| Popis: |
The Plessey Company, in conjunction with the U.K. Ministry of Defence, has developed a range of pyroelectric infrared detectors which in linear and two dimensional array formats may be used at room temperature. Sensor research based upon these devices is carried out at the Royal Signals and Radar Establishment (RSRE) Malvern, and Plessey (Roke Manor). This paper describes sensors employing linear arrays of detectors, and gives examples of imagery that has been obtained. The sensors built to date employ germanium lenses, a chopper to modulate the incoming radiation, and sixty four element linear arrays of detectors. The Plessey system reads the peak value of signal from the detector with the chopper "open" and displays this in the form of a grey-scale picture, whilst the RSRE system takes the difference between the signal with the chopper open and closed and displays this as a grey-scale picture. For the systems discussed, the instantaneous field of view is about 3.5mR and the NETD (Noise Equivalent Temperature Difference) better than 0.2K. The sensors may be used in a panned mode to give large-area surveillance, in a staring mode to provide image information by virtue of the motion of the target or mounted in an aircraft in a linescan mode. Examples of imagery obtained in these modes are presented.© (1986) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only. |
