Best way to do accurate amplitude measurements using FFT To do accurate amplitude measurements on an digital radar receiver, I am searching for the best method to get the amplitude out of a FFT. The signal is windowed using a Blackman window.
So far I'm only looking for the best way to reduce scalloping loss. I'm already in the frequency domain and want to find the real peak of the FFT spectrum. I already  tried parabolic interpolation, but this gives errors if the signal is near the noise level.
What is the best way to reduce scalloping loss errors without using a flattop window?
You can interpolate using the transform of your chosen window function as the interpolation kernel (similar to Sinc reconstruction), and then use successive approximation to find the peak of the interpolated spectrum.
Pre-constructing a polyphase table using an extremely oversampled transform of your chosen window might or might not assist in this computation.