The book is not wrong, but it does present the concepts on LFM in a clunky manner and can be misleading. The book presents the analytical expression for the LFM spectrum, which is an approximation. It also plays with the plot views and most likely unwraps the phase angles, which is usually required to see the phases you expect.
Usually when you're ...
I believe you're correct, it's an issue with the overlap-add process. The code doesn't correctly calculate the triangular windows for lower pitches.
In short, the windows are too big.
It produces incorrect results for any pitch ratio below 1, such as 0.5 (one octave down).
The diagram below explains the issue as I understand it:
The big windows introduce so ...
You'd avoid having this problem by detecting whether FM is present before demodulating it.
The reason is simple: FM demodulation throws away a lot of the info that's still in the RF signal – most prominently, the actual received power – and that info is what you'd want to use to squelch.
That can (unless there's other types of transmissions than audio FM ...
Simple answer: Use LiveScan3D. Should be easy enough.
Longer answer: You are looking for a way to 'register' multiple point clouds. This is an extremely well studied problem in computer vision. In your case I would consider two scenarios:
Target-based (photogrammetry-like): Place some targets in the world such as markers (see OpenCV Aruco markers). Estimate ...
Hello NatanBackwards and welcome to DSP SE.
Your results seem valid to me but I would like to mention a couple of things here.
First of all, you have to keep in mind that due to the way "log-sine sweeps" work the part before the impulse response is comprised of the distortion components. Judging from the way you have handled the measurements I ...
I just implemented one VSDFT in Matlab and confirm what is said above. FFT makes uses of symmetries, but here you can't. Instead you should have a lot less number of points to compute, as if you had a quarter of the FFT to compute.