Practical results
More than 300+ passes of satellites with different modulations have been received at the International Space University (ISU) Ground Station. Those included:
- FUNCUBE-1
- GOMX-1
- RAMSAT
- BOBCAT-1
- NAYIF-1
It needs to be said that not all satellites were properly operating. In fact, for the commercial flight-proved demonstration only two satellites were selected - FUNCUBE-1 and NAYIF-1. At the moment of writing of this report, RAMSAT and BOBCAT-1 are under integration, and UNISAT-6 and GOMX-1 seem to be malfunctioning (despite still being in orbit). They seem to be sending the telemetry, but almost every transmission is corrupted, which was confirmed by comparing it with observations of other people.
It was possible to compare the ISU GS performance with other ground stations. For this purpose, the SatNOGS platform has been used. SatNOGS is an open-source network, where radio stations/amateurs from all over the world track satellites and share their results. These results are publicly available through the web platform, so it was an opportunity to compare to see where the ISU GS has advantages and where it should be improved. Different parameters were estimated for FUNCUBE-1 and NAYIF-1 (signal decoding error rate, amount of packets received, minimal elevation angle for tracking). The main outcome of this is that from the point of practical application, the ISU Ground Station is one of the most powerful ground stations among the ones presented on SatNOGS. Hard to realize, but for almost all the parameters specified above, the ISU GS is an absolute leader. For example, for the average elevation of 50 degrees, the biggest amount of packets received for FUNCUBE-1 was 126, while the ISU GS usually do with ~145. The other aspect was a consistency of data received, and we may see from the figure below that for the whole pass approximately 11 minutes long all packets were properly received. Sometimes one or two are missed, which is still a very good result.
The monitoring of the ground segment is also very important - without ground segment anything else is impossible. For example, to ensure that the antenna subsystem is operating properly on the ISU GS side, an additional widget was created to display relevant antenna positions.
Other widgets are used to monitor the state of the ground station, the number of satellites tracked (for each frequency band), the number of preempted satellites, and other metrics:
