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Published byKathleen Daniels Modified over 8 years ago
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The effective isotropic radiated power from Rosetta (HGA in X-Band) is 57 dBW At Rosetta’s current distance (2.7AU), received power in air will be -225 dBW ESA’s New Norcia 35m station as a reference, and thanks to its 1000m 2 antenna collecting surface and gain of 68 dBi Rosetta’s weak signal is captured and results in a received power of -157 dBW – just 1.8 Femto-Watts. LNA is operated at -260 0 C Noise Floor kT equals -186 dBm/Hz TX power of Rosetta is 28 W using a antenna dish sized 1.8 m News Nov. 2014
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Rosetta is presently sending signals to the ground stations at about 28 Kbps X-Band 8.421 GHz. Noise is -142 dBm S/N RF = E b /N 0 = 15 dB Downlink telemetry commands 2 kbit/s, Instrument data 26 kbit/s with a square wave subcarrier of 260 kHz which is BPSK modulated Command telemetry: PM with a square wave subcarrier of 16 kHz which is BPSK modulated (high Doppler resistant) News Nov. 2014 100 kHz/Div ©Bertrand Pinel, setileague.org
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Effective isotropic radiated power at 7.18 GHz (X-Band) is 52 dBW New Horizons distance at Pluto is 5·10 12 m, received power in air is -250 dBW NASA’s 70m dish station as a reference, and thanks to its 3800m 2 antenna collecting surface and gain of 74 dBi New Horizons’s weak signal is captured and results in a received power of -176 dBW – just 0.05 Femto-Watts. LNA is operated at -260 0 C Noise Floor kT equals -186 dBm/Hz TX power of New Horizons is 12 W using a antenna dish sized 2 m (42 dBic) News July. 2015
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New Horizons is presently sending signals to the ground stations at about 4 Kbps X-Band 7.18 GHz. Noise is at -150 dBm S/N RF = E b /N 0 = 4 dB Signal rroundtrip time is 9 hours, Instrument data rate is 2 kbit/s (scalable down to 8 bit/s) Receiver bandwidth 1 kHz, Noise level is -156 dBm, Signal level is -146 dBm, SNR is ideally 10 dB (Coding Gain) Data is BPSK modulated on a sinusoidal subcarrier of 16 kHz Subcarrier is PM modulated on X-band residual carrier News July 2015
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