Infrared camera has more and more application in military, judicature, rescue, industry, hospital and science. Nowadays the NETD (Noise Equivalent Temperature Difference) of high-sensitivity cooled infrared camera is less than 10 mK. If we test the NETD from the analog video output port of infrared camera using 8-bit and 10-bit ADC frame grabber, the NETD accuracy is 7.81 mK and 2.76 mK which correspond to relative error 78.7% and 27.6% for a 10 mK NETD infrared camera. Such kind of accuracy is obviously not proper for the performance evaluation of high-sensitivity infrared camera with NETD less than 10 mK. The NETD test accuracy can be improved by increasing the effective bit number of the ADC of frame grabber. The quantization error of ADC of frame grabber has become the main factor which contributes most to the NETD error of the high-sensitivity infrared camera. It is difficult to evaluate the electrooptical performance of the high-sensitivity infrared camera through its analog video.Although the NETD test accuracy can be improved by reducing the linear temperature range or increasing the effective bits of the ADC of frame grabber under analog video interface test condition, it is difficult to meet the test needs. But under the 14 bits digital video interface test condition and 1 K linear range, the NETD test accuracy of 0.24 mK can be achieved. The NETD accuracy can be also improved by reducing the linear temperature range. The NETD test accuracy can be 0.488 mK through 14-bit digital video under 2 K linear temperature range and its relative error equals 4.9% for a 10 mK NETD high-sensitivity infrared camera which meets the requirement. The test result through the digital video port of an infrared camera shows that the test result through digital video port matches with its nominal value. This necessitates the need of digital video interface of high-sensitivity infrared camera in NETD test in order to evaluate its performance accuracy.

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The Micro-Opto-Electro-Mechanical Systems (MOEMS) accelerometer is a new type of accelerometer that combines the merits of optical measurement and Micro-Electro-Mechanical Systems (MEMS) to enable high precision, small volume, and anti-electromagnetism disturbance measurement of acceleration, which makes it a promising candidate for inertial navigation and seismic monitoring. This paper proposes a modified micro-grating-based accelerometer and introduces a new design method to characterize the grating interferometer. A MEMS sensor chip with high sensitivity was designed and fabricated, and the processing circuit was modified. The micro-grating interference measurement system was modeled, and the response sensitivity was analyzed. The accelerometer was then built and benchmarked with a commercial seismometer in detail. Compared to the previous prototype in the experiment, the results indicate that the noise floor has an ultra-low self-noise of 15 ng/Hz1/2.