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Investigation of hard targets for calibration of a coherent doppler lidar system
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Anderson, Richard |
| Copyright Year | 1986 |
| Description | The bihemispherical reflectance has been measured for a diffuse gold surface the same as the coating on the integrating sphere, flowers of sulfur, sandblasted aluminum, and 120 grade aluminum oxide sandpaper. The sandpaper measurements indicate that materials with low reflectance cannot be measured until more sensitive detection techniques are found. The sphere had to be used without a detector baffle so an unusual geometry was needed that led to a loss of intensity. Further, it is estimated that some first-strike light entered the detector and the readings could be 1 to 1.5% too low. A limited number of normal incident directional-hemispherical reflectance measurements were made on aluminum and sandpaper. Several recommendations are made: (1) the proper baffle placement; (2) improve lock-in detection using a PAR lock-in amplifier or the heterodyne technique; (3) modification of the sphere so the sample may be mounted at the cell center on a graduate, rotatable table for measurement of directional-hemispherical reflectance; (4) the purchase of additional diffuse gold samples with coatings like the sphere; and (5) better laser temperature control to improve intensity stability. |
| File Size | 1067425 |
| Page Count | 32 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19870007311 |
| Archival Resource Key | ark:/13960/t4bp4zn4f |
| Language | English |
| Publisher Date | 1986-11-01 |
| Access Restriction | Open |
| Subject Keyword | Lasers And Masers Coherent Radar Metal Coatings Baffles Calibrating Backscattering Radar Detection Radar Targets Spheres Doppler Radar Optical Radar Reflectance Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
