Google Earth Engine（GEE）——NOAA CDR GRIDSAT-B1資料集介紹（靜止衛星的全球紅外測量的高品質氣候資料）

This dataset provides a high quality Climate Data Record (CDR) of global infrared measurements from geostationary satellites.

The geostationary satellite data (GridSat-B1) provides data from 3 channels: the CDR-quality infrared window (IRWIN) channel (near 11μm), the visible channel (near 0.6μm) and the infrared water vapor (IRWVP) channel (near 6.7μm). The GridSat-B1 data is projected onto a global 0.07 degree latitude equal-angle grid with date coverage spanning from 1980-present. This data is sourced from the 3-hourly International Satellite Cloud Climatology Project (ISCCP) B1 data. The satellites included in this dataset with their longitudinal coverage over time can be seen ​​here​​. In regions of overlap the CDR methodology merges satellites by selecting the nadir-most observations for each grid point.

Notes:

• Mappings from satid to satellite name are contained in the image's properties as satid_number: "satellite_name", e.g. satid_0: GOES-13, satid_1: GOES-15, and satid_2: GOES-16.
• IRWIN data has been corrected for view zenith angle, but this correction is not perfect. It also treats all satellites the same way, whereas the view zenith angle dependence will vary by satellite. Some VZA residual will be apparent.
• IRWVP data has no view zenith angle correction and is not CDR quality.
• VSCHN data has no view zenith angle corrections and is not CDR quality.
• Removing the View Zenigth Angle correction for the IRWIN channels can be done with the following: Original_temperature_observed = irwin_cdr - irwin_vza_adj

該資料集提供了來自靜止衛星的全球紅外測量的高品質氣候資料記錄（CDR）。

地球靜止衛星資料（GridSat-B1）提供了3個頻道的資料：CDR品質的紅外視窗（IRWIN）頻道（接近11μm），可見光頻道（接近0.6μm）和紅外水汽（IRWVP）頻道（接近6.7μm）。GridSat-B1的資料被投射到一個全球0.07度緯度的等角網格上，日期覆寫從1980年至今。該資料來自于每3小時一次的國際衛星雲霧學項目（ISCCP）B1資料。該資料集所包含的衛星及其縱向覆寫範圍可以在這裡看到。在重疊的區域，CDR方法通過選擇每個網格點的最底線的觀測資料來合并衛星。

notes:

從satid到衛星名稱的映射包含在圖像的屬性中，如satid_number: "satellite_name"，例如satid_0: GOES-13, satid_1: GOES-15, satid_2: GOES-16。

IRWIN資料已經對視圖天頂角進行了校正，但這種校正并不完美。它對所有衛星的處理方式也是一樣的，而視線天頂角的依賴性會因衛星而異。一些VZA殘餘将是明顯的。

IRWVP資料沒有視區天頂角校正，不符合CDR品質。

VSCHN資料沒有視圖天頂角校正，不是CDR品質。

移除IRWIN通道的視圖天頂角校正可以通過以下方式完成。Original_temperature_observed = irwin_cdr - irwin_vza_adj

Dataset Availability時間

1980-01-01T00:00:00 -

Dataset Provider資料提供者

​​NOAA​​

Collection Snippet

​

​ee.ImageCollection("NOAA/CDR/GRIDSAT-B1/V2")​

​

波段：

Resolution

7792 meters

Bands Table

Name	Description	Min*	Max*	Units	Scale	Offset
irwin_cdr	Brightness temperature near 11μm, nadir-most observation	-2093	13615	K	0.01	200
irwin_2	Brightness temperature near 11μm, second-best observation (based on view zenith angle)	-4123	13579	K	0.01	200
irwin_3	Brightness temperature, third-best observation based on view zenith angle	-1624	14240	K	0.01	200
irwvp	Brightness temperature near 6.7μm, nadir-most observation	-5907	10219	K	0.01	200
irwvp_2	Brightness temperature near 6.7μm, second-best observation based on view zenith angle	-5081	10260	K	0.01	200
vschn	Visible reflectance near 0.6μm, nadir-most observation	-25000	4275	0.00004	1
vschn_2	Visible reflectance near 0.6μm, second-best observation based on view zenith angle	-25000	3800	0.00004	1
irwin_vza_adj	Adjustment made to all IRWIN channels. Provided to allow users to reverse the view zenith correction for the irwin_cdr variable.	36	171	K	0.25	-10
satid_ir1	satid values for irwin_cdr. For this and other satid bands, the mappings of satid to satellite name are given in the properties for each image	5
satid_ir2	satid values per pixel for irwin_2	5
satid_ir3	satid values per pixel for irwin_3	5
satid_wv1	satid values per pixel for irwvp	5
satid_wv2	satid values per pixel for irwvp2	5
satid_vs1	satid values per pixel for vischn	5
satid_vs2	satid values per pixel for vischn2	5

* = Values are estimated

影像屬性：

Name	Type	Description
satid_0	String	Satellite name (see notes)
satid_1	String	Satellite name (see notes)
satid_2	String	Satellite name (see notes)
satid_3	String	Satellite name (see notes)
satid_4	String	Satellite name (see notes)
satid_5	String	Satellite name (see notes)

資料說明：

The NOAA CDR Program\u2019s official distribution point for CDRs is NOAA\u2019s National Climatic Data Center which provides sustained, open access and active data management of the CDR packages and related information in keeping with the United States\u2019 open data policies and practices as described in the President's Memorandum on "Open Data Policy" and pursuant to the Executive Order of May 9, 2013, "Making Open and Machine Readable the New Default for Government Information". In line with these policies, the CDR data sets are nonproprietary, publicly available, and no restrictions are placed upon their use.

For more information, see the 這個式資料官方的使用手冊​​Fair Use of NOAA's CDR Data Sets, Algorithms and Documentation​​ pdf. 

資料引用：

Kenneth R. Knapp, and NOAA CDR Program (2014): NOAA Climate Data Record (CDR) of Gridded Satellite Data from ISCCP B1 (GridSat-B1) 11 micron Brightness Temperature, Version 2. [indicate subset used]. NOAA National Climatic Data Center. ​​doi:10.7289/V59P2ZKR​​ [access date].

Knapp, K. R., S. Ansari, C. L. Bain, M. A. Bourassa, M. J. Dickinson, C. Funk, C. N. Helms, C. C. Hennon, C. D. Holmes, G. J. Huffman, J. P. Kossin, H.-T. Lee, A. Loew, and G. Magnusdottir, 2011: Globally gridded satellite (GridSat) observations for climate studies. Bulletin of the American Meteorological Society, 92, 893-907. ​​doi:10.1175/2011BAMS3039.1​​

 代碼： 

var dataset = ee.ImageCollection('NOAA/CDR/GRIDSAT-B1/V2')
                  .filter(ee.Filter.date('2017-05-01', '2017-05-14'));
var brightnessTemp = dataset.select(['irwin_cdr', 'vschn', 'irwvp']);
var brightnessTempVis = {
  min: 500.0,
  max: 10000.0,
};
Map.setCenter(7.71, 17.93, 2);
Map.addLayer(brightnessTemp, brightnessTempVis, 'Brightness Temperature');