利用Σ-Δ型模数转换器解决光辐射定标中弱信号测量的设计难题

Solution to the problem of weak signal measurement in radiometric calibration based on Σ-Δ ADC

随着光学遥感仪器的迅速发展,要求光谱辐射定标技术具有前所未有的高精度和长期测量的稳定性。基于探测器的新一代辐射定标技术可以满足这一需求。多波段绝对辐亮度标准探测器是辐射定标技术中的核心仪器,这种光学遥感仪器在野外、机载和星载高精度辐射定标中具有广阔的应用前景。在多波段绝对辐亮度标准探测器的设计中,需要实现对低电平微弱信号的高精度测量,这种测量通常需要采用可编程增益放大器对信号进行放大,但它不仅会引入测量误差,而且还会增加系统的复杂性。通过采用一种低噪声高精度Δ Σ型模数转换器(ADC),解决了多波段绝对辐亮度标准探测器中弱信号高精度测量的设计难题,为光辐射精确计量领域中经常面临的低电平弱信号的高精度检测提供了一种有效的途径。

With the rapid development of optical remote detectors, the radiometric calibration technology is demanded to reach an entirely new level in the precision and long-term stability. A new advanced high-accuracy radiometric calibration technology based on detector can satisfy the needs. Multi-channel absolute spectral radiance standard detector is a key unit of the new radiometric calibration technology, and has potential applications in radiometric calibration of field, air-borne and space-borne sensors. The high-accuracy measurement of weak signal is a hard technology problem. A solution based on Σ-Δ ADC is given. It is proved that the solution is an effective means to solve the weak signal measurement in the field of optical radiometric high-accuracy measurement.