Abstract
The first video rate imagery from a proof-of-concept 32-channel 22 GHz aperture synthesis imager is reported. This imager has been brought into operation over the first half of year 2011. Receiver noise temperatures have been measured to be ∼453 K, close to original specifications, and the measured radiometric sensitivity agrees with the theoretical predictions for aperture synthesis imagers (2 K for a 40 ms integration time). The short term (few seconds) magnitude stability in the cross-correlations expressed as a fraction was measured to have a mean of 3.45×10-4 with a standard deviation of ∼2.30×10-4, whilst the figure for the phase was found to have a mean of essentially zero with a standard deviation of 0.0181°. The susceptibility of the system to aliasing for point sources in the scene was examined and found to be well understood. The system was calibrated and security-relevant indoor near-field and out-door far-field imagery was created, at frame rates ranging from 1 to 200 frames per second. The results prove that an aperture synthesis imager can generate imagery in the near-field regime, successfully coping with the curved wave-fronts. The original objective of the project, to deliver a Technology Readiness Level (TRL) 4 laboratory demonstrator for aperture synthesis passive millimetre wave (PMMW) imaging, has been achieved. The project was co-funded by the Technology Strategy Board and the Royal Society of the United Kingdom. © 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).
Original language | English |
---|---|
Title of host publication | Proceedings of SPIE - The International Society for Optical Engineering|Proc SPIE Int Soc Opt Eng |
Place of Publication | SPIE 8188 |
Publisher | SPIE |
Volume | 8188 |
ISBN (Print) | 9780819488169 |
DOIs | |
Publication status | Published - 2011 |
Event | Millimetre Wave and Terahertz Sensors and Technology IV - Prague Duration: 1 Jul 2011 → … |
Conference
Conference | Millimetre Wave and Terahertz Sensors and Technology IV |
---|---|
City | Prague |
Period | 1/07/11 → … |
Keywords
- Aperture synthesis
- digital beam-forming
- earth observation
- imaging
- passive
- security screening