Accession Number:

ADA028586

Title:

Wavefront Estimation for Adaptive Optics.

Descriptive Note:

Interim rept. no. 1, Jul 74-Sep 75,

Corporate Author:

FRANK J SEILER RESEARCH LAB UNITED STATES AIR FORCE ACADEMY COLO

Personal Author(s):

Report Date:

1976-07-01

Pagination or Media Count:

60.0

Abstract:

The first step in obtaining maximum irradiance on an object or for image compensation is that of wavefront diagnostics. This report considers the use of estimation theory techniques in order to diagnose the required wavefront changes for wavefront control. The control elements can be the adjustment of the focal length of a Cassegrain telescope by changing the distance between the primary and secondary mirrors, the control of a tilt mirror, and the control of a deformable mirror. This paper considers the use of an extended Kalman filter in order to obtain estimates of the diffraction focus position and the target range from a measurement of the reflected irradiance. The measurement is obtained by a detector with a wide field of view located near the location of the Cassegrain telescope. As the detector gain of an irradiance measurement is a function of certain target characteristics and as these characteristics may only be nominally known, a scale factor error in the detector gain is introduced and estimated. The laser system considered transmits a focused, truncated Gaussian beam at 10.6 micrometer wavelength. However the filter can be used for other wavelengths.

Subject Categories:

  • Optical Detection and Detectors
  • Infrared Detection and Detectors
  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE