Centroid approach for estimating modulation peak in broad-bandwi

Details Centroid approach for estimating modulation peak in broad-bandwi Centroid approach for estimating modulation peak in broad-bandwi

1995-05-19

1997-05-27

Gonzalez, Frank

Optics: measuring and testing

By dispersed light spectroscopy

Utilizing a spectrometer

356357, 356360, G01B 1100

Patent

active

056337159

ABSTRACT:
A broad-bandwidth interferometric system that produces irradiance signals at multiple vertical-scanning positions as a function of optical path differences between a test and a reference surface. The effective peak of the envelope defined by the modulation component of the irradiance signal is estimated by finding the scanning position corresponding to the centroid of a function substantially equal to the square of the first-order derivative of the measured irradiance. The surface height at each pixel is determined directly from digital irradiance signals, thereby greatly reducing the data-processing steps and associated costs taught by the prior art and correspondingly simplifying the hardware requirements of the system for rapid on-line display of height measurements. The approach is free of the ambiguities inherent in multi-peak modulation functions, thereby producing surface maps with reduced artifacts. This improved technique produces results otherwise comparable with those obtained by standard techniques and requires no dedicated hardware for rapid on-line applications.

REFERENCES:
patent: 4340306 (1982-07-01), Balasubramanian
patent: 4387994 (1983-06-01), Balasubramanian
patent: 4670646 (1987-06-01), Spivey
patent: 4690562 (1987-09-01), Davies et al.
patent: 5204734 (1993-04-01), Cohen et al.
patent: 5341213 (1994-08-01), Giroux
patent: 5516608 (1996-05-01), Hobbs et al.
Davidson et al., "First Results of a Product . . . , " SPIE. vol. 921, 1988, pp. 100-114.
Dresel et al., "Three-Dimensional Sensing . . . , " Applied Optics, vol. 31, No. 7, Mar. 1, 1992, pp. 919-925.
Danielson et al., "Absolute Optical Ranging . . . , " Applied Optics, vol. 30, No. 21, Jul. 20, 1991, pp. 2975-2979.
De Groot et al., "Three-Dimensional Imaging . . . , " Optics Letters, vol. 18, No. 17, Sep. 1, 1993, pp. 1462-1464.
Kino et al., "Mirau Correlation Microscope," Applied Optics, vol. 29, No. 26, Sep. 10, 1990 pp. 3775-3783.
Caber et al., "A New Interferometric . . . , " SPIE, vol. 2088, 195-203, 1993.

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