Development of Prototype Optical Convolution Airspeed Sensor.
Abstract
This report describes the continued development of the Optical Convolution Airspeed Indicator. This relatively inexpensive instrument measures true airspeed by projecting a shadowgraph image of the wake from a small heater onto grating and measuring the ripple frequency of the turbulence crossing the grating. Measurements were made on the structure of the turbulent wake so that the heater size and grating can be optimized. A new type of signal processor, called a correlation discriminator, was developed to measure the frequency of the signal in the presence of a large amount of noise. An active heater protection circuit was built to prevent it from burning out when there is no air flow. The effects of environmental conditions on the sensor were examined and they can all be met, although the effects of rain and icing require further study. A new improved Prototype Mark 2 was builtAnd tested. There were significant changes in reading at angles of attack and sideslip above 10 to 15 deg.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1977
- Accession Number
- ADA039469
Entities
People
- Michael J. Rudd
Organizations
- BBN Technologies