An overview is presented of ongoing efforts in applied research by the Passive Standoff Detection Team at the U.S. Army Soldier Biological Chemical Command (SBCCOM). Passive infrared sensors such as the TurboFT, the High Sensitivity Field Fourier Transform Infrared Spectrometer (HISPEC), and the Adaptive InfraRed Imaging Spectroradiometer (AIRIS) will be described. The Owl Field Tests were held at the Nevada Test Site for a three-week period from 31 July to 18 August 2000. The AIRIS utilizes a Fabry-Perot tunable filter to spectrally resolve the image, which is captured on a 64x64-element HgCdTe focal-plane-array. The TurboFT uses a spinning crystal design to achieve scan speeds of up to 100 scans/sec with an ultimate goal of 360 scans/sec. The TurboFT utilizes a 16-element (2x8) focal-plane-array. The HISPEC is a single pixel sensor with extremely high sensitivity.