Positive and negative in old astra footprints

[Pride Of Cucamonga]

Hi, what's the meaning of the positive and negative in the old astra footprints? e.g. Astra 1E 19E - SatsUK
I assume these are the same as mode 1 and mode 2 on Astra 1A - see Astra 1A (now in junk orbit) - SatsUK

How did the tech change so that the current generation of satellites just have a single footprint?

thanks

 

[Channel Hopper]

You are confusing polarisation ( H/V ) with polarity ( + / -)

Stai confondendo la polarizzazione con la polarità , penso (credo)

 

[Pride Of Cucamonga]

You are confusing polarisation ( H/V ) with polarity ( + / -)

Stai confondendo la polarizzazione con la polarità

just trying to understand it! i get the H/V difference, but don't understand the +/-

 

[Channel Hopper]

Ah, now I see.

Forget the earlier post. It might be best and worst case downlink power

 

[Pride Of Cucamonga]

Ah, now I see.

Forget the earlier post. It might be best and worst case downlink power

Like as in good or bad weather?

 

[Channel Hopper]

Like as in good or bad weather?

Possiby, more likely the levels associated with the station keeping and lifecycle of the satellite.

 

[Captain Jack]

Huh... I always assumed that they were just different footprints!

 

[Pride Of Cucamonga]

Possiby, more likely the levels associated with the station keeping and lifecycle of the satellite.

I don't think it is this actually. if you look at Astra 1E, the transponders alternate EV1, EH1, EV2, EH2 etc see https://web.archive.org/web/20000818071114/http://www.lyngsat.com/astra1e.shtml

 

[Channel Hopper]

I don't think it is this actually. if you look at Astra 1E, the transponders alternate EV1, EH1, EV2, EH2 etc see Lyngemark Satellite Chart: Astra 1E at 19,2°E

The Ev1/2 and Eh1/2 look rather similar on your link
So, have you answered your own question to your satisfaction ?

 

[Pride Of Cucamonga]

The Ev1/2 and Eh1/2 look rather similar on your link
So, have you answered your own question to your satisfaction ?

Mode 1 and 2 on Astra 1A were a bit different - see Astra 1A (now in junk orbit) - SatsUK. Seems like over time the difference narrowed. Maybe there is still a 1 and 2 (AKA positive and negative?), but SES etc just don't publish it. Would still like to know what it all means.

 

[hvdh]

My thought always was, the dish at the satellite had two transmitter probes next to each other, resulting in these slightly different footprints. Maybe at the time, there was a reason (hardware) not to combine all transponders into one probe.