Timeline for Characteristics of the modern satelite radio transmitters
Current License: CC BY-SA 3.0
12 events
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| Mar 13, 2017 at 12:40 | history | edited | Puffin | CC BY-SA 3.0 |
corrected spelling
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| Mar 13, 2017 at 11:08 | comment | added | user17550 | your equipment characteristics will always be a result of link budget calculations, not the other way around. The characteristics mean nothing without knowing how they were chosen. Your table is useless. | |
| Mar 13, 2017 at 10:57 | comment | added | Glinka | @MarcusMüller, it's not about public calculations, it's about equipment characteristics | |
| Mar 13, 2017 at 10:42 | comment | added | user17550 | You won't find many public calculations of link budgets. It's a topic covered in almost any digital communications textbook, and I'm sure there's plenty of literature pertaining to satcom link budgets, so stop trying to collect examples, start learning the theory. | |
| Mar 13, 2017 at 10:34 | comment | added | Glinka | @MarcusMüller, for now I can't even form a somewhat complete list of satellites operating in Ka range. | |
| Mar 13, 2017 at 10:33 | comment | added | Glinka | @MarcusMüller, but that's actually exactly what I need. I need to make an overview that includes that kind of table, methods of calculating link budget, some other stuff. And whilst other stuff are easily googleable, obtaining solid references to the current operating systems has presented a challenge. | |
| Mar 13, 2017 at 10:26 | answer | added | user17550 | timeline score: 5 | |
| Mar 13, 2017 at 10:20 | comment | added | user17550 | I don't think that table would be overly helpful. You just design that forward. You calculate how much power must reach the satellite, you calculate path loss, you define a receiver operation characteristic (ie. amount of outages you're willing to accept), you derive a security margin from that, this gives you amount of power you need to radiate, and based on your ability to be sure that your satellite is within the beam center, and your amplifier vs antenna cost tradeof, design an antenna/amplifier system.It really doesn't help much to know what others did for their very specific application. | |
| Mar 13, 2017 at 10:12 | comment | added | Glinka | @MarcusMüller, yes, thank you, this is helpful :) I was wondering though whether it's possible to find a table like <sat.name>, <sat. model>, <Tx band>, <Tx power> and so on for several (non-secret, non-military I guess) active satellite including LEO and GEO, observation and communication... For comparing and analysis purposes, since as you said the design may differ drastically. My searches have been fruitless yet. | |
| Mar 13, 2017 at 9:02 | comment | added | user17550 | For example, you've probably seen TV uplink dishes – which tend to be rather bulky, but that "pays" because they don't have to move, and every dB you get in gain has positive effect on your system performance. On the other hand, Inmarsat's upcoming Global Xpress satellite internet/telephony thing works in Ka band, and is aimed at antennas on commercial airplanes - certainly not 5m dishes; and those two applications are at least comparable in data rate. | |
| Mar 13, 2017 at 8:57 | comment | added | user17550 | That all really depends on what you transmit – a Gb/s video program bouquet link for a geostationary satellite will be fundamentally different from a Command&Control link that pushes a few bits per second to a satellite in LEO; so, this can't be universally answered; you must describe what the link does. Note that this is very close to what we comm engineers call Link Budget calculation. If I were you, I'd google that :) | |
| Mar 13, 2017 at 8:02 | history | asked | Glinka | CC BY-SA 3.0 |