为了研究噪声对雪崩二极管（APD）探测能力的影响, 采用高光谱图像计算辐射功率的方法, 对APD探测系统的各类噪声的成因及特点进行了分析, 在此基础上归纳了影响系统探测能力的因素, 并对白天状态下背景光功率与信噪比关系、倍增因子与温度关系进行了仿真, 利用高光谱图像的光谱曲线计算背景辐射经大气湍流、大气分子和气溶胶影响后的功率, 进而得到经大气传输后的背景辐射与APD噪声关系。结果表明,偏置电压为340V、背景光由0.07mW增强到0.35mW时, 噪声有效值由108mW增强到150mW, 表明同一偏压下, APD噪声有效值会随着自然背景光功率的增强而增强; 背景光为0.35mW、偏置电压由320V增强到340V时, 噪声有效值由23mW增强到150mW, 表明同一背景光下, 噪声有效值会随偏置电压升高而升高, 且增长速率逐渐加快。此研究表明通过高光谱图像可得到特定区域的背景辐射功率, 并明确了背景辐射对APD噪声特性造成的影响。

In order to study the influence of noise on detection capability of an avalanche photodiode(APD), hyperspectral images were used to calculate radiation power and the causes and characteristics of all kinds of noise in an APD detection system were analyzed. On this basis, the factors affecting the detection capability of the system were summarized. The relationship between signal-to-noise ratio and background light power in daytime and the relationship between multiplier factor and temperature were simulated. The spectral curves of hyperspectral images were used to calculate the power of background after atmospheric turbulence, atmospheric molecules and aerosol, and then the relationship between background radiation and APD noise after atmospheric transmission was obtained. The results show that when the bias voltage is 340V and background light is enhanced from 0.07mW to 0.35mW, the effective value of noise is enhanced from 108mW to 150mW. The effective value of APD noise will be enhanced with the enhancement of the power of natural background light under the same bias voltage. When background light is 0.35mW and bias voltage is enhanced from 320V to 340V, the effective value of noise is enhanced from 23mW to 150mW. Under the same background, the effective value of noise will increase with the increase of the bias voltage, and the growth rate will gradually accelerate. Background power in a specific region can be obtained from hyperspectral images. The influence of background radiation on the APD noise characteristics is also clarified.