CN-121977705-A - Infrared detector test evaluation method for cold background point target application

CN121977705ACN 121977705 ACN121977705 ACN 121977705ACN-121977705-A

Abstract

The invention discloses an infrared detector testing and evaluating method for cold background point target application, which is characterized in that a cold background and a cold background overlapping point target are equivalent to be a surface source blackbody temperature for infrared detector testing according to radiation characteristics of an actual background and a target, camera parameters and infrared detector testing system parameters, and infrared detector performance is tested and evaluated in a cold background infrared detector testing cold cabin. The cold cabin is connected with the focal plane refrigerating and temperature measuring and controlling module, the blackbody refrigerating and temperature measuring and controlling module, the acquisition module and the vacuum pump, and can provide high vacuum low background test conditions for extremely low dark current and various photoelectric performances of the high-sensitivity infrared detector. The performance parameters of the infrared detector obtained by the method can provide test data support for actual performance evaluation of the target detection camera of the cold background point.

Inventors

JIN LIBING
TONG WEIMING
CHEN XIN
Zhang Jiushuang
LIAN MINLONG
LI XIN
LI XIAOMAN
MA JING
LI GAOYUE
DONG JIE
DENG XUGUANG

Assignees

北京空间机电研究所

Dates

Publication Date: 20260505
Application Date: 20241209

Claims (10)

1. The infrared detector testing system for the application facing the target of the cold background point is characterized by comprising a cold background infrared detector testing cold cabin, a focal plane refrigerating and temperature measuring and controlling module, a blackbody refrigerating and temperature measuring and controlling module, an acquisition module and a vacuum pump, wherein the cold background infrared detector testing cold cabin is recorded as the cold cabin, and comprises an infrared detector chip to be tested, an optical filter, a cold platform, a cold screen, a platinum resistor, an electric connector, a surface source blackbody and a sliding rail, wherein the cold cabin comprises the following components: The optical filter is packaged in the light incidence direction of the infrared detector chip; the focal plane refrigerating and temperature measuring and controlling module outside the cold cabin is connected with the cold platform and used for regulating and controlling the temperature of the cold platform, the infrared detector, the optical filter and the cold screen in the cold cabin; the surface source black body is arranged on the sliding rail and can move to the front of the cold screen through the sliding rail; The blackbody refrigeration and temperature measurement and control module outside the cold cabin is connected with the surface source blackbody and is used for regulating and controlling the temperature of the surface source blackbody in the cold cabin; Platinum resistors are adhered to the cold screen and the cold platform and used for measuring the temperatures of the cold screen and the cold platform in real time, and an electric signal wire of the platinum resistor is connected with a focal plane refrigerating and temperature measuring and controlling system through an electric connector of a cabin wall of the cold cabin; the infrared detector chip electrical outgoing line is connected with the acquisition module through an electrical connector of the cold cabin wall, and the vacuum pump is connected with the cold cabin to provide a vacuum environment for the cold cabin.
2. An infrared detector test evaluation method for a cold background spot target application using the infrared detector test system of claim 1, comprising: S1, decomposing a maximum allowable dark current value I dark of the infrared detector according to the detection capability of the infrared detector under the application of a cold background point target, and calculating a working temperature value T work of the infrared detector to be detected; S2, calculating the equivalent surface source blackbody temperature T 0 of the background to be detected and the equivalent surface source blackbody temperature T 1 of the target of the superposition point of the background to be detected; S3, packaging the infrared detector chip in a cold background infrared detector test cold cabin; s4, after the vacuum degree of the cold cabin is tested by the cold background infrared detector to be 1 multiplied by 10 -5 Pa, starting a focal plane refrigerating and temperature measuring and controlling module, and performing closed-loop refrigerating and temperature controlling on the infrared detector chip and the cold screen; s5, starting a blackbody refrigeration and temperature measurement and control module, and performing closed-loop refrigeration and temperature control on the surface source blackbody; S6, after the temperature of the infrared detector chip, the cold screen and the surface source blackbody is stabilized at T work , acquiring imaging data of the infrared detector under M grades of integration time, and acquiring N frames each time; S7, fitting and calculating an actually measured dark current value I d ′ ark of the infrared detector according to the M groups of data acquired in the step S6; S8, calculating half-trap integration time t; S9, keeping the temperature of the infrared detector chip and the cold screen at T work , and acquiring N frames of imaging data of the infrared detector in a half-trap integration time T under each temperature state when the temperature of the surface source blackbody is respectively stabilized at T 0 and T 1 ; s10, calculating the performance of the infrared detector according to the two sets of imaging data acquired in the S9, wherein the performance comprises the response voltage average value of the pixels Average response rate of pixels Blind pixel ratio BR, response rate non-uniformity UR, average quantum efficiency QE of pixel.
3. The infrared detector test evaluation method for the cold background point target application of claim 1 is characterized in that S1 decomposes the maximum allowable dark current value I dark of the infrared detector, and the method for calculating the working temperature value T work of the infrared detector to be detected is specifically as follows: s1-a, starting from the overall index of the camera, decomposing the maximum dark current noise voltage V dark of the allowed infrared detector to meet the detection signal-to-noise ratio of the point target; S1-b, calculating a maximum allowable dark current value I dark by using the maximum dark current noise voltage of the infrared detector: wherein, C int is an integrating capacitor, t' is the main integration time of the camera, and e is the charge quantity of one electron; S1-c, calculating the highest working temperature value T work of the infrared detector to be tested according to rule07 rule and the material and the technological level of the infrared detector to be tested.
4. The method for testing and evaluating the infrared detector applied to the cold background spot target according to claim 1, wherein in S2, the equivalent surface source blackbody temperature T 0 of the background to be tested and the equivalent surface source blackbody temperature T 1 of the background superposition spot target to be tested are calculated, specifically: S2-a, calculating total illuminance E b of background radiation reaching an image surface according to a background radiation brightness simulation result L, a camera F number F camera and camera optical system efficiency eta camera in an actual detection scene in a detection spectrum segment lambda 1 ～λ 2 : S2-b, calculating the illuminance E t of the point target radiation reaching the image plane according to the simulation result I of the actual detection point target radiation intensity in the detection spectrum segment lambda 1 ～λ 2 , the camera entrance pupil area phi, the detection distance d, the energy concentration R and the pixel area A d : S2-c, the equivalent surface source blackbody temperature T 0 of the background to be detected meets the following conditions: T 0 is obtained through the back calculation, wherein h is a Planck constant, c is a light speed, k is a Boltzmann constant, lambda is a specific spectrum in a detection spectrum, lambda 1 and lambda 2 are the minimum value and the maximum value of the detection spectrum respectively, F detector is the F number of a cold screen for infrared detector test, eta detctor is the total transmittance of an optical filter, and E l is the simulation result of the arrival of the ray machine heat radiation at the image plane illuminance; S2-d, the equivalent surface source blackbody temperature T 1 of the background superposition point target to be detected meets the following conditions: t 1 is obtained through the inverse calculation of the formula.
5. The infrared detector testing and evaluating method for the cold background point target application of claim 2, wherein the step S3 is to package the infrared detector chip in a cold background infrared detector testing cold cabin, and specifically comprises the following steps: S3-a, opening a cold background infrared detector to test a cold cabin, and mounting an infrared detector chip and a cold screen, which are packaged with an optical filter with a transmission spectrum of lambda 1 ～λ 2 , on a cold platform in the cabin; s3-b, connecting an electrical outgoing line of the infrared detector chip to an electrical connector of the bulkhead and connecting the electrical outgoing line with the acquisition module; S3-c, sticking a temperature-measuring platinum resistor on the cold screen and the cold platform, connecting an electrical signal wire of the platinum resistor to an electrical connector of the bulkhead, and connecting the electrical signal wire with a focal plane refrigerating and temperature measuring module; s3-d, moving the surface source black body to the vicinity of the front of the cold screen through a sliding rail, enabling the surface source black body to cover the whole cold screen opening, and connecting the black body with a black body refrigerating and temperature measuring and controlling module; S3-e, closing the cold background infrared detector to test the cold cabin, and starting a vacuum pump to vacuumize.
6. The method for testing and evaluating the infrared detector applied to the cold background spot target according to claim 1, wherein in step S4, the temperature range which can be realized by the infrared detector chip and the cold screen comprises the working temperature value T work of the infrared detector to be tested; in step S5, the temperature range that can be achieved by the surface source black body includes the working temperature value T work of the infrared detector to be detected.
7. The method for testing and evaluating the infrared detector applied to the cold background point target according to claim 1, wherein in the step S6, when the temperatures of the cold screen and the surface source black body do not exceed the working temperature of the chip, the influence of the radiated photon number on the dark current test of the chip can be ignored, so that the temperatures of the cold screen and the surface source black body are less than or equal to T work , and therefore, the step of collecting imaging data of the infrared detector under the M-stage integration time is as follows: s6-a, gradually increasing the integration time to enable the integration time when the response mean value of the pixel reaches 90% of the full trap to be recorded as t 5 ; S6-b, four integration time values are taken at equal intervals between 0 and t 5 , and the total five-gear integration time is t 1 ,t 2 ,t 3 ,t 4 ,t 5 respectively; s6-c, respectively acquiring imaging data of the infrared detector under the integration time t 1 ,t 2 ,t 3 ,t 4 ,t 5 , and acquiring N frames at each integration time.
8. The method for testing and evaluating the infrared detector for the cold background spot target application according to claim 1, wherein in the step S7, the method for calculating the actually measured dark current value I d ′ ark of the infrared detector is specifically as follows: N-frame voltage average of ith row and jth column pixel (i, j) at integration time t n The method comprises the following steps: Wherein f represents the number of frames; N-frame voltage average value of whole area array The method comprises the following steps: Wherein the pixel scale of the infrared detector is X multiplied by Y; with the t n as the abscissa of the drawing, Taking the ordinate as the linear fitting of the least square method to obtain the slope The measured dark current value I d ′ ark of the infrared detector is Wherein C int is an integrating capacitor.
9. The infrared detector test evaluation method for the cold background spot target application of claim 1, wherein in the step S8, the method for calculating the half-trap integration time T is as follows, according to I d ′ ark obtained in the step S7 and T 0 obtained in the step S2, the half-trap integration time T satisfies the following conditions: T is obtained through the back calculation; Wherein A d is pixel area, Q is predicted quantum efficiency, V sat is saturated voltage, I d ′ ark is actually measured dark current value of an infrared detector, eta detctor is total transmittance of an optical filter, F detector is cold screen F number for infrared detector test, h is Planck constant, C is light speed, k is Boltzmann constant, T 0 is equivalent surface source black body temperature of a background to be detected, C int is integral capacitor, V sat is saturated voltage, e is electric charge quantity of one electron, lambda is specific spectrum in detection spectrum, lambda 1 and lambda 2 are minimum value and maximum value of detection spectrum respectively.
10. The method for testing and evaluating the infrared detector for the cold background spot target application according to claim 1, wherein in step S10, the method for calculating the performance of the infrared detector is specifically as follows: Under the conditions of the equivalent surface source blackbody temperature T 0 of the background to be detected and the equivalent surface source blackbody temperature T 1 of the equivalent surface source blackbody temperature T 0 and the background superposition point target to be detected, the N frame voltages of the pixels (i, j) are respectively averaged as follows: Wherein f represents the number of frames; When the infrared detector outputs in the forward direction, the response voltage V s (i, j) of the pixel (i, j) is: Response voltage average value of all pixels The method comprises the following steps: The dead is dead blind pixel number, namely the pixel number of which the response is lower than 1/2 of the mean value, hot is overheat blind pixel number, namely the pixel number of which the noise is 2 times higher than the mean value, and the pixel scale of the infrared detector is X multiplied by Y; The blind pixel ratio BR is: the response rate R (i, j) of the pixel (i, j) is: Average response rate of all pixels The method comprises the following steps: Wherein, the F detector is the F number of the cold screen for infrared detector test, A d is the pixel area, and sigma is Stet Pan Changshu; The response rate non-uniformity UR is: dead is dead blind pixel number, namely pixel number with response lower than 1/2 of average value, hot is overheat blind pixel number, namely pixel number with noise 2 times higher than average value; the average quantum efficiency QE of all pixels is: Wherein h is Planck constant, C is light speed, k is Boltzmann constant, t is half-trap integration time, C int is integration capacitance, eta detctor is total light filter transmittance, F detector is cold screen F number for infrared detector test, lambda is specific spectrum in detection spectrum, and lambda 1 and lambda 2 are minimum and maximum of detection spectrum respectively.

Description

Infrared detector test evaluation method for cold background point target application Technical Field The invention relates to an infrared detector test evaluation method for cold background point target application, and belongs to the technical field of aerospace remote sensing infrared detectors. Background The infrared detector is a sensor capable of detecting and responding to infrared radiation, and plays a vital role in the aerospace field due to the advantages of high detection sensitivity, strong atmospheric penetrability in the infrared spectrum, good environmental adaptability and the like. The conventional infrared detector test evaluation is based on the national standard GB/T17444-2013 infrared focal plane array parameter test method, the background and target temperature are equivalent to normal temperature 20 ℃ and 35 ℃ surface source blackbody so as to perform response voltage test, and then characteristic parameters such as response rate and the like are calculated according to definition. However, the deep space detection task is aimed at a background and dark spot target with extremely low temperature, so that the photocurrent of the infrared detector is extremely small, the detection spectrum needs to be extended from near infrared to long wave and very long wave infrared, and the normal temperature background and target test method cannot be matched with the actual application scene. In order to ensure the consistency of the testing performance of the infrared detector, firstly, a scene such as target strength, distance, background radiation brightness and the like is clearly detected, then performance indexes such as dark current, quantum efficiency and the like which pay attention to the important points of the infrared detector are obtained by decomposing the task demands of a camera system, and finally, an infrared detector testing method which is matched with the practical application of the camera system is formulated to accurately test and evaluate the key performance of the practical infrared detector. The existing infrared detector test evaluation method is oriented to normal temperature background application and cannot meet the evaluation requirement of deep-space cold background point target application. Disclosure of Invention The invention solves the technical problem of overcoming the defects of the prior art, and provides the infrared detector testing and evaluating method for the cold background point target application, which can meet the evaluating requirement of the deep-space cold background point target application. The technical scheme includes that in the first aspect, an infrared detector testing system for cold background point target application is provided, the infrared detector testing system comprises a cold background infrared detector testing cold cabin, a focal plane refrigerating and temperature measuring and controlling module, a blackbody refrigerating and temperature measuring and controlling module, an acquisition module and a vacuum pump, wherein the cold background infrared detector testing cold cabin is recorded as a cold cabin, and the cold cabin comprises an infrared detector chip to be tested, an optical filter, a cold platform, a cold screen, a platinum resistor, an electric connector, a surface source blackbody and a sliding rail, wherein the cold cabin comprises the following components: The optical filter is packaged in the light incidence direction of the infrared detector chip; the focal plane refrigerating and temperature measuring and controlling module outside the cold cabin is connected with the cold platform and used for regulating and controlling the temperature of the cold platform, the infrared detector, the optical filter and the cold screen in the cold cabin; the surface source black body is arranged on the sliding rail and can move to the front of the cold screen through the sliding rail; The blackbody refrigeration and temperature measurement and control module outside the cold cabin is connected with the surface source blackbody and is used for regulating and controlling the temperature of the surface source blackbody in the cold cabin; Platinum resistors are adhered to the cold screen and the cold platform and used for measuring the temperatures of the cold screen and the cold platform in real time, and an electric signal wire of the platinum resistor is connected with a focal plane refrigerating and temperature measuring and controlling system through an electric connector of a cabin wall of the cold cabin; the infrared detector chip electrical outgoing line is connected with the acquisition module through an electrical connector of the cold cabin wall, and the vacuum pump is connected with the cold cabin to provide a vacuum environment for the cold cabin. In a second aspect, an infrared detector test evaluation method for a target application of a cold background spot is provided, including: S1, decomposing a maximum allo