Translator Disclaimer
15 September 1978 Time-Delay-And-Integration Charge Coupled Devices (CCDs) Applied To The Thematic Mapper
Author Affiliations +
Proceedings Volume 0143, Applications of Electronic Imaging Systems; (1978) https://doi.org/10.1117/12.956544
Event: 1978 Technical Symposium East, 1978, Washington, D.C., United States
Abstract
The Thematic Mapper (with its 30 m ground footprint in five-spectral bands from 0.4 μm to 2.0 μm and 120 m GFT in a 10.5 μm to 12.5 μm spectral band) represents the next generation sensor system for application to earth resource survey. The Thematic Mapper (TM) uses a 56 cm x 42 cm oscillating mirror to scan the scene, and is designed to provide accurate radiometric measurements. Currently, in the visible focal plane the discrete detectors must provide 80% quantum efficiency, nominally 100 electrons noise, less than 5% ripple in the spectral response, and 0.5% signal crosstalk to meet system requirements. This focal plane uses complex hybrid assembly techniques to interface silicon photodiodes to JFET preamplifiers. This complexity can be ameliorated by using a new approach in signal pro-cessing which takes advantage of the properties of charge-coupled devices (CCD). A 20-channel time-delay-and-integration (TDI) CCD with nine stages of integration per channel has been built for a TM application. By going to a CCD array which operates in a TDI mode, over 700 individual Op Amps can be replaced with only 48 Op Amps. Smooth spectral response and 70% quantum efficiency have been provided by using doped tin oxide gates over the imaging region. The 20 x 9 TDI device when operated with all 9 integration stages, ,exceeded SNR requirements by a factor of 2. The crosstalk performance is controlled by providing high charge transfer efficiency using a buried channel CCD. The TDI device has demonstrated charge integration for both forward and reverse scans of the oscillating mirror, and a form of exposure control is provided by integrating over 3, 6, or all 9 stages in either direction of scan.
© (1978) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Leslie L. Thompson and David H. McCann "Time-Delay-And-Integration Charge Coupled Devices (CCDs) Applied To The Thematic Mapper", Proc. SPIE 0143, Applications of Electronic Imaging Systems, (15 September 1978); https://doi.org/10.1117/12.956544
PROCEEDINGS
8 PAGES


SHARE
Advertisement
Advertisement
RELATED CONTENT

New CCD imagers for adaptive optics wavefront sensors
Proceedings of SPIE (August 03 2014)
Design of image sensors for hyperspectral applications
Proceedings of SPIE (September 22 2009)
Detectors for biotechnology
Proceedings of SPIE (June 18 2003)
Performance based CID imaging: past, present, and future
Proceedings of SPIE (August 26 2008)
Subelectron read noise at MHz pixel rates
Proceedings of SPIE (May 14 2001)

Back to Top