Method for self-calibrated sub-aperture stitching for surface figure measurement
First Claim
1. A method for synthesizing a full-aperture numerical data map of a test surface of an object from a plurality of overlapping sub-aperture data maps of said surface, comprising the steps of:
- a) collecting said plurality of sub-aperture numerical data maps of said surface from a plurality of regions of said surface, at least a portion of each such map overlapping a portion of at least one adjacent map to create a region of overlapping data;
b) projecting said plurality of overlapping data maps onto a global coordinate system with a nominal distortion map;
c) selecting a plurality of error compensators from one of two groups consisting of free compensators having free amplitude range and interlocked compensators having identical constrained amplitudes to compensate for stitching errors in said overlapping data regions; and
d) simultaneously minimizing mismatch of data from each of said data maps in said overlapping regions through linear combinations of said compensators.
11 Assignments
0 Petitions
Accused Products
Abstract
A method for accurately synthesizing a full-aperture data map from a series of overlapped sub-aperture data maps. In addition to conventional alignment uncertainties, a generalized compensation framework corrects a variety of errors, including compensators that are independent in each sub-aperture. Another class of compensators (interlocked) include coefficients that are the same across all the sub-apertures. A constrained least-squares optimization routine maximizes data consistency in sub-aperture overlap regions. The stitching algorithm includes constraints representative of the accuracies of the hardware to ensure that the results are within meaningful bounds. The constraints also enable the computation of estimates of uncertainties in the final results. The method therefore automatically calibrates the system, provides a full-aperture surface map, and an estimate of residual uncertainties. Therefore, larger surfaces can be tested with greater departures from a best-fit sphere to greater accuracy than was possible in the prior art.
71 Citations
11 Claims
-
1. A method for synthesizing a full-aperture numerical data map of a test surface of an object from a plurality of overlapping sub-aperture data maps of said surface, comprising the steps of:
-
a) collecting said plurality of sub-aperture numerical data maps of said surface from a plurality of regions of said surface, at least a portion of each such map overlapping a portion of at least one adjacent map to create a region of overlapping data;
b) projecting said plurality of overlapping data maps onto a global coordinate system with a nominal distortion map;
c) selecting a plurality of error compensators from one of two groups consisting of free compensators having free amplitude range and interlocked compensators having identical constrained amplitudes to compensate for stitching errors in said overlapping data regions; and
d) simultaneously minimizing mismatch of data from each of said data maps in said overlapping regions through linear combinations of said compensators. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
-
Specification