High-dynamic-range infrared radiometer based on chaos detection method

A High-dynamic-range infrared (IR) radiometer is essential for calibrating a wide-temperature-range IR radiation source. However, a low-temperature radiation source has very weak IR radiation which is easily submerged in noise. In this paper, a chaos detection method based on Diffing-Holmes oscillator (DHO) was adopted to enhance the ability of the IR radiometer for measuring weak IR radiation. The power measurement range of the radiometer was 2.9 × 10⁻⁹–5.9 × 10⁻² W. The minimum SNR that was detected by the radiometer was as low as –22.46 dB. The noise during the measurement including the mismatch noise, the stray noise, and the detector noise were analyzed. The radiometer is calibrated by measuring a radiation source with adjustable temperature and aperture. The results show that the responsivity of the radiometer is 8.61257 × 10⁴ V/W. The combined standard uncertainty of the radiometer is less than 1.66%. The IR radiometer introduced in this paper is capable of calibrating the IR radiation source of ultralow temperature, and has been applied in the ground test of a space-borne IR detection system.