Share Email Print

Proceedings Paper

Phase closure and object reconstruction algorithm for Fourier telescopy applied to fast-moving targets
Author(s): Brett Spivey; James Stapp; David Sandler
Format Member Price Non-Member Price
PDF $14.40 $18.00
cover GOOD NEWS! Your organization subscribes to the SPIE Digital Library. You may be able to download this paper for free. Check Access

Paper Abstract

Fourier Telescopy (FT) is an active imaging method which interferes spatially diverse, frequency-encoded laser beams on a distant target, and records a time history of the reflected intensity measured by a single photodetector on a large receiver. FT has been studied extensively for imaging Geostationary objects, using high-energy pulsed lasers to project triplets of laser beams, by gradually stepping over time through the multitude of u,v-plane baselines required for accurate object reconstruction. Phase closure among the received triplets plays a key role in canceling out random atmospheric phase errors between laser beams. A new method has been devised to apply FT to rapidly moving targets, such as LEO space objects. In order to implement the thousands of baselines in a short engagement time, approximately 20 continuous-wave laser beams are simultaneously broadcast, and the baseline configurations are rapidly changed through a dynamic optical element. In order to eliminate unknown atmospheric errors, a new type of global phase closure has been developed, which allows image reconstruction from the time history of measured total reflected intensity, originating from the complex 20-beam interference patterns. In this paper, we summarize the new FT LEO method, and give a detailed derivation of the phase closure and image reconstruction algorithms that will lead to ultra-high resolution images of fast-moving space objects.

Paper Details

Date Published: 8 September 2006
PDF: 16 pages
Proc. SPIE 6307, Unconventional Imaging II, 630702 (8 September 2006); doi: 10.1117/12.682179
Show Author Affiliations
Brett Spivey, Quexta (United States)
James Stapp, Trex Enterprises Corp. (United States)
David Sandler, Trex Enterprises Corp. (United States)

Published in SPIE Proceedings Vol. 6307:
Unconventional Imaging II
Victor L. Gamiz; Paul S. Idell; Marija S. Strojnik, Editor(s)

© SPIE. Terms of Use
Back to Top