Saturday, 10 December 2011

Satellite Tracking using AR on my Android

In my quest to get better reception of the Russian navigation satellites I have installed the Satellite AR application on my Orange San Francisco Android phone. Up to now I have used a simple compass and a pass prediction to work out where the satellite will appear and how I think it will travel across the sky. Then after having acquired the signal fettling the antenna to get the best signal. While it has given me good results I wasn't convinced I was getting the best signal I could.

The serious method of doing satellite tracking is to use a motorised azimuth antenna rotor connected to a PC running some prediction software. The commercial solutions are hideous expensive and while there are plenty of home-brew solutions available it would still mean a lot of expense in terms of time and money, so I looked for an alternative method.

Then I discovered this brilliant Android app! I used it for the first time late last Sunday evening when it was dark and was suitably impressed, so had a proper attempt in the fading daylight today and was able to take a few photos.

The AR stands for augmented reality and what you get is a view of the sky through the phones camera and overlaid are the positions of any satellites in view. The application uses the phones GPS, compass and accelerometers  to work out where the camera is pointing, so you get to see the satellite as if it were visible in the sky. It is really quite spooky!.

I selected the Russian LEO Satellites option for a pass this afternoon and using a couple of elastic bands to lash the phone on to the antenna post I could then point the antenna directly at where the satellite was supposed to be. The satellite today being COSMOS 2429 on 150.030MHz. The main thing I seem to have been doing wrong was while I had the antenna point in the correct bearing I had the elevation far too low. I needed to be pointing it much higher up in the sky.

I was able to got some excellent audio, with the signal still booming in when it had disappeared off the display. I have enclosed a small extract below, note some of the signal fading is because I was trying to take the photos while holding the antenna in my other arm... it gets quite heavy!

Cosmos 2429 10122011 by nerdsville

I brought my phone back in January for the pricey sum of £80. While not the most powerful Android around, only having version 2.1 of the operating system and is prone to crashes and resets it is probably one of the best purchases I have ever made, it is even better now I can use it to chase down signals!

1 comment:

Brett Martin said...

Nice work, Last year I built a cross-di-pole antenna, and download pictures from NOAA sats with yasue vx1 radio. The results were good nice pics decoded in realtime in my garden with laptop. Now I want to do that with an android device, do you know of anything android to do that?