An amplitude modulated laser system for distance and displacement measurementA laser distance and displacement measurement system is being developed to monitor small displacements in large space structures for strain analysis and structural control. The reflected laser beam is focused on a detector and the detected signal is mixed with the reference. Small displacements are indicated by a change in modulation frequency which is adjusted to maintain quadrature between the received signal and the reference signal from the voltage-controlled oscillator in a phase-locked loop. Measurement of absolute distance is accomplished by sweeping the modulation frequency from a quadrature lock point to an adjacent lock point.
Document ID
19880025586
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Rogowski, Robert S. (NASA Langley Research Center Hampton, VA, United States)
Heyman, Joseph S. (NASA Langley Research Center Hampton, VA, United States)
Holben, Milford S., Jr. (PRC Kentron, Inc. Hampton, VA, United States)