收稿：2018-07-02，
纸质出版：2020-03-07
移动端阅览
风云三号D星（FY-3D）微波成像仪采用10.65 GHz、18.7 GHz、23.8 GHz、36.5 GHz和89.0 GHz双极化通道对地表辐射信息进行测量，定标精度会直接影响遥感数据的准确性。影响定标精度的主要因素之一是成像仪系统的非线性特征，用物理参数—非线性系数表示。所以准确计算非线性系数是地面热真空定标试验的主要目的之一，在95—298 K范围内设置不同变温源温度点，每一个温度点对应一个非线性系数，这些非线性系数的平均值即是系统最终的非线性系数值。受系统原理和试验条件的限制，计算平均值时需要确定变温源温度的有效范围，目前使用的范围确定方法是设计师首先依据经验提出几组可能的温度范围，然后对比每个范围的定标结果，选出最优的温度范围。显然，这种方法很容易受到人为因素的影响，而且由于不具备遍历所有温度范围的试验条件，无法确定每个变温源温度点的有效性。为了准确获得非线性系数值，首先通过分析热真空定标试验数据证明非线性系数与场景亮温无关，然后提出了一种优化计算方法，采用t准则确定有效范围得到非线性系数值。对比优化前后两种方法的结果表明，新方法的非线性亮温拟合残差的平均值和标准差值以及非线性亮温的最大拟合值都减小了。由此可见，新方法在计算非线性系数时可以获得更准确的变温源温度范围，可以优化非线性亮温的拟合效果，并且将定标精度提高0.04 K，优化效果在10 GHz接收机以及环境温度较高时尤为明显。
The Earth’s radiation was observed by a microwave radiation imager (MWRI) on board FengYun-3D (FY-3D) satellite at 10.65 GHz
18.7 GHz
23.8 GHz
36.5 GHz
and 89.0 GHz with dual polarization. The nonlinearity of this payload
as an important parameter in calibration algorithms
is represented by the nonlinear parameter
<math id="M1"><mi>u</mi></math>
http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=21167728&type=
http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=21167726&type=
1.52399993
2.11666679
from vacuum calibration ground tests. Therefore
an accurate knowledge on the nonlinear characteristics of MWRI is required to achieve precise remote sensing.
The nonlinear parameter applied in the calibration algorithm is usually averaged over a set of
<math id="M2"><mi>u</mi></math>
http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=21167732&type=
http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=21167730&type=
1.52399993
2.11666679
which is calculated at corresponding observed brightness temperatures in the range between 95 K and 298 K. A t-distribution test method is proposed to screen
<math id="M3"><mi>u</mi></math>
http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=21167735&type=
http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=21167734&type=
1.52399993
2.11666679
and further optimize the nonlinearity calculations in this study instead of conventional empirically filtering of
<math id="M4"><mi>u</mi></math>
http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=21167739&type=
http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=21167737&type=
1.52399993
2.11666679
before averaging. The t-method examines the validity of
<math id="M5"><mi>u</mi></math>
http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=21167742&type=
http://html.publish.founderss.cn/rc-pub/api/common/picture?pictureId=21167741&type=
1.52399993
2.11666679
values at each observed brightness temperatures
and its effectivity is proven in this study.
Nonlinear fitting brightness temperatures
as well as means and standard deviation of residual error
were calculated using empirically filtering method and the t-method to demonstrate the results in the nonlinearity calculation. The nonlinear parameter of MWRI is a physical parameter of the instrument
and the nonlinearity of up to 2 K at 10 GHz is mainly introduced by higher-order harmonic during detection. The nonlinear brightness temperature calculated using the t-test distribution method is improved by approximately 0.04 K with better fitting results than the ground tests
especially at 10 GHz.
According to the results presented in this study
the nonlinear parameter is independent of observed brightness temperatures
and its nonlinearity is correlated to the instrument’s working condition. The proposed algorithm using the t-test distribution method can improve the nonlinearity fitting results and calibration precision. This method provides accurate nonlinear parameter for on-orbit calibration and can play a role in the total life cycle of MWRI after being launched.
An D W , Gu S Y , Yang Z D and Chen W X . 2016 . On-orbit radiometric calibration for nonlinear of FY- 3 C MWTS. Journal of Infrared and Millimeter Waves , 35 ( 3 ): 317 - 321
安大伟 , 谷松岩 , 杨忠东 , 陈文新 . 2016 . FY-3C微波温度计在轨辐射非线性定标新方法 . 红外与毫米波学报 , 35 ( 3 ): 317-321 [ DOI: 10.11972/j.issn.1001-9014.2016.03.011 http://dx.doi.org/10.11972/j.issn.1001-9014.2016.03.011 ]
Chen W Y , Wang Y , Li X , Xing R X and Liu G F . 2016 . The test system, method and results analysis of the vacuum calibration test of microwave radiation imager . Journal of Microwaves , 32 ( S2 ): 544 - 547
陈卫英 , 王芸 , 李雪 , 邢瑞先 , 刘高峰 . 2016 . 微波成像仪真空定标试验系统、方法和结果分析 . 微波学报 , 32 ( S2 ): 544 - 547
Fei Y T . 2015 . Error Method and Data Processing . 7th ed . Beijing : China Machine Press
费业泰 . 2015 . 误差理论与数据处理 . 7版 . 北京 : 机械工业出版社
Hardy W N . 1973 . Precision temperature reference for microwave radiometry (Short Papers) . IEEE Transactions on Microwave Theory and Techniques , 21 ( 3 ): 149 - 150 [ DOI: 10.1109/TMTT.1973.1127954 http://dx.doi.org/10.1109/TMTT.1973.1127954 ]
Hollinger J P , Peirce J L and Poe G A . 1990 . SSM/I instrument evaluation . IEEE Transactions on Geoscience and Remote Sensing , 28 ( 5 ): 781 - 790 [ DOI: 10.1109/36.58964 http://dx.doi.org/10.1109/36.58964 ]
JPL . 2012 . AIRS Project . Algorithm Theoretical Basis Document. Level 1 b, Part 3: Microwave Instruments.[s.l.]: JPL
Liu G F , Wu S L , Chen W Y , Pan L and He J K . 2014 . Calibration system and achievement of microwave radiation imager of FY- 3 satellite. Journal of Microwaves , 30 ( S1 ): 576 - 579
刘高峰 , 武胜利 , 陈卫英 , 潘莉 , 何嘉恺 . 2014 . FY-3卫星微波成像仪定标系统及实现 . 微波学报 , 30 ( S1 ): 576-579 [ DOI: 10.14183/j.cnki.1005-6122.2014.s1.164 http://dx.doi.org/10.14183/j.cnki.1005-6122.2014.s1.164 ]
Liu X . 2009 . Design and Application of the Sapceborne Microwave Radiometer . Shanghai : Shanghai Jian Tong University
刘新 . 2009 . 星载微波辐射计的设计及应用 . 上海 : 上海交通大学
Peng S S and Li X G . 1997 . Study on the calibration method of 8mm measuring radiometer . Journal of Infrared and Millimeter Waves , 16 ( 4 ): 279 - 284
彭树生 , 李兴国 . 1997 . 8mm测量辐射计定标方法的研究 . 红外与毫米波学报 , 16 ( 4 ): 279 - 284
Precipitation Processing System (PPS) . 2006 . NASA Global Precipitation Measurement Microwave Imager Level 1 B Algorithm Theoretical Basis Document Version 2 . 3 . NASA’ s GODDARD Space Flight Center
Qiao Mu , Yang Hu , He Jiakai and Lyu Liqing . 2012 . On-orbit performanece stability analysis of microwave radiometer imager onboard FY-3 Satellite [J]. Journal of Remote Sensing , 16 ( 6 ): 1246 - 1261
乔木 , 杨虎 , 何嘉恺 , 吕利清 . 2012,风云三号卫星微波成像仪在轨性能稳定性分析 [J]. 遥感学报 , 16 ( 6 ): 1246 - 1261
Ulaby F T , Moore R K and Feng J C . 1988 . Microwave Remote Sensing (Volume I) Microwave Remote Sensing Fundamentals and Radiometry. Hou S C and Ma X G, trans. Beijing: Science Press (F T . 乌拉比, RK穆尔, 冯健超 . 1988 . 微波遥感(第一卷): 微波遥感基础和辐射测量学. 侯世昌, 马锡冠, 译 . 北京: 科学出版社)
Xiao Z H , Zhang Z Y and Guo W . 2000 . A review: the calibration of ground-based, airborne and satellite-borne microwave radiometers . Remote Sensing Technology and Application , 15 ( 2 ): 113 - 120
肖志辉 , 张祖荫 , 郭伟 . 2000 . 地基、空基、星基微波辐射计定标技术概览 . 遥感技术与应用 , 15 ( 2 ): 113-120 [ DOI: 10.3969/j.issn.1004-0323.2000.02.011 http://dx.doi.org/10.3969/j.issn.1004-0323.2000.02.011 ]
Yang H , Weng F Z , Lv L Q , Lu N M , Liu G F , Bai M , Qian Q Y , He J K and Xu H X . 2011 . The FengYun-3 microwave radiation imager on-orbit verification . IEEE Transactions on Geoscience and Remote Sensing , 49 ( 11 ): 4552 - 4560 [ DOI: 10.1109/TGRS.2011.2148200 http://dx.doi.org/10.1109/TGRS.2011.2148200 ]
Ye H . 2012 . Calibration and Error Analysis of Microwave Radiometer . Wuhan : Huazhong University of Science and Technology
叶辉 . 2012 . 微波辐射计定标与误差分析 . 武汉 : 华中科技大学
Zhang Miao , Wang Sujuan , Qin Danyu , Qiu Hong and Tang Shihao . 2018 . The inversion and quality validation of FY-3C MWRI sea surface temperature [J]. Journal of Remote Sensing , 22 ( 5 ): 713 - 722 .
张淼 ， 王素娟 ， 覃丹宇 ， 邱红 ， 唐世浩 . 2018 . FY-3C微波成像仪海面温度产品算法及精度检验 [J]. 遥感学报 ， 22 ( 5 ): 713 - 722
相关作者
相关机构
京公网安备11010802024621
