Dear all,

We got a glimpse of S-NET 4 tonight!

Sadly we were unable to record a relevant number of data points.

We saw the target swooshing through the screen with a time bias setting of -170 to -200 ms.
The real time bias must be less than -200 ms.

Best
Jens

I've also added Compass-M3 for comparison.

Best Jens

Dear all, Randall,

Toshi forwarded the original post to Zhang, who replied to say that the MS1/2 (I assume all 3rd generation Beidou) predictions are done at a different institute and he would pass on the information. He did also say though that they have raised this several times before. As you say Randall, it may well be that they are more difficult to do good cpfs for because they aren't officially active yet, so the quantity of ground station data will be less. But surely this makes them poor candidates for highest priority in the LARGE campaign? Unless someone is going to use the SLR to improve the predictions, but I don't know if this is happening? Can we be explicit in saying to the mission people that the ILRS performance on their satellites (even in LARGE campaign) is currently limited by prediction quality and this is seriously impacting the work they can do with the final data set?

Best regards,

Rob

The predictions for COMPASS-MS1 and COMPASS-MS2 have been consistently poor since the start of their laser tracking operations. This is strange, for the COMPASS-M3 predictions are of the regular good quality we expect for this kind of satellite.

We are talking about time biases of seconds, plus up to hundreds of milliarcseconds cross-track offsets. This makes daytime tracking simply impossible, and requires substantial additional time and effort to obtain returns during night time operations.

COMPASS-MS1 has been recently included in the high priority list of the LARGE campaign. The intensive tracking requirements for this campaign are obviously harder to fulfill if the predictions are sub-standard. Two questions come to mind: 1) Why are predictions so poor for these objects? 2) When should we expect them to improve?

In the interim, perhaps it would be useful to include COMPASS-MS1 in the time bias prediction service run by Potsdam?

Hi

At the Graz station we are using a TRX-1500 ADS-B Receiver which includes a FLARM System.

https://www.air-avionics.com/?page_id=253
https://www.air-avionics.com/wp-content/themes/yootheme/cache/traffic_1-70910620.jpg

The data stream gives us the position of ADS-B equipped aircrafts as well as those with FLARM.

Cheers