Method and apparatus for compensating for a parameter change in a synthetic aperture imaging system

• US 9,176,227 B2
• Filed: 06/28/2010
• Issued: 11/03/2015
• Est. Priority Date: 06/28/2010
• Status: Active Grant

• Current Assignee: Institut national d'optique
• Original Assignee: Institut national d'optique
• Inventors: Bergeron, Alain, Marchese, Linda
• Primary Examiner(s): Barker, Matthew M
• Application Number:
  US12/933,005
• Publication Number:
  US 20120218140A1
• Time in Patent Office: 1,954 Days
• US Class Current: 1/1
• CPC Class Codes: G01S 13/9005 with optical processing of the SAR signals
• CPC Class Codes: G01S 13/904 SAR modes
• CPC Class Codes: G01S 13/9054 Stripmap mode
• CPC Class Codes: G01S 15/8997 using synthetic aperture techniques
• CPC Class Codes: G01S 17/90 using synthetic aperture techniques
• CPC Class Codes: G01S 7/4004 of parts of a radar system
• CPC Class Codes: G02B 27/58 Optics for apodization or superresolution; Optical synthetic aperture systems
• CPC Class Codes: G03H 2001/046 Synthetic aperture
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction

Abstract

There is described a method for processing data generated by a synthetic aperture imaging system, comprising: receiving raw data representative of electromagnetic signals reflected by a target area to be imaged; receiving a parameter change for the synthetic aperture imaging system; digitally correcting the raw data in accordance with the parameter change, thereby compensating for the parameter change in order to obtain corrected data; and generating an image of the target area using the corrected data.

Claims

1. A method for processing data generated by a synthetic aperture imaging system, comprising:

receiving raw data representative of electromagnetic signals reflected by a target area to be imaged;

receiving a parameter change causing a variation of an interference pattern parameter for said synthetic aperture imaging system, said interference pattern parameter being one of a Fresnel zone plate focal length and a Fourier slice scaling parameter;

using a processing unit, digitally correcting said raw data in accordance with said parameter change, said correcting comprising determining a scaling factor using said parameter change and scaling said raw data in accordance with said scaling factor, thereby compensating for said parameter change in order to obtain corrected data; and

generating an image of said target area using said corrected data, said generating comprising;

generating an incident light;

modulating said incident light in accordance with said corrected data, thereby obtaining a modulated light; and

optically processing said modulated light, thereby obtaining an optical image of said target area.

2. The method as claimed in claim 1, further comprising detecting said optical image to obtain a digital image of said target area.

3. The method as claimed in claim 1, wherein said parameter change comprises a change of one of a pulse repetition frequency, a range sampling frequency, and a slant range distance.

4. The method as claimed in claim 1, wherein said receiving said raw data comprises receiving said raw data from one of a synthetic aperture radar system, a synthetic aperture lidar system, a synthetic aperture terahertz system, and a synthetic aperture infrared system.

5. A system for generating a synthetic aperture image of a target area, comprising:

a memory configured to store raw data representative of electromagnetic signals reflected by said target area and a parameter change causing a variation of an interference pattern parameter for said synthetic aperture imaging system, said interference pattern parameter comprising one of a Fresnel zone plate focal length and a Fourier slice scaling parameter;

a processing unit configured to determining a scaling factor using said parameter change and scaling said raw data in accordance with said scaling factor in order to compensate for said parameter change and obtain corrected data; and

an image generator configured to generate an image of said target area using said corrected data, said image generator comprising;

a light source configured to generate incident light;

a light modulator configured to moderate said incident light in accordance with said corrected data, thereby obtaining a modulated light; and

an optical processor configured to optically process said modulated light, thereby obtaining said image of said target area.

6. The system as claimed in claim 5, wherein said image generator further comprises an image sensor for detecting said optical image and generating a digital image of said target area.

7. The system as claimed in claim 5, wherein said parameter change comprises a change of one of a pulse repetition frequency, a range sampling frequency, and a slant range distance.

8. The system as claimed in claim 5, wherein said memory is configured to store said raw data generated by one of a synthetic aperture radar system, a synthetic aperture lidar system, a synthetic aperture terahertz system, and a synthetic aperture infrared system.