working with angles and wraparound

Hi,

I have an antenna (the black dot) which is receiving pointing commands and sends pointing report.

Also I have a moving object around the antenna (the red line).

I'd like to compare the analytical analysis with the command and the report.

the issue is that when I cross from 360 to 0 I'll have a "spike" on the delta graph (of the command-report).

How to overcome the issue so that the transition would be smooth?

[Stephen23]

https://www.mathworks.com/help/matlab/ref/unwrap.html

Answer 1

[Pramil]

To overcome the issue of a "spike" in the delta graph when crossing from 360 to 0 degrees, you can use the concept of angular wrapping or circular arithmetic. This involves adjusting the values to ensure a smooth transition when crossing the 360-degree mark.

Here's an example of how you can implement angular wrapping in MATLAB:

% Generate sample data
command = [355, 358, 2, 5, 358, 1, 3, 6, 359, 2, 4, 357];
report = [354, 357, 3, 6, 357, 0, 2, 5, 358, 1, 3, 356];

% Convert the angles to the range [0, 360)
command_wrapped = mod(command, 360);
report_wrapped = mod(report, 360);

% Calculate the delta between command and report
delta = mod(report_wrapped - command_wrapped, 360);

% Plot the delta graph
plot(delta);
xlabel('Sample');
ylabel('Delta');
title('Command-Report Delta');

[michael]

Your example is not good. in the delta you shall have in the first place difference of 1, rather than 359 degress

Also, put in report [354 357 359 ...]

This is more realistis scenario - the difference is