Field performance evaluation for Heliborne FLIR systems by newly devised conversion methodology

摘要

The conversion methodology for field performance of HFLIR (Heliborne FLIR) systems has been in phenomenon established to get reasonable evaluation for its detection and identification ranges. On the basis of the field performance model with Johnson criterion, the contribution factors affecting on the HFLIR performance are derived as follows: the bar target size, the temperature difference between the black and white in target, the atmospheric transmittance (the visibility, the atmospheric temperature and the humidity), the background temperature, and the instability in the system MRT requirement. Then, by considering those factors, the test and evaluation procedures are set up where the conversion process from the performance measured under real test condition to that at the evaluation criterion is implemented, which is newly devised in this paper. With the help of this methodology, the field performances (the detection and recognition ranges) of HFLIRs on S-LYNX, UH-60 and HH-47 helicopters have been measured and reasonably evaluated to check whether or not their performances meet the requirement of capability (ROC). As for the HFLIR on S-LYNX, the converted detection and recognition ranges are proved to be elongated respectively +10% and -9.2%, compared with the measured ranges. They for the HFLIR on UH-60 turn out to be respectively better +6.2% and +12.4% than the measured ones, and they for HFLIR on HH-47 show performances with conversion rate of +0.4% and +1%. The difference between the converted and the measured ranges, of course, comes from the difference in the real weather conditions at test day and at ROC. This methodology gives so fair and reasonable judgment that it may be very useful for the case that the measured values are comparable to those at ROC within the experimental error