Doppler speedometer

A system for determining and indicating the speed of a vehicle traveling through a medium with respect to the ground over which the vehicle is traveling, said system including,

• a power supply,
• generator means driven by said power supply for generating a carrier signal having predetermined characteristics,
• transmitter means for transmitting said carrier signal in a beam at a predetermined angle from said vehicle toward said ground,
• receiver means for receiving said carrier signal reflected from said ground, said carrier signal characteristics being changed to provide a spectrum of frequencies,
• means for determining a characteristic of the power spectrum of said spectrum of frequencies,
• means for analyzing said power spectrum characteristic for determining the value of said power spectrum characteristic for providing a driving output proportional to the average value of said power spectrum characteristic, and
• indicator means driven by said driving output and calibrated in speed for indicating the speed of said vehicle.

A device for determining the velocity of a vehicle with respect to ground, said vehicle suspended in a medium over said ground, said device including

• means for generating a continuous signal of predetermined characteristics,
• means for transmitting said continuous signal from said vehicle at a predetermined angle toward said ground,
• means for receiving said continuous signal reflected from said ground, said reflected signal including a spectrum of frequencies, having characteristics which are proportional to the velocity of said vehicle with respect to said ground,
• means for detecting said characteristics of said spectrum,
• means for generating an output, the value of which is proportional to said characteristics of said spectrum and
• indicator means responsive to said output for indicating velocity of said vehicle.

A device for determining velocity of a vehicle with respect to ground said vehicle traveling in water over said ground, said device including

• means for generating a carrier signal in the ultrasonic range of predetermined frequency and amplitude,
• means for transmitting said carrier signal from said vehicle in a beam having predetermined width, the center of said beam being substantially perpendicular to the direction of travel of said vehicle in said water and being directed at said ground,
• means for receiving said carrier signal reflected from said ground, said reflected signal including reflection characteristics including a spectrum of frequencies, said spectrum having characteristics substantially proportional to the velocity of said vehicle with respect to said ground,
• means for detecting said spectrum of frequencies,
• means for generating an output having a value proportional to said characteristics of said spectrum, and
• indicator means responsive to said output and calibrated in velocity for indicating velocity of said vehicle.

A device for determining the velocity of a vehicle with respect to the ground over which said vehicle is traveling, said vehicle suspended in a medium over said ground, said device including

• means for generating a continuous signal of predetermined frequency,
• means for transmitting said continuous signal from said vehicle in a beam having width, the center of which is substantially perpendicular to the line of travel of said vehicle, said beam being directed toward the ground,
• means for receiving said continuous signal reflected from said ground, said reflected signal including a spectrum of frequencies having a power spectrum being proportional to the velocity of said vehicle with respect to said ground,
• means for detecting the standard deviation of said power spectrum,
• means for generating an output the value of which is proportional to said standard deviation of said power spectrum, and
• indicator means responsive to said output for indicating the velocity of said vehicle.