Google Earth Engine ——数据全解析专辑（COPERNICUS/S5P/NRTI/L3_CLOUD）云参数实时高分辨率数据集

此星光明

发布于 2024-02-02 09:01:47

1430

发布于 2024-02-02 09:01:47

NRTI/L3_CLOUD

This dataset provides near real-time high-resolution imagery of cloud parameters.

The TROPOMI/S5P cloud properties retrieval is based on the OCRA and ROCINN algorithms currently being used in the operational GOME and GOME-2 products. OCRA retrieves the cloud fraction using measurements in the UV/VIS spectral regions and ROCINN retrieves the cloud height (pressure) and optical thickness (albedo) using measurements in and around the oxygen A-band at 760 nm. Version 3.0 of the algorithms are used, which are based on a more realistic treatment of clouds as optically uniform layers of light-scattering particles. Additionally, the cloud parameters are also provided for a cloud model which assumes the cloud to be a Lambertian reflecting boundary. [More information]

该数据集提供了云参数的近实时高分辨率图像。

TROPOMI/S5P 云属性检索基于目前在运营的 GOME 和 GOME-2 产品中使用的 OCRA 和 ROCINN 算法。 OCRA 使用 UV/VIS 光谱区域中的测量值来检索云分数，ROCINN 使用 760 nm 氧 A 波段内和周围的测量值来检索云高度（压力）和光学厚度（反照率）。使用了 3.0 版算法，该算法基于将云视为光散射粒子的光学均匀层的更真实处理。此外，还为假设云是朗伯反射边界的云模型提供了云参数。

NRTI L3 Product

为了制作我们的 NRTI L3 产品，我们使用 harpconvert 对数据进行网格化。

To make our NRTI L3 products, we use harpconvert to grid the data.

Example harpconvert invocation for one tile:

harpconvert --format hdf5 --hdf5-compression 9
-a 'cloud_fraction>50;derive(datetime_stop {time});
bin_spatial(2001, 50.000000, 0.01, 2001, -120.000000, 0.01);
keep(cloud_fraction,cloud_top_pressure,cloud_top_height,
cloud_base_pressure,cloud_base_height,cloud_optical_depth,surface_albedo,
sensor_azimuth_angle,sensor_zenith_angle,solar_azimuth_angle,
solar_zenith_angle)'
S5P_NRTI_L2__CLOUD__20190208T230503_20190208T231003_06860_01_010105_20190209T005255.nc
output.h5

Assets between the dates 2018-07-10 and 2018-07-18 are missing due to non-standard structure of product files.

Dataset Availability

2018-07-05T23:24:16 - 2021-09-05T00:00:00

Dataset Provider

European Union/ESA/Copernicus

Collection Snippet

ee.ImageCollection("COPERNICUS/S5P/NRTI/L3_CLOUD")

Resolution

0.01 degrees

Bands Table

Name	Description	Min*	Max*	Units
cloud_fraction	Retrieved effective radiometric cloud fraction	0	1	fraction
cloud_top_pressure	Retrieved atmospheric pressure at the level of cloud top	12109	101299	Pa
cloud_top_height	Retrieved altitude of the cloud top	9	15471	m
cloud_base_pressure	Cloud base pressure	14169	101299	Pa
cloud_base_height	Cloud base height	9	14545	m
cloud_optical_depth	Retrieved cloud optical depth	1	250	m
surface_albedo	Surface albedo	0	1
sensor_azimuth_angle	Azimuth angle of the satellite at the ground pixel location (WGS84); angle measured East-of-North.	-180	180	degrees
sensor_zenith_angle	Zenith angle of the satellite at the ground pixel location (WGS84); angle measured away from the vertical.	0.09	67	degrees
solar_azimuth_angle	Azimuth angle of the Sun at the ground pixel location (WGS84); angle measured East-of-North.	-180	180	degrees
solar_zenith_angle	Zenith angle of the satellite at the ground pixel location (WGS84); angle measured away from the vertical.	8	80	degrees

* = Values are estimated

影像属性：

Name	Type	Description
ALGORITHM_VERSION	String	The algorithm version used in L2 processing. It's separate from the processor (framework) version, to accommodate different release schedules for different products.
BUILD_DATE	String	The date, expressed as milliseconds since 1 Jan 1970, when the software used to perform L2 processing was built.
HARP_VERSION	Int	The version of the HARP tool used to grid the L2 data into an L3 product.
INSTITUTION	String	The institution where data processing from L1 to L2 was performed.
L3_PROCESSING_TIME	Int	The date, expressed as milliseconds since 1 Jan 1970, when Google processed the L2 data into L3 using harpconvert.
LAT_MAX	Double	The maximum latitude of the asset (degrees).
LAT_MIN	Double	The minimum latitude of the asset (degrees).
LON_MAX	Double	The maximum longitude of the asset (degrees).
LON_MIN	Double	The minimum longitude of the asset (degrees).
ORBIT	Int	The orbit number of the satellite when the data was acquired.
PLATFORM	String	Name of the platform which acquired the data.
PROCESSING_STATUS	String	The processing status of the product on a global level, mainly based on the availability of auxiliary input data. Possible values are "Nominal" and "Degraded".
PROCESSOR_VERSION	String	The version of the software used for L2 processing, as a string of the form "major.minor.patch".
PRODUCT_ID	String	Id of the L2 product used to generate this asset.
PRODUCT_QUALITY	String	Indicator that specifies whether the product quality is degraded or not. Allowed values are "Degraded" and "Nominal".
SENSOR	String	Name of the sensor which acquired the data.
SPATIAL_RESOLUTION	String	Spatial resolution at nadir. For most products this is `3.5x7km2`, except for `L2__O3__PR`, which uses `28x21km2`, and `L2__CO____` and `L2__CH4___`, which both use `7x7km2`. This attribute originates from the CCI standard.
TIME_REFERENCE_DAYS_SINCE_1950	Int	Days from 1 Jan 1950 to when the data was acquired.
TIME_REFERENCE_JULIAN_DAY	Double	The Julian day number when the data was acquired.
TRACKING_ID	String	UUID for the L2 product file.
CLOUD_MODE	String	Tells which model was used to generate this dataset, the CAL (Clouds As Layers) model or the CRB (Clouds as Reflecting Boundaries) model. Valid values of this property are "cal" or "crb", respectively, with "cal" being the default.
STATUS_MET_2D	String	This dataset uses some dynamic auxiliary data from the European Centre for Medium-Range Weather Forecasts. If the ECMWF data was used, this field will have the value 'Nominal'. If the ECMWF data was not used, a fallback solution was used, and this field will have the value of "Fallback".

代码：

var collection = ee.ImageCollection('COPERNICUS/S5P/NRTI/L3_CLOUD')
  .select('cloud_fraction')
  .filterDate('2019-06-01', '2019-06-02');

var band_viz = {
  min: 0,
  max: 0.95,
  palette: ['black', 'blue', 'purple', 'cyan', 'green', 'yellow', 'red']
};

Map.addLayer(collection.mean(), band_viz, 'S5P Cloud');
Map.setCenter(-58.14, -10.47, 2);

影像：