Abstract: A laser sensor system comprising a laser beam generator, a corrective optical device, an interference system, a detection system, and an analyzer. The laser beam generator is configured to emit a laser beam on a path from an aircraft. The corrective optical device is positioned in the path of the laser beam. The corrective optical device reduces distortion from the laser beam from passing through a turbulent air. The interference system is configured to interfere a backscatter light with a reference light to form an interfered light having a power in response to receiving the backscatter light. The detection system is configured to measure a set of characteristics for the interfered light. The analyzer is configured to determine a set of parameters for the aircraft using the set of characteristics.

Abstract: A method for detecting a speed of an aircraft. A first backscatter light generated in response to emitting a first laser beam having a first wavelength is received. A first beat frequency for a first interfered light generated by interfering the first backscatter light and a first reference light is measured. A second backscatter light generated in response to emitting a second laser beam having a second wavelength is received. A second beat frequency for a second interfered light generated by interfering the second backscatter light with a second reference light derived is measured. The speed of the aircraft is determined using the first beat frequency in response a power of the first backscatter light being greater than a threshold and using the second beat frequency is determined in response to the power of the first backscatter light not being greater than the threshold.

Abstract: A method, apparatus, and system detect a speed of a vehicle. Laser beams are emitted into an atmosphere from the vehicle. The laser beams are emitted in different directions from the vehicle. Sets of backscatter light are generated in response to transmitting the laser beams into the atmosphere from the vehicle. The sets of backscatter light have frequency shifts relative to the frequency of the laser beams. A set of beat frequencies from interfering the sets of backscatter light with each other is measure. The speed of the vehicle is determined using the set of beat frequencies.

Abstract: A method, apparatus, and system detects a speed of a vehicle. A backscatter light generated in response to transmitting a laser beam into an atmosphere during movement of the vehicle is received. A first beat frequency from interfering a first portion of the backscatter light with a reference light derived from the laser beam is measured. A time delay is introduced to a second portion of the backscatter light to form a time delayed backscatter light. A second beat frequency from interfering the time delayed backscatter light with the reference light is measured. The second beat frequency is time delayed from the first beat frequency. A difference between the first beat frequency and the second beat frequency is determined. The speed of the vehicle using the difference between the first beat frequency and the second beat frequency is determined.