Voyager link analysis
We use the link tools to analyze the Voyager communication links. We make a lot of assumptions including noise temperatures and we ignore other losses such as atmosphere. This demo creates a latex table.
------------------------------------------------------------------------ See also: Constant, LossFreeSpace, AntennaGain, DisplayLatexTable, CreateLatexTable ------------------------------------------------------------------------
Contents
%-------------------------------------------------------------------------- % Copyright (c) 2020 Princeton Satellite Systems, Inc. % All rights reserved. %-------------------------------------------------------------------------- % Since 2020.1 %--------------------------------------------------------------------------
Inputs
clear d s % X-band f = 8.4; pT = 23; % transmit power, W % Distance - Voyager, March, 2020 d = 148.6*Constant('au'); % Distance loss lD = LossFreeSpace( f, d );
Antenna properties
dT = 3.7; % diameter transmit dish, m dR = 70; % diameter receive dish, m aT = pi*(dT/2)^2; % area, m^2 aR = pi*(dR/2)^2; % area, m^2 d = AntennaGain; % Get defaults d.area = pi*(dR/2)^2; % set area gAR = AntennaGain( d, f ); d.area = pi*(dT/2)^2; gAT = AntennaGain( d, f ); % Gain from power gPT = 10*log10(pT); % Received power pR = gPT + gAT + gAR - lD; pRw = 10^(pR/10); % Watts
Data rates
t = 290; % temperature, K k = 1.38e-23; % Boltzmann's constant, J/K % Compute signal to noise ratios for both high and low data rates dRL = 160; % low data rate, bps b = dRL/1.5; % Assume QPSK sNL = 10*log10(pRw/(k*t*b)); dRH = 2.8e3; % high data rate, bps b = dRH/1.5; % Assume QPSK sNH = 10*log10(pRw/(k*t*b));
Output
k = 1;
s{k,1} = 'Loss Free Space'; s{k,2} = sprintf('%5.1f dB',lD); k = k + 1;
s{k,1} = 'Gain Receive Antenna'; s{k,2} = sprintf('%5.1f dB',gAR); k = k + 1;
s{k,1} = 'Gain Transmit Antenna'; s{k,2} = sprintf('%5.1f dB',gAT); k = k + 1;
s{k,1} = 'Gain Power'; s{k,2} = sprintf('%5.1f dB',gPT); k = k + 1;
s{k,1} = 'Low Data Rate'; s{k,2} = sprintf('%5.0f bps',dRL); k = k + 1;
s{k,1} = 'High Data Rate'; s{k,2} = sprintf('%5.0f bps',dRH); k = k + 1;
s{k,1} = 'Noise Temperature'; s{k,2} = sprintf('%5.0f deg-K',t); k = k + 1;
s{k,1} = 'S/N Low Data Rate'; s{k,2} = sprintf('%5.1f dB',sNL); k = k + 1;
s{k,1} = 'S/N High Data Rate'; s{k,2} = sprintf('%5.1f dB',sNH);
DisplayLatexTable(s)
CreateLatexTable(s,'VoyagerLink')
%--------------------------------------
Loss Free Space 317.9 dB
Gain Receive Antenna 73.7 dB
Gain Transmit Antenna 48.2 dB
Gain Power 13.6 dB
Low Data Rate 160 bps
High Data Rate 2800 bps
Noise Temperature 290 deg-K
S/N Low Data Rate 1.3 dB
S/N High Data Rate -11.1 dB