As part of the Advanced Master Space Communication Systems, we have the project to build an antenna to receive weather image from NOAA satelitte.
Our project was divided in several parts.
At first we have studied, NOAA agency and its satellite. We focused precisely on how the APT signal is created and transmitted.
Secondly, we compare different type of antenna. For a question of cost, we have decided to use an omnidirectional antenna. Our comparative study allowed us to conclude that the Double Cross Antenna was the best solution according to our criteria.
Once we have chosen the Double Cross Antenna, we have bought the different components in order to build it. We passed 10 hours to build the antenna and then we placed it on the roof of the lab building.
Finally, we studied two different solution to receive and decode our signal, one with WXtoImg and the other with Labview.
We were able to lead this project from the study of the APT transmission chain to receiving process. The building of the antenna was a main step of our project and was the more interesting part. It allowed us to understand more clearly how the antenna works, particularly the polarization.
The improvements that we could have done are about the correction of the Doppler effect. We could used a Digital Phase Locked Loop to remove this effect. One other improvement it is about the using of a directional antenna with a tracking system to have a better signal at the reception and thus a better quality for the images.
- http://www.geo-web.org.uk/ “A tool for evaluatiing APT antenna performance”