中国SMMR数据集主要是使用Nimbus-7卫星携带的扫描式多通道微波辐射计(SMMR)获得的微波亮度温度（TB)数据。包含1978~1987年的06H、06V、10H、10V、18H、18V、21H、21V、37H、37V十个通道的每天两次（升轨&降轨）亮度温度，其中H代表水平极化，V代表垂直极化。
\n\n1978年10月发射的雨云Nimbus-7太阳同步极轨卫星，搭载着微波传感器SMMR，是一台测量地表辐射的五个频率十通道的双极化微波辐射计。它以约50.3°固定入射角扫描地表，幅宽780km，并在正午12：00（升轨）与午夜24：00（降轨）通过赤道。SMMR时间分辨率为每日，但是每隔5—6天才重访同一地表一次。其特征值见下表。
\n\nSMMR若干特征值
\n\n通道 频率（GHz） 空间分辨率（km） 温度分辨（K）天线波速宽（deg）
\n\n37V/H 37.00 30 1.5 0.8
\n\n21V/H 21.00 60 1.5 1.4
\n\n18V/H 18.00 60 1.2 1.6
\n\n10V/H 10.69 97.5 0.9 2.6
\n\n6V/H 6.60 156 0.9 4.2
\n\n1、文件格式和命名：
\n\n每组数据均由遥感数据文件，.JPG图像文件和.met辅助信息文件，以及.TIM时间信息文件和相应的.met时间信息辅助文件构成。
\n\nSMMR_Grid_China目录下的每组数据文件名及命名规则如下：
\n\nChina-EASE-N07-ML/HaaaabbbA/D.ccH/V（遥感数据）China-EASE-N07-ML/HaaaabbbA/D.ccH/V.jpg （图像文件）
\n\nChina-EASE-N07-ML/HaaaabbbA/D.ccH/V.met（辅助信息文件）
\n\nChina-EASE-N07-ML/HaaaabbbA/D.TIM （时间信息文件）China-EASE-N07-ML/HaaaabbbA/D.TIM.met （时间信息辅助文件）。
\n\n2、坐标系及投影：
\n\n投影方式为等积割圆柱投影，双标准纬线为南北纬30度。有关EASE-GRID的相关详细信息，请参考http://www.ncgia.ucsb.edu/globalgrids-book/ease_grid/。
\n\n如果需要将EASE-Grid投影方式转换成Geographic投影方式，请参照ease2geo.prj文件，内容如下：
\n\nInput
\n\nprojection cylindrical
\n\nunits meters
\n\nparameters 6371228 6371228
\n\n1 /* Enter projection type (1, 2, or 3)
\n\n0 00 00 /* Longitude of central meridian
\n\n30 00 00 /* Latitude of standard parallel
\n\nOutput
\n\nProjection GEOGRAPHIC
\n\nSpheroid KRASovsky
\n\nUnits dd
\n\nparameters
\n\nend
\n\n3、数据格式：
\n\n以整数形二进制存储，每个数据占2个字节。本数据集中实际存储的数据为亮温*10，读出数据后需除以10得到真实亮温。
\n\n空间分辨率：25km，12.5km (SSM/I 85GHz)；
\n\n时间分辨率：逐日，从1978年至2007年。
\n\n4、空间范围：
\n\n经度：60°-140°东经；
\n\n纬度：15°-55°北纬。
\n\n5、数据读取
\n\n每一组数据包括遥感影像数据文件，.JPG图像文件和.met辅助信息文件，其中JPG文件可以用Windows图片和传真查看器打开，.met辅助信息文件可以用记事本打开，遥感影像数据文件可以在ENVI和ERDAS软件中打开。
", "ds_source": "自主生产，人工采集
", "ds_process_way": "数据集通过严格的人工审核控制质量
", "ds_quality": "本数据经过人工校正、质量良好
", "ds_acq_start_time": "1978-10-25 00:00:00", "ds_acq_end_time": "1987-08-20 00:00:00", "ds_acq_place": "中国", "ds_acq_lon_east": 135.5, "ds_acq_lat_south": 17.766666666666666, "ds_acq_lon_west": 73.19972222222222, "ds_acq_lat_north": 53.86638888888889, "ds_acq_alt_low": null, "ds_acq_alt_high": null, "ds_share_type": "login-access", "ds_total_size": 1035145142, "ds_files_count": 3, "ds_format": "栅格", "ds_space_res": "25000.0m", "ds_time_res": "日", "ds_coordinate": "WGS84", "ds_projection": "EASE-GRID", "ds_thumbnail": "6c62a54a-462f-4f1c-a1c6-e48619f166a5.png", "ds_thumb_from": 0, "ds_ref_way": "", "paper_ref_way": "", "ds_ref_instruction": "None", "ds_from_station": null, "organization_id": "9c4867b1-5cb1-4de0-abeb-df42547bf41e", "ds_serv_man": "李红星 ", "ds_serv_phone": "0931-4967287", "ds_serv_mail": "ncdc@lzb.ac.cn", "doi_value": "", "subject_codes": [ "170.4510" ], "quality_level": 3, "publish_time": "2020-03-26 17:32:54", "last_updated": "2023-09-04 13:40:20", "protected": false, "protected_to": null, "lang": "zh", "cstr": "11738.11.ncdc.Westdc.2020.348", "i18n": { "en": { "title": "Brightness and temperature data set of passive microwave SMMR in China", "ds_format": "Raster", "ds_source": "Self production, manual collection
", "ds_quality": "The data has been corrected manually and the quality is good
", "ds_ref_way": "", "ds_abstract": "China's SMMR data set mainly uses the microwave brightness temperature (TB) data obtained by scanning multichannel microwave radiometer (SMMR) carried by nimbus-7 satellite. It includes the brightness temperature of 06h, 06v, 10h, 10V, 18h, 18V, 21h, 21V, 37h and 37V channels from 1978 to 1987. H represents horizontal polarization and V represents vertical polarization.
\nThe nimbus-7 solar synchronous polar orbit satellite, launched in October 1978, is a dual polarization microwave radiometer with five frequencies and ten channels for measuring surface radiation, which is equipped with a microwave sensor SMMR. It scans the earth's surface at a fixed angle of incidence of about 50.3 ° with a width of 780km and passes through the equator at 12:00 noon (ascending orbit) and 24:00 midnight (descending orbit). The time resolution of SMMR is daily, but the same surface is revisited every 5-6 days. The characteristic values are shown in the table below.
\nSome eigenvalues of SMMR
\nChannel frequency (GHz) spatial resolution (km) temperature resolution (k) antenna wave velocity width (DEG)
\n37V/H 37.00 30 1.5 0.8
\n21V/H 21.00 60 1.5 1.4
\n18V/H 18.00 60 1.2 1.6
\n10V/H 10.69 97.5 0.9 2.6
\n6V/H 6.60 156 0.9 4.2
\n1. File format and naming:
\nEach group of data consists of remote sensing data file,. JPG image file,. Met auxiliary information file,. Tim time information file and corresponding. Met auxiliary time information file.
\nThe file names and naming rules of each group of data under SMMR grid China directory are as follows:
\nChina-ease-n07-ml / haaaabbba / d.cch/v (remote sensing data) china-ease-n07-ml / haaaabbba / d.cch/v.jpg (image file)
\nChina-ease-n07-ml / haaaabbba / d.cch/v.met (auxiliary information file)
\nChina-ease-n07-ml / haaaabbba / d.tim (time information file) china-ease-n07-ml / haaaabbba / d.tim.met (time information auxiliary file).
\n2. Coordinate system and projection:
\nThe projection mode is equal product cutting cylinder projection, and the double standard latitude is 30 degrees of North-South latitude. For more information about ease-grid, please refer to http://www.ncgia.ucsb.edu/globalgrids-book/ease'grid /.
\nIf you need to convert the ease grid projection mode to the geographic projection mode, please refer to the ease2geo.prj file, as follows:
\nInput
\nprojection cylindrical
\nunits meters
\nparameters 6371228 6371228
\n1 /* Enter projection type (1, 2, or 3)
\n0 00 00 /* Longitude of central meridian
\n30 00 00 /* Latitude of standard parallel
\nOutput
\nProjection GEOGRAPHIC
\nSpheroid KRASovsky
\nUnits dd
\nparameters
\nend
\n3. Data format:
\nIt is stored as an integer binary, and each data takes up 2 bytes. The actual stored data in this data set is light temperature * 10. After reading out the data, divide by 10 to get the real light temperature.
\nSpatial resolution: 25km, 12.5km (SSM / I 85ghz)
\nTime resolution: day by day, from 1978 to 2007.
\n4. Space range:
\nLongitude: 60 ° - 140 ° east longitude
\nLatitude: 15 ° - 55 ° north latitude.
\n5. Data reading
\nEach group of data includes remote sensing image data file,. JPG image file and. Met auxiliary information file. JPG file can be opened with windows picture and Fax Viewer,. Met auxiliary information file can be opened with Notepad, remote sensing image data file can be opened in ENVI and ERDAS software.
", "ds_time_res": "日", "ds_acq_place": "China", "ds_space_res": "25000.0m", "ds_projection": "EASE-GRID", "ds_process_way": "Data set quality control through strict manual audit
", "ds_ref_instruction": "In order to respect intellectual property rights, protect the rights and interests of data authors, expand the services of data centers, and evaluate the application potential of data, data users are requested to clearly indicate the data source and data authors in the research results (including published papers, works, data products and unpublished research reports, data products, etc.) produced by using data. For data reprinted (secondary or multiple releases), the author must also indicate the source of the original data. The data set is provided by cold and arid regions Sciences Data Center at Lanzhou (http://westdc.westgis.ac.cn)" } }, "submit_center_id": "ncdc", "data_level": 0, "license_type": "CC BY 4.0", "doi_reg_from": "reg_local", "cstr_reg_from": "reg_local", "doi_not_reg_reason": null, "cstr_not_reg_reason": null, "is_paper_in_submitting": false, "ds_topic_tags": [ "被动微波", "亮度温度", "SSMR" ], "ds_subject_tags": [ "自然地理学" ], "ds_class_tags": [], "ds_locus_tags": [ "中国" ], "ds_time_tags": [ 1978, 1987 ], "ds_contributors": [ { "true_name": "车涛", "email": "chetao@lzb.ac.cn", "work_for": "中国科学院西北生态环境资源研究院", "country": "中国" }, { "true_name": "晋锐", "email": "jinrui@lzb.ac.cn", "work_for": "中国科学院西北生态环境资源研究院", "country": "中国" } ], "ds_meta_authors": [ { "true_name": "吴立宗", "email": "wulizong@pric.org.cn", "work_for": "国家极地科学数据中心", "country": "中国" } ], "ds_managers": [ { "true_name": "车涛", "email": "chetao@lzb.ac.cn", "work_for": "中国科学院西北生态环境资源研究院", "country": "中国" } ], "category": "遥感及产品" }