Longley Rice propagation model and reciprocity

Question

Joel Johnson 2021-10-9

0
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1470451-longley-rice-propagation-model-and-reciprocity

评论： Joel Johnson 2021-10-14

Code snippet below seems to show that MATLAB's Longley-Rice propagation model may not always be reciprocal - is this correct? Thanks!

close all; clear all;
% A test to show that the Matlab LR functions don't seem to be reciprocal
pm   = propagationModel('longley-rice','AntennaPolarization','vertical');
freq =                  469e6;     % Tx freq (MHz) 
S1   = [39.420200,-82.875300];     % Lat/Lon of Site 1
S2   = [39.413000,-82.896111];     % Lat/Lon of Site 2
s1ht =                   1:50;     % Antenna height @ site 1
s2ht =                   2.08;     % Antenna height @ site 2
% Link from S1 to S2
tx   = txsite('Latitude',S1(1),'Longitude',S1(2),'AntennaHeight',s1ht,'TransmitterFrequency',freq);
rx   = rxsite('Latitude',S2(1),'Longitude',S2(2),'AntennaHeight',s2ht);
PL1  = pathloss(pm,rx,tx);
% Now reverse the link
tx   = txsite('Latitude',S2(1),'Longitude',S2(2),'AntennaHeight',s2ht,'TransmitterFrequency',freq);
rx   = rxsite('Latitude',S1(1),'Longitude',S1(2),'AntennaHeight',s1ht);
PL2  = pathloss(pm,rx,tx);
plot(PL1,s1ht,'linewidth',2); set(gca,'Xdir','Reverse'); set(gca,'Fontsize',20); xlabel('Path loss (dB)'); ylabel('Tx Antenna height (m)')
hold on
grid on
plot(PL2,s1ht,'x','linewidth',2);
legend('S1 to S2','S2 to S1')

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Joel Johnson 2021-10-9

I subsequently noticed that there is no difference in the two in R2021b so probably this got fixed somewhere between R2018 and R2021.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Tanmay Das 2021-10-14

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1470451-longley-rice-propagation-model-and-reciprocity#answer_808381

Hi,

As pointed out by Joel, the bug has been fixed in the future releases. So it is recommended to update the MATLAB version in order to leverage its full functionality.