Using the information on the following pages, calculate the link margin for the

ID: 115525 • Letter: U

Question

Using the information on the following pages, calculate the link margin for the ACE downlink (telemetry sent from the spacecraft down to the DSN 26m antenna) at its operational orbit.

General Information

•Spacecraft Range: 1.7x106 km

•Molecular Absorption: 0.2 dB

•Rain Attenuation: 0.1 dB

•Polarization Loss: 0.2 dB

•Implementation Loss: -2.0 dB

•Acceptable Bit Error Rate: 10-7

DSN 26m Antenna Information

•Minimum Elevation Angle: 10°

•Antenna Gain: 52.3 dB

•Pointing Loss: 0.1 dB

•Receiver Loss: 0.0 dB

•Total Noise Temperature: 161 K

ACE Spacecraft Information

•Modulation: BPSK

•Encoding:

•RS (255,223)

•Convolutional (1/2,7)

•Transmit Power: 6.0 W

•Transmit Frequency: 2.25 GHz

•Antenna Gain: 19.0 dB

•Antenna Line Loss: 0.7 dB

•Transmission Rate: 87.6 kb/s

Explanation / Answer

the information on the following pages, calculate the link margin for the ACE downlink (telemetry sent from the spacecraft down to the DSN 26m antenna) at its operational orbit.