A semiactive method of Fourier-transform infrared (FTIR) remote sensing has been developed and field tested. The method replaces the sender telescope of an active technique with an extended, heated broadband source. The output of the extended source (a commercial griddle) is not collimated and thus facilitates alignment by having the detector optics simply point at the griddle. The present source fills the detector’s field of view at 100 m and maintains a temperature ~80 K warmer than ambient. In field tests with live CO releases, the method was ~30 times less sensitive than active methods, but ~30 times more sensitive than passive methods, with far greater sensitivity in the midwave infrared.
© 2004 Optical Society of America
(070.0070) Fourier optics and signal processing : Fourier optics and signal processing
(120.0120) Instrumentation, measurement, and metrology : Instrumentation, measurement, and metrology
(280.0280) Remote sensing and sensors : Remote sensing and sensors
(300.0300) Spectroscopy : Spectroscopy
Timothy J. Johnson, Bruce A. Roberts, and James F. Kelly, "Semiactive Infrared Remote Sensing: A Practical Prototype and Field Comparison," Appl. Opt. 43, 638-650 (2004)