Differences between revisions 1 and 3 (spanning 2 versions)
Revision 1 as of 2016-09-01 03:16:00
Size: 952
Comment:
Revision 3 as of 2016-09-01 03:17:52
Size: 995
Comment:
Deletions are marked like this. Additions are marked like this.
Line 7: Line 7:
Assume a test array of 50 12x12 centimeter 2 watt thinsats, deployed from a 2U cubesat. Effective transmit power, perhaps 2 watts, effective dish area, 12 x 600 centimeters, making a steerable asymmetric beam 0.1 by 0.002 radians, EIRP 125 kW. From GEO (40,000 km path length), with a 2 meter tracking receive dish, that would deliver 20 picowatts to the receiver. Assuming kT = 0.05 eV = 8e-21 J at 600 K effecting noise temperature, and 5 kT per bit, that is 4e-20 W/bps, or 500 Mbps - more than a 50 MHz channel can support. Assume 100 Mbps downlink - plenty of bandwidth to return a lot of scientific information from the test array. Assume a test array of 50 12x12 centimeter 2 watt 5 gram thinsats (100 watts total power), deployed from a 2U cubesat. Effective transmit power, perhaps 2 watts, effective transmit antenna area, 12 x 600 centimeters, making a steerable asymmetric beam 0.1 by 0.002 radians, EIRP 125 kW. From GEO (40,000 km path length), with a 2 meter tracking receive dish, that would deliver 20 picowatts to the receiver. Assuming kT = 0.05 eV = 8e-21 J at 600 K effective noise temperature, and 5 kT per bit, that is 4e-20 W/bps, or 500 Mbps - more than a 50 MHz channel can support. Assume 100 Mbps downlink - plenty of bandwidth to return a lot of scientific information from the test array.

24 GHz Amateur Radio Band

for the first server sky experiments


The first server sky experiments may use the 1.2 centimeter ham bands, 24.00 to 25.05 GHz, using a global network of amateur radio operators for the ground stations.

Assume a test array of 50 12x12 centimeter 2 watt 5 gram thinsats (100 watts total power), deployed from a 2U cubesat. Effective transmit power, perhaps 2 watts, effective transmit antenna area, 12 x 600 centimeters, making a steerable asymmetric beam 0.1 by 0.002 radians, EIRP 125 kW. From GEO (40,000 km path length), with a 2 meter tracking receive dish, that would deliver 20 picowatts to the receiver. Assuming kT = 0.05 eV = 8e-21 J at 600 K effective noise temperature, and 5 kT per bit, that is 4e-20 W/bps, or 500 Mbps - more than a 50 MHz channel can support. Assume 100 Mbps downlink - plenty of bandwidth to return a lot of scientific information from the test array.

HamBand (last edited 2016-09-01 05:17:46 by KeithLofstrom)