A system including one or more waveguides to receive a first returned reflection having a first lag angle and generate a first waveguide signal, receive a second returned reflection having a second lag angle different from the first lag angle, and generate a second waveguide signal. The system includes one or more photodetectors to generate a first output signal within a first frequency range, and generate, based on the second waveguide signal and a second LO signal, a second output signal within a second frequency range. The system includes an optical frequency shifter (OFS) to shift a frequency of the second LO signal to cause the second output signal to shift from within the second frequency range to within the first frequency range to generate a shifted signal. The system includes a processor to receive the shifted signal to produce one or more points in a point set.