CN113945279B - Test method for solar diffuse reflection calibration aperture factor of space optical remote sensing instrument - Google Patents
Test method for solar diffuse reflection calibration aperture factor of space optical remote sensing instrument Download PDFInfo
- Publication number
- CN113945279B CN113945279B CN202111071492.XA CN202111071492A CN113945279B CN 113945279 B CN113945279 B CN 113945279B CN 202111071492 A CN202111071492 A CN 202111071492A CN 113945279 B CN113945279 B CN 113945279B
- Authority
- CN
- China
- Prior art keywords
- diffuse reflection
- aperture
- reflection plate
- remote sensing
- sensing instrument
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000003287 optical effect Effects 0.000 title claims abstract description 16
- 238000010998 test method Methods 0.000 title description 5
- 238000000034 method Methods 0.000 claims abstract description 25
- 238000001228 spectrum Methods 0.000 claims abstract description 16
- 230000003595 spectral effect Effects 0.000 claims abstract description 11
- 238000012360 testing method Methods 0.000 claims abstract description 8
- 238000005259 measurement Methods 0.000 claims abstract description 7
- 239000000463 material Substances 0.000 claims abstract description 4
- 230000005855 radiation Effects 0.000 claims description 6
- 238000012546 transfer Methods 0.000 claims description 4
- 238000005286 illumination Methods 0.000 claims description 3
- 238000005316 response function Methods 0.000 claims description 3
- 238000011545 laboratory measurement Methods 0.000 claims description 2
- 238000000691 measurement method Methods 0.000 abstract description 2
- 238000000411 transmission spectrum Methods 0.000 description 5
- 238000013461 design Methods 0.000 description 1
- 239000003550 marker Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000004088 simulation Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
- G01J1/00—Photometry, e.g. photographic exposure meter
- G01J1/56—Photometry, e.g. photographic exposure meter using radiation pressure or radiometer effect
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Spectrometry And Color Measurement (AREA)
- Photometry And Measurement Of Optical Pulse Characteristics (AREA)
Abstract
The invention discloses a testing method of solar diffuse reflection scaling aperture factors of a space optical remote sensing instrument, which comprises the following steps: (1) Placing a full-aperture diffuse reflection plate which is in the same batch, material and process as the diffuse reflection plate in the on-board calibration cabin and is parallel to the diffuse reflection plate; (2) a collimated light source illuminating a full aperture diffuse reflecting plate; (3) The remote sensing instrument and the spectrum radiometer synchronously observe the full aperture diffuse reflection plate; (4) a local aperture diffuse reflection plate illuminated by a collimated light source; (5) The remote sensing instrument and the spectrum radiometer synchronously observe the local aperture diffuse reflection plate; (6) calculating a weighted average spectral radiance; (7) calculating a system level measurement of the aperture factor. The method and the process are simple and easy to implement, and have good universality; the full aperture and local aperture diffuse reflection plate comparison measurement method based on the system-level complete link is adopted, and the diffuse reflection plate is synchronously monitored.
Description
Technical Field
The invention belongs to the technical field of optical remote sensing instrument radiometric calibration, and particularly relates to a method for testing solar diffuse reflection calibration aperture factors of a space optical remote sensing instrument.
Background
At present, the international mainstream typical space optical remote sensing instrument basically adopts an on-orbit absolute radiation calibration technical scheme of a solar+ diffuse reflection plate or a solar+ attenuation screen+ diffuse reflection plate, and uniform and highly stable solar radiation is introduced to serve as a standard source for on-orbit radiation calibration of a reflection band. Ideally, a full aperture, full optical path, full field of view solar diffuse reflector calibration scheme is preferred. In the design stage of the space optical remote sensing instrument, the size of the diffuse reflection plate can not realize the full aperture under the constraint of factors such as volume, weight, optical mechanical structure layout and the like, and a solar diffuse reflection calibration scheme with local aperture is usually adopted.
One parameter that is very important for a local aperture scheme is the aperture factor. The method for obtaining the aperture factor mainly comprises a partial aperture and full aperture diaphragm geometric dimension measurement method, an optical software system simulation method and the like, and the aperture factors given by the methods are basically ideal values. For a remote sensing instrument with a complex system structure, the value can be very different from the real aperture factor of the system, and the accuracy of solar diffuse reflection calibration is seriously affected.
Therefore, a system-level test method for calibrating the aperture factor by solar diffuse reflection of the space optical remote sensing instrument needs to be researched, and the measurement accuracy of the aperture factor is improved.
Disclosure of Invention
The invention aims to solve the technical problems that the prior method can only give the theoretical value of the aperture factor and cannot realize the system-level high-precision measurement of the aperture factor, and severely restricts the solar diffuse reflection calibration precision of a remote sensing instrument. The invention provides a system-level high-precision test method for solar diffuse reflection calibration aperture factors of a space optical remote sensing instrument.
In order to solve the problems, the method for testing the solar diffuse reflection calibration aperture factor of the space optical remote sensing instrument comprises the following specific steps:
(1) Placing a diffuse reflection plate with the same batch, same material, same process and parallel full aperture size as the diffuse reflection plate in the on-board calibration cabin at the forefront end of a ground observation light path of the remote sensing instrument;
(2) Adopting a high-stability and high-repeatability collimation light source to simulate the divergence angle of the sun and the full aperture diffuse reflection plate in the intensity illumination step (1);
(3) Observing and collecting the response signal of the illuminated full-aperture diffuse reflection plate in the step (2) by a remote sensing instrument, and marking the response signal as DN full The method comprises the steps of carrying out a first treatment on the surface of the Synchronously adopting a high-precision standard transfer spectrum radiometer to measure the spectrum radiance of the diffuse reflection plate in the same observation direction as that of a remote sensing instrument, and recording as
(4) Adjusting the position of a remote sensing instrument to enable the collimation light sources in the same state in the step (2) to illuminate the local aperture diffuse reflection plate in the on-satellite calibration cabin in the same incidence direction;
(5) Observing and collecting diffuse reflection plate response signals in the illuminated on-board calibration cabin in the step (4) by a remote sensing instrument, and marking the signals as DN par The method comprises the steps of carrying out a first treatment on the surface of the Synchronously adopting a high-precision standard transfer spectrum radiometer to measure the spectrum radiance of the diffuse reflection plate in the same observation direction as that of a remote sensing instrument, and recording as
(6) Calculating a weighted average spectral radiance over a bandAnd->
(7) According to a radiation calibration equation L=f (DN) of a ground observation light path of a remote sensing instrument before emission, calculating an on-board solar diffuse reflection calibration aperture factor by combining the response signals measured in the steps and the weighted average spectrum radianceWhere L is the radiance received by the instrument, DN is the response signal of the instrument, and f is a functional expression of the scaling equation.
Preferably, the weighted average spectral radiance in the band of step (6)Wherein lambda is wavelength lambda 1 、λ 2 The lower and upper wavelength limits, respectively; r (λ) is the instrument spectral response function of the pre-emission laboratory measurement.
Compared with the prior art, the method has the following advantages:
the testing method and the testing flow are simple and easy to implement, and have good universality.
The invention adopts the method for comparing and measuring the full aperture diffuse reflection plate of the earth observation light path and the local aperture diffuse reflection plate in the on-board calibration cabin, the method is based on the system-level real full link test process of the remote sensing instrument, and adopts the high-precision standard transmission spectrum radiometer to synchronously monitor the spectrum radiance of the diffuse reflection plate in the test process, and the measurement result of the method is closer to the system true value than the prior method, and has higher measurement precision no matter the relative distribution or absolute value of aperture factors between wave bands or fields.
Drawings
FIG. 1 is a schematic flow chart of an implementation of an embodiment of the present invention.
Detailed Description
The following describes the embodiments of the present invention in further detail with reference to the drawings.
The specific implementation of the test method of the solar diffuse reflection scaling aperture factor of the space optical remote sensing instrument disclosed by the invention requires 7 steps as shown in figure 1.
(1) And placing the full-aperture size diffuse reflection plate.
And placing a diffuse reflection plate with the same batch, same material and same process as the diffuse reflection plate in the on-board calibration cabin at the forefront end of the earth observation light path of the remote sensing instrument.
And adjusting the full-aperture diffuse reflection plate to be parallel to the local aperture diffuse reflection plate in the on-board calibration cabin by using auxiliary adjusting tools such as a theodolite, a two-dimensional turntable and a marker mirror and the like of the full-aperture diffuse reflection plate.
(2) The collimation light source illuminates the full aperture diffuse reflecting plate.
The full aperture diffuse reflection plate in the step (1) is illuminated by adopting a high-stability and high-repeatability collimation light source (similar to a solar simulator) to simulate the divergence angle and the intensity of the sun.
The beam width of the collimated light source is required to completely cover the full aperture diffuse reflector surface.
(3) The remote sensing instrument and the standard transmission spectrum radiometer synchronously observe the full aperture diffuse reflection plate.
After the collimation light source in the step (2) is in a stable state, the remote sensing instrument observes and acquires the response signal DN of the illuminated full-aperture diffuse reflection plate full 。
The spectrum radiance of the diffuse reflection plate is measured synchronously or quasi-synchronously by adopting a high-precision standard transmission spectrum radiometer to keep the same observation direction as a remote sensing instrument
(4) The collimation light source illuminates the partial aperture diffuse reflecting plate.
And (3) adjusting the position of the remote sensing instrument to enable the collimation light sources in the same state in the step (2) to illuminate the local aperture diffuse reflection plate in the on-satellite calibration cabin in the same incidence direction. Here, "the same state" mainly means that parameters such as stability, divergence angle, intensity and the like of the collimated light source are consistent with those in the step (2); the same incidence direction means that the included angle between the illumination direction of the collimation light source and the normal direction of the diffuse reflection plate is consistent with that in the step (2).
Also, the beam width of the collimated light source is required to completely cover the surface of the local aperture diffuse reflecting plate in the on-board calibration chamber.
(5) The remote sensing instrument and the standard transmission spectrum radiometer synchronously observe the local aperture diffuse reflection plate.
After the collimation light source in the step (4) is in a stable state, the remote sensing instrument observes and acquires a diffuse reflection plate response signal DN in the illuminated on-board calibration cabin par 。
Using high precision for synchronisation or quasisynchronisationThe standard transmission spectrum radiometer keeps the same observation direction as the remote sensing instrument to measure the spectrum radiance of the diffuse reflection plate
(6) Calculating a weighted average spectral radiance over a bandAnd->
Calculating the weighted average spectral radiance in the wave band when observing the full aperture diffuse reflection plate according to the spectral response function R (lambda) of the instrument measured by the laboratory before emissionAnd weighted average spectral radiance when observing a local aperture diffuse reflection plate +.>Wherein lambda is wavelength lambda 1 、λ 2 The lower and upper wavelength limits, respectively.
(7) A system level measurement of the aperture factor is calculated.
According to a radiation calibration equation L=f (DN) of a ground observation light path of a remote sensing instrument before emission, calculating an on-board solar diffuse reflection calibration aperture factor by combining the response signals measured in the steps and the weighted average spectrum radianceWhere L is the radiance received by the instrument, DN is the response signal of the instrument, and f is a functional expression of the scaling equation.
The above description is only an example of the invention and is not intended to limit the embodiments, nor is it intended to be exhaustive of all embodiments. Any modifications, equivalent substitutions or obvious changes or variations from these will occur to those skilled in the art, which are within the spirit and principles of the present invention, are intended to be included within the scope of the present invention.
Claims (2)
1. The method for testing the solar diffuse reflection calibration aperture factor of the space optical remote sensing instrument is characterized by comprising the following steps of:
(1) Placing a diffuse reflection plate with the same batch, same material, same process and parallel full aperture size as the diffuse reflection plate in the on-board calibration cabin at the forefront end of a ground observation light path of the remote sensing instrument;
(2) Adopting a high-stability and high-repeatability collimation light source to simulate the divergence angle of the sun and the full aperture diffuse reflection plate in the intensity illumination step (1);
(3) Observing and collecting the response signal of the illuminated full-aperture diffuse reflection plate in the step (2) by a remote sensing instrument, and marking the response signal as DN full The method comprises the steps of carrying out a first treatment on the surface of the Synchronously adopting a high-precision standard transfer spectrum radiometer to measure the spectrum radiance of the diffuse reflection plate in the same observation direction as that of a remote sensing instrument, and recording asLambda is the wavelength;
(4) Adjusting the position of a remote sensing instrument to enable the collimation light sources in the same state in the step (2) to illuminate the local aperture diffuse reflection plate in the on-satellite calibration cabin in the same incidence direction;
(5) Observing and collecting diffuse reflection plate response signals in the illuminated on-board calibration cabin in the step (4) by a remote sensing instrument, and marking the signals as DN par The method comprises the steps of carrying out a first treatment on the surface of the Synchronously adopting a high-precision standard transfer spectrum radiometer to measure the spectrum radiance of the diffuse reflection plate in the same observation direction as that of a remote sensing instrument, and recording asLambda is the wavelength;
(6) Calculating the weighted average spectral radiance in the band of two measurementsAnd->
(7) According to a radiation calibration equation L=f (DN) of a ground observation light path of a remote sensing instrument before emission, calculating an on-board solar diffuse reflection calibration aperture factor by combining the response signals measured in the steps and the weighted average spectrum radianceWhere L is the radiance received by the instrument, DN is the response signal of the instrument, and f is a functional expression of the scaling equation.
2. The method for measuring solar diffuse reflection scaling aperture factor of spatial optical remote sensing instrument as defined in claim 1, wherein step (6) is characterized by weighted average spectral radiance in said bandWherein lambda is wavelength lambda 1 、λ 2 The lower and upper wavelength limits, respectively; r (λ) is the instrument spectral response function of the pre-emission laboratory measurement.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111071492.XA CN113945279B (en) | 2021-09-14 | 2021-09-14 | Test method for solar diffuse reflection calibration aperture factor of space optical remote sensing instrument |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111071492.XA CN113945279B (en) | 2021-09-14 | 2021-09-14 | Test method for solar diffuse reflection calibration aperture factor of space optical remote sensing instrument |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN113945279A CN113945279A (en) | 2022-01-18 |
| CN113945279B true CN113945279B (en) | 2023-09-12 |
Family
ID=79328181
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111071492.XA Active CN113945279B (en) | 2021-09-14 | 2021-09-14 | Test method for solar diffuse reflection calibration aperture factor of space optical remote sensing instrument |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113945279B (en) |
Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3084253A (en) * | 1960-09-06 | 1963-04-02 | Barnes Eng Co | Continuously self-calibrating differential detection system |
| US3775620A (en) * | 1972-08-24 | 1973-11-27 | Mc Donnell Douglas Corp | Radiation source simulation means |
| SU1433192A1 (en) * | 1987-01-20 | 1990-12-30 | Всесоюзный Онкологический Научный Центр Академии Медицинских Наук Ссср | Method of colorimetric detection of tumorous tissue |
| US6556264B1 (en) * | 1997-04-25 | 2003-04-29 | Semiconductor Energy Laboratory Co., Ltd. | Method of manufacturing an active matrix-type liquid crystal device using a semiconductor thin film having an organic resin interlayer insulating film |
| US6573856B1 (en) * | 2002-01-03 | 2003-06-03 | Lockheed Martin Corporation | Method of synthesizing topographic data |
| US7166825B1 (en) * | 2005-05-17 | 2007-01-23 | Itt Manufacturing Enterprises, Inc. | Solar calibration device and method |
| CN105157827A (en) * | 2015-04-23 | 2015-12-16 | 中国科学院长春光学精密机械与物理研究所 | Integrating sphere transmission radiometer for ontrack spectrum radiation absolute calibration for remote sensor |
| CN105352609A (en) * | 2015-11-13 | 2016-02-24 | 北京空间飞行器总体设计部 | Optical remote-sensing satellite absolute radiation scaling method based on spatial Lambert globe |
| CN106643796A (en) * | 2016-12-02 | 2017-05-10 | 北京空间机电研究所 | Radiometric calibration method based on on-orbit benchmark satellite |
| JP2018036056A (en) * | 2016-08-29 | 2018-03-08 | 日置電機株式会社 | Light power meter |
| CN108981916A (en) * | 2018-08-01 | 2018-12-11 | 合肥中科九衡科技有限公司 | A kind of collecting method based on multichannel filter radiometer |
| CN109374547A (en) * | 2018-11-14 | 2019-02-22 | 中国科学院合肥物质科学研究院 | A kind of calibration optical system based on geostationary orbit difference absorption spectrum instrument |
| EP3536224A1 (en) * | 2018-03-07 | 2019-09-11 | Koninklijke Philips N.V. | System for measuring skin pores |
| CN112461512A (en) * | 2020-11-11 | 2021-03-09 | 北京空间机电研究所 | On-satellite radiometric calibration method and device for large-caliber space optical remote sensor |
| CN113029336A (en) * | 2021-03-10 | 2021-06-25 | 东华理工大学 | Space remote sensing instrument on-satellite radiometric calibration device and calibration method |
| CN114216559A (en) * | 2021-12-16 | 2022-03-22 | 中国科学院合肥物质科学研究院 | Partial aperture factor measuring method and device of on-satellite calibration mechanism |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7145125B2 (en) * | 2003-06-23 | 2006-12-05 | Advanced Optical Technologies, Llc | Integrating chamber cone light using LED sources |
| US7688438B2 (en) * | 2005-12-20 | 2010-03-30 | Raytheon Company | Scanning solar diffuser relative reflectance monitor |
| JP5371813B2 (en) * | 2010-01-28 | 2013-12-18 | 株式会社ジャパンディスプレイ | Driving method of image display device and driving method of image display device assembly |
-
2021
- 2021-09-14 CN CN202111071492.XA patent/CN113945279B/en active Active
Patent Citations (16)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3084253A (en) * | 1960-09-06 | 1963-04-02 | Barnes Eng Co | Continuously self-calibrating differential detection system |
| US3775620A (en) * | 1972-08-24 | 1973-11-27 | Mc Donnell Douglas Corp | Radiation source simulation means |
| SU1433192A1 (en) * | 1987-01-20 | 1990-12-30 | Всесоюзный Онкологический Научный Центр Академии Медицинских Наук Ссср | Method of colorimetric detection of tumorous tissue |
| US6556264B1 (en) * | 1997-04-25 | 2003-04-29 | Semiconductor Energy Laboratory Co., Ltd. | Method of manufacturing an active matrix-type liquid crystal device using a semiconductor thin film having an organic resin interlayer insulating film |
| US6573856B1 (en) * | 2002-01-03 | 2003-06-03 | Lockheed Martin Corporation | Method of synthesizing topographic data |
| US7166825B1 (en) * | 2005-05-17 | 2007-01-23 | Itt Manufacturing Enterprises, Inc. | Solar calibration device and method |
| CN105157827A (en) * | 2015-04-23 | 2015-12-16 | 中国科学院长春光学精密机械与物理研究所 | Integrating sphere transmission radiometer for ontrack spectrum radiation absolute calibration for remote sensor |
| CN105352609A (en) * | 2015-11-13 | 2016-02-24 | 北京空间飞行器总体设计部 | Optical remote-sensing satellite absolute radiation scaling method based on spatial Lambert globe |
| JP2018036056A (en) * | 2016-08-29 | 2018-03-08 | 日置電機株式会社 | Light power meter |
| CN106643796A (en) * | 2016-12-02 | 2017-05-10 | 北京空间机电研究所 | Radiometric calibration method based on on-orbit benchmark satellite |
| EP3536224A1 (en) * | 2018-03-07 | 2019-09-11 | Koninklijke Philips N.V. | System for measuring skin pores |
| CN108981916A (en) * | 2018-08-01 | 2018-12-11 | 合肥中科九衡科技有限公司 | A kind of collecting method based on multichannel filter radiometer |
| CN109374547A (en) * | 2018-11-14 | 2019-02-22 | 中国科学院合肥物质科学研究院 | A kind of calibration optical system based on geostationary orbit difference absorption spectrum instrument |
| CN112461512A (en) * | 2020-11-11 | 2021-03-09 | 北京空间机电研究所 | On-satellite radiometric calibration method and device for large-caliber space optical remote sensor |
| CN113029336A (en) * | 2021-03-10 | 2021-06-25 | 东华理工大学 | Space remote sensing instrument on-satellite radiometric calibration device and calibration method |
| CN114216559A (en) * | 2021-12-16 | 2022-03-22 | 中国科学院合肥物质科学研究院 | Partial aperture factor measuring method and device of on-satellite calibration mechanism |
Non-Patent Citations (1)
| Title |
|---|
| 李秀举 等.扫描经热辐射校正对FY-4A星AGRI定标精度的提升研究.《红外与毫米波学报》.2022,第41卷(第3期),608-617. * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN113945279A (en) | 2022-01-18 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN102486404A (en) | Ultraviolet low-light stellar magnitude simulation and stellar magnitude calibration system | |
| RU2705767C1 (en) | Device and method of measuring spectral sensitivity of a large diameter radiometer | |
| CN111174911B (en) | Method for calibrating absolute radiation of any ground object of space optical camera | |
| CN108180999A (en) | Infrared detector absolute response degree robot scaling equipment and method based on laser scanning | |
| CN109297685A (en) | A kind of spectral transmittance test device and method for heavy caliber parallel light tube | |
| CN110231090A (en) | A kind of test method of thermal infrared spectrum instrument internal stray radiation | |
| CN114216559B (en) | Partial aperture factor measuring method and device for on-board calibration mechanism | |
| CN201983798U (en) | Ultraviolet dim light magnitude simulation and calibration system | |
| CN113945279B (en) | Test method for solar diffuse reflection calibration aperture factor of space optical remote sensing instrument | |
| CN113091892A (en) | On-orbit satellite absolute radiometric calibration method and system for satellite remote sensor | |
| CN116358696B (en) | Micro-light source radiation calibration transfer adjustment system and method adopting laser level meter | |
| Ohno | Realization of NIST 1995 luminous flux scale using the integrating sphere method | |
| Ohno | New method for realizing a luminous flux scale using an integrating sphere with an external source | |
| CN105509895A (en) | Radiation calibration method of spectral temperature measurer with telescopic optical system | |
| CN109655158B (en) | Hyperspectral remote sensor on-orbit spectrum calibration method based on atmospheric profile and LED | |
| CN113945278B (en) | Method for calibrating radiation of reflection band on-orbit full dynamic range of space optical remote sensing instrument | |
| Peltoniemi et al. | Bidirectional reflectance spectrometry of gravel at the Sjökulla test field | |
| Ohno | Improved photometric standards and calibration procedures at NIST | |
| CN111721503B (en) | Vacuum ultraviolet band spectrum calibration device and method for satellite-borne hyperspectral remote sensing camera | |
| CN111323121A (en) | Ultraviolet spectrum remote sensing instrument wide-range linearity testing device and method | |
| Samedov et al. | Filter-radiometer-based realization of candela and establishment of photometric scale at UME | |
| CN105738298B (en) | A kind of aqueous solution turbidimetry method and device based on chromaticity coordinates value | |
| Cao et al. | Research and development of a luminance responsivity standard system at the Vietnam Metrology Institute | |
| CN115639124B (en) | Device and method for realizing soot concentration measurement and in-situ calibration by single-wavelength laser | |
| CN107655931A (en) | A kind of high-precision cylinder linear expansion coefficient measurement apparatus and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |