skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Performance of the Polar Formatting Algorithm for SAR Image Formation on Wide Aperture Collections

Abstract

No abstract prepared.

Authors:
Publication Date:
Research Org.:
Sandia National Labs., Albuquerque, NM (US); Sandia National Labs., Livermore, CA (US)
Sponsoring Org.:
US Department of Energy (US)
OSTI Identifier:
765247
Report Number(s):
SAND2000-2531C
TRN: AH200103%%272
DOE Contract Number:
AC04-94AL85000
Resource Type:
Conference
Resource Relation:
Conference: IEEE Digital Signal Processing Workshop, Hunt, TX (US), 10/15/2000--10/18/2000; Other Information: PBD: 12 Oct 2000
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION; ALGORITHMS; RADAR; PERFORMANCE; IMAGE PROCESSING

Citation Formats

JAKOWATZ JR.,CHARLES V.. Performance of the Polar Formatting Algorithm for SAR Image Formation on Wide Aperture Collections. United States: N. p., 2000. Web.
JAKOWATZ JR.,CHARLES V.. Performance of the Polar Formatting Algorithm for SAR Image Formation on Wide Aperture Collections. United States.
JAKOWATZ JR.,CHARLES V.. 2000. "Performance of the Polar Formatting Algorithm for SAR Image Formation on Wide Aperture Collections". United States. doi:. https://www.osti.gov/servlets/purl/765247.
@article{osti_765247,
title = {Performance of the Polar Formatting Algorithm for SAR Image Formation on Wide Aperture Collections},
author = {JAKOWATZ JR.,CHARLES V.},
abstractNote = {No abstract prepared.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = 2000,
month =
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share:
  • No abstract prepared.
  • IFP V4.0 is the fourth generation of an extraordinarily powerful and flexible image formation processor for spotlight mode synthetic aperture radar. It has been successfully utilized in processing phase histories from numerous radars and has been instrumental in the development of many new capabilities for spotlight mode SAR. This document provides a brief history of the development of IFP, a full exposition of the signal processing steps involved, and a short user's manual for the software implementing this latest iteration.
  • Wavefront curvature defocus effects can occur in spotlight-mode SAR imagery when reconstructed via the well-known polar formatting algorithm (PFA) under certain scenarios that include imaging at close range, use of very low center frequency, and/or imaging of very large scenes. The range migration algorithm (RMA), also known as seismic migration, was developed to accommodate these wavefront curvature effects. However, the along-track upsampling of the phase history data required of the original version of range migration can in certain instances represent a major computational burden. A more recent version of migration processing, the Frequency Domain Replication and Downsampling (FReD) algorithm, obviatesmore » the need to upsample, and is accordingly more efficient. In this paper the authors demonstrate that the combination of traditional polar formatting with appropriate space-variant post-filtering for refocus can be as efficient or even more efficient than FReD under some imaging conditions, as demonstrated by the computer-simulated results in this paper. The post-filter can be pre-calculated from a theoretical derivation of the curvature effect. The conclusion is that the new polar formatting with post filtering algorithm (PF2) should be considered as a viable candidate for a spotlight-mode image formation processor when curvature effects are present.« less
  • Effects of image charges on beam halo formation and beam loss in small-aperture alternating-gradient focusing systems are studied analytically, computationally, and experimentally. Nonlinear image-charge fields result in chaotic particle motion and the ejection of particles from the beam core into a halo. Detailed chaotic particle motion and structure of the particle phase space is studied, and the beam loss rate is computed for a long transport channel. Image-charge effects are also studied for a short transport channel, and compared with the Neutralized Transport Experiment (NTX) at LBNL.
  • An acousto-optic processor which forms synthetic aperture radar images in real-time is described. It employs a space and time integrating architecture to perform the required two dimensional matched filtering operation as a sequence of one dimensional processes. The matched filtering in range is performed on each radar return pulse using the acousto-optic device. The azimuthal matched filtering is performed using a fixed reference mask and a charge-coupled device operating in the time delay and integrate mode. This fixed mask architecture has been modified to include a background subtraction capability to reduce the effects of unwanted bias terms on image quality.more » The effectiveness of this technique will be analyzed for two different time bandwidth product cases. SAR imagery formed using the real-time optical processor is also presented.« less