High dynamic range ranging interferometer

A system, comprising:

• a set of active components, including:
• a light source, wherein the light source generates light of at least a first wavelength;
• a frequency comb generator, wherein the frequency comb generator outputs light at a plurality of frequencies, wherein each frequency of the plurality of frequencies of the light output by the frequency comb generator is spaced apart from an adjacent one of the frequencies of the light output by the frequency comb generator by a same amount, and wherein the same amount is 100 MHz;
• and
• a plurality of detectors;
• and
• a set of passive components, including:
• a reflector, wherein light from the light source is reflected by the reflector, mixed with at least a first signal from the frequency comb generator, and detected by the plurality of detectors to measure a frequency shift between the light as output by the light source and the light as reflected by the reflector.

A system, comprising:

• an interferometer, including:
• a laser light source;
• a frequency comb generator;
• an optical assembly;
• a polarizing beam splitter;
• and
• a non-polarizing beam splitter, wherein the laser light source outputs light at a first frequency, wherein the light output by the laser light source is directed to the polarizing beam splitter, wherein the optical assembly is located to receive light that exits the polarizing beam splitter, wherein the optical assembly forms a probe laser beam, wherein the optical assembly directs light in a return signal to the polarizing beam splitter, wherein the non-polarizing beam splitter is located to receive light in the return signal that exits the polarizing beam splitter, wherein the frequency comb generator is located to provide light at a plurality of reference frequencies to the non-polarizing beam splitter, and wherein heterodyne signals are produced at the non-polarizing beam splitter by combining the return signal with the light at the plurality of reference frequencies.

A method of measuring a relative velocity between platforms, comprising:

• sending a probe laser beam from a primary platform to a plurality of secondary platforms;
• receiving a frequency shifted version of the probe laser beam as a return signal from each of the plurality of secondary platforms at the primary platform;
• mixing the return signals with reference signals from a frequency comb generator to produce heterodyne signals, wherein the reference signals include a plurality of equally spaced reference signals;
• and
• determining a relative velocity of the platforms from a measured frequency shift using the heterodyne signals, wherein a frequency shifted version of the probe laser beam is received as a return signal from the plurality of secondary platforms simultaneously, wherein a first relative velocity between the primary platform and a first secondary platform is determined, and wherein a second relative velocity between the primary platform and a second secondary platform is determined.

A method of measuring a relative velocity between platforms, comprising:

• sending a probe laser beam from a primary platform to a secondary platform;
• receiving a frequency shifted version of the probe laser beam as a return signal from the secondary platform at the primary platform;
• mixing the return signal with reference signals from a frequency comb generator to produce a heterodyne signal, wherein the reference signals include a plurality of equally spaced reference signals;
• and
• determining a relative velocity of the platforms from a measured frequency shift using the heterodyne signal, wherein the frequency shift is measured using IQ detection.