Electrolab::Forum

j'espere ne pas être "hors sujet" il y a eu cette demande sur la liste HYPERFR
Bonjour,

Parmi les personnes actives en 70cm, est ce que certains d’entre vous pourrez écouter ce satellite pour aider ces étudiants ?

Merci pour eux

JJ F1EHN

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Hi Guys,

I hope this is not too inappropriate to ask a question completely unrelated to pulsars. Here is the background and my request:

We have been asked by a team at the university of Aachen to help them receiving data from a cubesat on S-band. This is a student project there. We are in the process of implementing a receiving chain on our 3m dish. The intention had been to start this in about 6 weeks from now.

The satellite had just been launched on the 22nd as secondary payload on a PSLV from India. Together with a whole bunch of other nano-satellites it seems that the satellite has been successfully released into orbit. The first step then was to receive the beacon in the 70cm band. However, in the first overpasses no signal was received. They have asked us for support also on 70cm reception.

Unfortunately we have no capability with our big dish to receive at 70cm, but I have promised to them to look for other options. So I am asking whether some of you guys have the capability and interest to look for a signal.



Here are the details:

The satellite is called Compass2 and has two purposes: One is to test thin film solar arrays, the other is to deploy a dragsail at the end of the mission to test fast de-orbiting. The primary communication link is on 70cm for downlink and on VHF for uplink. There is a secondary downlink at S-band for higher data rates. This will only work after the satellite has been de-tumbled (due to the directivity of the antenna) so it is not active at the moment.

The transmission frequency of the satellite is 437.3 MHz, modulation is AFSK AX.25 1200bd.

If you are interested and you can work with two line elements (TLE) for orbital data, here are the latest TLE:

QB50_DE04

1 19004U 19004A 17174.17985324 0.00000000 00000-0 00000-0 0 9997

2 19004 97.4471 233.9424 0009781 251.7546 329.5818 15.20764799 00006

If this something you are not familiar with, I can provide time, azimuth and elevation for your location for the overpasses.



Any help is appreciated.

Best regards

Wolfgang

Nan, pas d’erreur ! C'est bien ici !

On va jeter un œil de près... Je pensais le faire dans le week-end, mais je ne suis finalement pas passé au lab...

Ya

Pour essayer de répondre à la demande d'aide de l'université d'Aachen, j'ai préparé les TLE pour Compass2, envoyé en même temps que Robusta (reçu fort et clair hier soir à l'Electrolab).



Ce fichier se fait manger directement par Gpredict...

Bon... Ecoute attentive hier soir sur deux passage... On reçoit Robusta (lancé en même temps... Les TLE sont les mêmes) pleine gamelle, mais rien du tout à la fréquence de Compass2...

Optimiste je ne suis pas... :p

J'ai envoyé le report selon lequel "nada", et la réponse d'astropeiler (la team qui a demandé le coup de mail pour le compte de l'université d'Aachen) :

Hi Yannick,
Thank you very much for your report. This unfortunately is line with reports
from other observers: They do see Robusta but not Compass2.

Our original role was to support the Aachen university by reception of
S-Band transmission from this satellite. Because of the missing UHF signal
they requested us for support on 70cm as well. Since we do not have any 70cm
capability ourselves, we reached out to seek support from others.
The present hope is that the antenna did not deploy correctly so that a
signal (if any) would be very weak. There is support now from a station with
a 8.6m dish so if the satellite is sending its beacon signal at all we would
hope this station can receive it.

We have to see what comes out of it.
Thanks again for your support!
Wolfgang

Au passage, ils ont un joli jouet, ces gens :

https://astropeiler.de/