Doppler correlators are configured to receive samples of a signal sampled based on a frequency. Each Doppler correlator includes successive butterfly elements. Each butterfly element includes cross-coupled first and second branches that include a sample delay that doubles for each successive butterfly element, and a sample inversion selectively placed in one of the first and second branches to encode into the successive butterfly elements of each Doppler correlator the same code sequence. Each Doppler correlator is configured with a respective phase rotation that varies across the Doppler correlators. Each Doppler correlator is configured to correlate the samples against the code sequence and apply the respective phase rotation to the samples as the samples are shifted through the successive butterfly elements, to produce respective correlation results from each Doppler correlator centered on a respective frequency offset from the frequency that varies across the Doppler correlators based on the phase rotations.