Global phase unwrapping of interferograms
First Claim
1. A method of processing a wrapped phase array into an unwrapped phase array, the method comprising steps of:
- forming a twice unfolded array from the wrapped phase array and computing a first array, each element of the first array being based on a discrete Poisson difference equation;
processing the first array through a two dimensional FFT to form a second array;
scaling the second array by a scaling function to form a third array; and
processing the third array through an inverse two dimensional FFT to form the unwrapped phase array.
7 Assignments
0 Petitions
Accused Products
Abstract
An interferogram is an array of phases, often generated from the inverse tangent of a ratio of an imaginary component divided by a real component. The array is said to be a wrapped phase array when the phase angle is modulo between zero and 2π. A method of processing a wrapped phase array into an unwrapped phase array includes computing a first array from the wrapped phase array, each element of the first array being based on a discrete Poisson difference equation, processing the first array through a two dimensional FFT to form a second array, scaling the second array by a scaling function to form a third array, and processing the third array through an inverse two dimensional FFT to form the unwrapped phase array. The step of computing a first array includes forming a twice unfolded array from the wrapped phase array, computing a row difference array, an element in the row difference array being based on a difference between an element in a particular row in the twice unfolded array and an element in an adjacent row in the twice unfolded array, computing a column difference array, an element in the column difference array being based on a difference between an element in a particular column in the twice unfolded array and an element in an adjacent column in the twice unfolded array, computing a double row difference array, an element in the double row difference array being based on a difference between an element in the particular row in the row difference array and an element in an adjacent row in the row difference array, computing a double column difference array, an element in the double column difference array being based on a difference between an element in the particular column in the column difference array and an element in an adjacent column in the column difference array, and adding the double row difference array to the double column difference array element by element to form the first array.
-
Citations
12 Claims
-
1. A method of processing a wrapped phase array into an unwrapped phase array, the method comprising steps of:
-
forming a twice unfolded array from the wrapped phase array and computing a first array, each element of the first array being based on a discrete Poisson difference equation; processing the first array through a two dimensional FFT to form a second array; scaling the second array by a scaling function to form a third array; and processing the third array through an inverse two dimensional FFT to form the unwrapped phase array. - View Dependent Claims (2, 3, 4)
-
-
5. A computing machine comprising:
-
a processor; a first module to form a twice unfolded array and compute a first array from a wrapped phase array, each element of the first array being based on a discrete Poisson difference equation; a second module to process the first array through a two dimensional FFT to form a second array; a third module to scale the second array by a scaling function to form a third array; and a fourth module to process the third array through an inverse two dimensional FFT to form a unwrapped phase array. - View Dependent Claims (6, 7, 8)
-
-
9. A computer readable medium having stored thereon a plurality of modules for controlling a computer, the plurality of modules comprising:
-
a first module to control the processor to form a twice unfolded array and compute a first array from a wrapped phase array, each element of the first array being based on a discrete Poisson difference equation; a second module to control the procesor to process the first array through a two dimensional FFT to form a second array; a third module to control the processor to scale the second array by a scaling function to form a third array; and a fourth module to control the processor to process the third array through an inverse two dimensional FFT to form a unwrapped phase array. - View Dependent Claims (10, 11, 12)
-
Specification