GPS sats are not geostationary.

 

Try the Heavens Above page. Here are all satellites listed. Get to the point "Satellite Database" and then enter "AO-40". The dash is important for the choice, because its a sharp search.

https://www.heavens-above.com

 

Right! GNSS data includes an occasional Ephemeris packet giving the precise location of each satellite (marked by its own PRN code) so the receiver can figure out the starting location of the signal. Precise orbits are maintained by DoD and uploaded to the GNSS constellation using a number of measurement techniques including satellite laser ranging. US Naval Observatory and the Global Geodetic Observing System (GGOS), which sets the terrestrial reference frame and UT1 (Earth time locked to celestial time), are also involved.

 

Great work everyone!
Congratulations to all involved and observers.
Wonderful positive accomplishments to focus on and to satisfy our quest to learn how things work.
Ham radio and space/science accomplishes much.
73 all
Larry ns4q

 

Need APRS on the moon to

 

I believe lunar APRS OPs, with no huge AFSK legacy we've got on the Earth, would choose FELINET with it's more efficient FSK instead of classic AFSK we're used with. Otherwise, it's the same APRS we know.

 

So what does the GPS say? You are at X lat and lon with an altitude of 240,000 miles

 

Now that is awesome info thank you so much. Dave kk5up

 

How interesting that GPS has this type of application. Was it designed with this in mind or was it a “happy accident”?

In a similar vein, as the moon becomes more populated is there utility in establishing a GPS constellation orbiting the moon?

 

I would think so, eventually; but durable orbiting (or perhaps less likely, lunar surface) communications links with the far side are probably a higher priority. It could even be that meeting both needs is accomplished with the same orbiters.

 

When the lunar APRS port is connected to the digital commercial port for to send SMS to a mobile on Earth, it can be fun. So a steady lunar APRS got really potencial.

 

https://www.n2yo.com/satellite/?s=26609#results

 

It allows you to resolve where you are relative to the satellites. How the mapping software presents that information to the end user, is another matter.

 

I came late to the game on AO-40 I managed to make 1 cw contact before it died.