Angle of arrival in 3D for AWR1843 BOOST radar

I am using AWR 1843 BOOST FMCW radar. I obtained the raw data and processed it to get the range doppler matrix. I am now trying to get the 3D point cloud using FFT. In my setup, the vertual antennas 1-4,9-12 correspond to the azimuth and antennas 5,6,7,8 correspond to the elevation. If i perform the fft along the third dimention for antennas 1-4,9-12 I get the 2D point cloud with azimuth information. This is stored in theta

Now to get the elevation angle, I have the range doppler matrix arranged in the following format

elevation_fft = cat(3,RDmap_cmpx(:,:,5),RDmap_cmpx(:,:,6),RDmap_cmpx(:,:,7),RDmap_cmpx(:,:,8),RDmap_cmpx(:,:,3),RDmap_cmpx(:,:,4),RDmap_cmpx(:,:,9),RDmap_cmpx(:,:,10));

i perform fft over elevation_fft whose size is 512*64*8 across the this dimention and convert to cartesian coordinates using this formula

xdata(i) = r_vect*cos(deg2rad(theta))*cos(deg2rad(phi));

ydata(i) = -r_vect*cos(deg2rad(theta))*sin(deg2rad(phi));

zdata(i) = r_vect*sin(deg2rad(theta));

I get meaning less elevation point cloud when I plot this.

How do I consider the antenna order for elevation fft? What am I doing wrong here?

Answer 1

[Supraja]

Hello Praanesh,

I understand that you want to perform FFT using an elevation angle but the output you are observing is not as expected.

To debug your code, you can use 'Range-angle response' function of an FFT. This will provide the response of the angle you are giving as an input and will help you to debug your code.

Please find the documentation link of the function below:

https://in.mathworks.com/help/phased/ref/phased.rangeangleresponse-system-object.html

Thanks!