Minimum Resolvable Contrast Testing of Short-wave IR Camera
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摘要: 评估短波红外相机的综合性能对相机迭代和实际使用效果极为关键,本文提出了一种基于最小可分辨对比度(minimum resolvable contrast,MRC)测试的短波性能评估方法,由积分球辐射多个固定对比度的靶标,并对辐射源强度、目标混叠、观察模式等进行合理控制从而将噪声、目标背景对比度、观察者易变性等影响因子涵盖在评估模型中,综合评估短波相机性能。采用本方法对某型号短波相机进行了MRC测试和外场测试,取得了较为相符的测试结果,其测试不确定度仅为2.11%,可很好地对短波相机进行性能评估和预估。Abstract: Short-wave infrared (SWIR) cameras have several advantages over medium-wave infrared (MWIR) and long-wave infrared (LWIR) cameras. Hence, a method for evaluating their performance is crucial for the application and development of electro-optical systems. We suggest a method that can be used to evaluate the performance of an SWIR camera based on the minimum resolvable vontrast(MRC) test. An integrating sphere and five targets with different contrasts were used. The intensity of the radiation source, aliasing, and observation patterns were controlled to evaluate the SWIR camera performance. We applied this method to test the MRC of the SWIR system. Furthermore, a series of field experiments was conducted, and the results were in agreement with the MRC testing data. The uncertainty of the method reached 2.11%, which supports the conclusion that the MRC method can be applied to evaluate and predict the performance of SWIR cameras.
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Key words:
- short-wave IR /
- minimum resolvable contrast /
- contrast testing /
- targets
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表 1 短波红外相机参数
Table 1. Parameters of the SWIR camera
Wavelength/nm 900-1700 Focal length/mm 136 F/# 4 Detector InGaAs 640×512, 15 μm 表 2 MRC测试结果
Table 2. MRC test data
Contrast Spatial frequency/(cy/mrad) 10% 3.5 30% 4.9896 50% 4.9896 75% 4.9896 90% 4.9896 表 3 测试不确定度
Table 3. Testing uncertainty
Contrast Relative expanded uncertainty 10% 2.11% 30% 1.55% 50% 1.32% 75% 1.47% 90% 1.13% -
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