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Proceedings Paper

Time Delay And Integration Of Linear Pyroelectric Arrays
Author(s): S. C . Jain; S. S. Santara
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Paper Abstract

Time delay and integration (TDI) technique has been used in the imaging from moving platforms like satellite and remotely piloted vehicles (RPV) for improving resolution and signal to noise ratio. When the sensor is in motion with respect to the scene being imaged the TDI provides real advantage in the output signal to noise ratio (S/N). The improvement is proportional to the square root of the number of steps of integration. In the present paper authors present the improvement obtained in the S/N ratio by using time delay and integration in the pyroelectric linear imaging arrays. Scanning is performed with the help of a mechanical chopper. The signals from the alternate scans are of opposite polarity. The output of each scan from the array is digitised and stored in a memory. The output from the successive scans are delayed and added in phase. An inverter switch operating in synchronism with chopper inverts outputs of alternate scans and provides a sequence of signals of the same polarity. The signals of opposite polarity from alternate scans are thus also added in phase. Improvement in noise ratio (S/N) obtained is proportional to the square root of twice the number of integration steps. The integration has been performed on a 256 element linear pyroelectric array using 8 and 64 integration steps. The improvement obtained has been experimentally verified in each case.

Paper Details

Date Published: 7 December 1988
PDF: 5 pages
Proc. SPIE 0972, Infrared Technology XIV, (7 December 1988); doi: 10.1117/12.948302
Show Author Affiliations
S. C . Jain, Defence Electronics Applications Laboratory (India)
S. S. Santara, Defence Electronics Applications Laboratory (India)

Published in SPIE Proceedings Vol. 0972:
Infrared Technology XIV
Irving J. Spiro, Editor(s)

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