Method for obtaining object-plane field from its two images

• US 8,362,947 B2
• Filed: 03/29/2011
• Issued: 01/29/2013
• Est. Priority Date: 03/29/2011
• Status: Expired due to Fees

• Current Assignee: Gorelik, Victor
• Original Assignee: Gorelik, Victor
• Inventors: Gorelik, Victor
• Primary Examiner(s): Keith, Jack W
• Assistant Examiner(s): BYTHROW, PETER M
• Application Number:
  US13/074,880
• Publication Number:
  US 20120249362A1
• Time in Patent Office: 672 Days
• Field of Search: 342/25.R, 342/25.A, 342/25.B, 342/25.C, 342/25.D, 342/25.E, 342/25.F, 342/179, 342/195, 342/196
• US Class Current: 342/179
• CPC Class Codes: G01S 13/90 using synthetic aperture techniques , e.g. synthetic aperture radar [SAR] techniques

Abstract

The invention provides a method for obtaining the object-plane field without a pure theoretical estimation or a direct experimental measurement of a point spread function (PSF) of an imaging system. Instead, at least two image-plane fields have to be recorded. It is essential that the resolutions of the system producing the images have to be quite different from each other. Although both PSFs of the system are unknown, the recording conditions have to be chosen so that the second PSF could be expressed via the first PSF. Two integral equations—(1) a convolution of the object-plane field with the first PSF and (2) a convolution of the object-plane field with the second PSF (expressed via the first PSF)—can be reduced to one functional equation in the Fourier space. The reverse Fourier transform of the solution of this equation is the object-plane field.

Claims

1. A method for obtaining the object-plane field S(x), running on a system that includes radar imaging system and a computer processor, comprising:

recording the first image I₁(x₀) as a data structure in the memory of the processor while the point spread function of the radar imaging system is described by an unknown function A₁(x₀−

x);

recording the second image I₂(x₀) as a data structure in the memory of the processor while the point spread function of the radar imaging system is described by an unknown function A₂(x₀−

x)=A₁[m(x₀−

x)], where m is in the range from 1.2 to 3;

using the processor for solving the system of the following two integral equations;

2. A method of the claim 1, where

the step of the recording the first image-plane field I₁(x₀) is executed by the radar imaging system with a ratio of the diameter of the reflector of the antenna to wavelength equal to r₁;

the step of the recording the second image-plane field I₂(x₀) is executed by the radar imaging system with a ratio of the diameter of the reflector of the antenna to wavelength equal to r₂=m r₁;

the step of the solving the system of two integral equations is executed by calculating the object-plane field S(x) as the reverse Fourier transform of the function