Measurement of Mid-Wave Infrared Hyperspectral Imaging Characteristics of Ground Targets
The Hyper-Cam medium-wave hyperspectral imager designed by Telops was used to measure the infrared hyperspectral imaging of a tank model on the cement floor in the 3～5 μm band.Atmospheric correction is performed on a pixel-by-pixel basis of the experimental data.Finally,according to the corrected experimental data,the effects of instrument,random,and atmospheric correction transmission errors on the test uncertainty were analyzed.The luminance distribution of the tank model on different spectral bands and the spectral distribution characteristics of different parts of the model were also analyzed.The results show that the relative uncertainty of the wavenumber in the band of 2 000～3 000 cm 1 has been stable w ithin 10％,but in the band greater than 3 000 cm-1,the error rises rapidly.The error is mainly because the medium-wave radiation of the normal temperature object is low,and the target radiation in this band is close to the atmospheric radiation of the distance,and the noise caused by the increase of the noise caused by the decrease of the test signal-to-noise ratio is reduced.The average relative uncertainty of the tank model's spectral radiation brightness test data is within 17％,and the overall error is low,which has reached the advanced level in China.In terms of spectral distribution,the difference in the spectral radiation brightness of the characteristic points of each part of the tank and the cement surface in the wavelength of 4.2～5 μm is greater than that in the wavelength of 3.0～4.2 μm,and the spectral radiation brightness in the 4.2～5 μm band emitted by the detector is greater than the spectral radiation brightness of 3.0～4.2 μm in the shorter band.Since the 4.3 μm band is in the atmospheric absorption band,the average transmittance calculated by Modtran is almost 0,so a true measurement of the spectral radiation brightness on the target cannot be obtained.Regarding spatial distribution,the radiation brightness of the model is mainly concentrated on the side coating,and the radiation brightness at the muzzle and track is small.The radiant brightness distribution of typical target parts is significantly different from that of the surrounding cement surface.Among them,4.4～4.8μm occupies a high radiation brightness ratio,and this band's imaging effect is the best.The proportion of radiation brightness occupied by 3.2～3.8 μm is low,and the imaging effect in this band is poor.In the 4.2～4.4 μm band under the atmospheric absorption zone,because the atmospheric transmittance is almost 0,the accurate spatial radiation brightness distribution cannot be obtained.The results show that the extended medium-wave hyperspectral imager has the characteristics of accurate target discrimination,small error and"image spectrum integration"in the study of the medium-wave infrared hyperspectral imaging characteristics of ground targets,and the test data can be applied to the infrared hyperspectral stealth design of the target.
NETL
NSTL
万方数据
