Airborne infrared transmissometer

Abstract

The Airborne Infrared Transmissometer measures the infrared transmission between a test target aircraft and a detection system. A transmitter is attached to an aircraft and emits a calibrated infrared beam. A ground-based, shipborne, or airborne receiver measures the transmitted signals in the exact same path between the target aircraft and the detection system. Data recording equipment can be attached to both the transmitter and receiver to measure the associated outputs.

What is claimed is: 
     
       1. A device for measuring infrared radiation transmission in the changing path between a moving test target aircraft and a ground based, shipborne, or airborne detection station, comprising: means for transmitting a calibrated infrared beam from the test target aircraft; means for measuring infrared radiation from said means for transmitting, said means for measuring infrared radiation located on the ground-based, shipborne, or aircraft detection station.   
     
     
       2. The device of claim 1, wherein said transmitting means comprises an infrared source which produces an infrared radiation beam, a scanning parabolic mirror which scans said infrared radiation beam along the azimuthal direction with a period of 0.7 seconds, and a cylindrical chopper which chops said infrared radiation beam at 100 Hz. 
     
     
       3. The device of claim 1 wherein said means for measuring comprises an infrared radiometer capable of measuring incident radiation amplitude modulated with a frequency of 100± Hz within a certain spectral band. 
     
     
       4. A device for measuring infrared radiation transmission in the moving path between a moving test target aircraft and a ground based, shipborne, or airborne detection station, comprising: a transmitter which produces a calibrated infrared radiation beam which is scanned azimuthally;   means for providing electrical power to said transmitter;   means for receiving and measuring incident radiation from said transmitter located on the ground-based, shipborne, or airborne detection station;   means for aligning said means for receiving and measuring with said transmitter while the path between said transmitter and said means for receiving and measuring is changing;   means for recording signals from said transmitter and said means for receiving and measuring.   
     
     
       5. The device of claim 4 wherein said transmitter is encased in a modified Electromagnetic Support System Navy pod. 
     
     
       6. The device of claim 4 wherein said transmitter power providing means is a ram air turbine generator. 
     
     
       7. The device of claim 4 wherein said receiving aligning means is a pan and tilt tripod which houses said receive. 
     
     
       8. The device of claim 4 wherein said recording means is a magnetic tape recorder.