Sentinel-5P L2
About Sentinel-5P Data
Sentinel Hub supports Sentinel-5P level 2 (L2) data products as provided by ESA. General information about the satellite and specifically Level 2 data is available here: https://sentinels.copernicus.eu/web/sentinel/data-products. Raw bands (Level 1 products) are not available in Sentinel Hub.
Learn more about Sentinel-5P atmosphere monitoring by reading our blog post on measuring Air Pollution from space.
Mission Information
The Sentinel-5P (P for precursor) mission aims at providing information and services on air quality and climate between 2017 and at least 2023. With the TROPOMI sensor on board it makes daily global observations of key atmospheric constituents, including ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, methane, formaldehyde as well as cloud and aerosol properties. The mission aims at ensuring data continuity between the retirement of the Envisat satellite and NASA's Aura mission and the launch of Sentinel-5 (source: ESA).
Basic Facts
| Property | Info |
|---|---|
| Spatial resolution | Up to 5.5* km x 3.5 km. |
| Sensor | Tropospheric Monitoring Instrument (TROPOMI), a spectrometer measuring ultraviolet and visible (270–495 nm), near infrared (675–775 nm) and shortwave infrared (2305–2385 nm) light. |
| Revisit time | Less than one day. |
| Spatial coverage | Global coverage. |
| Data availability | Since April 2018. |
| Common usage/purpose | To provide global information on a multitude of atmospheric trace gases, aerosols and cloud distributions affecting air quality and climate. |
(Source: ESA.)
* "5.5 x 3.5" means a spatial resolution of 5.5 km in the satellite flight direction and 3.5 km in the perpendicular direction at nadir. Data released before 6 August 2019 had a resolution in the flight direction up to 7 km ( see ESA news).
Attribution and Use
EU law grants free access to Copernicus Sentinel Data and Service Information for the purpose of the following use in so far as it is lawful: a) reproduction; b) distribution; c) communication to the public; d) adaptation, modification and combination with other data and information; e) any combination of points a to d.
See more details on the use of Copernicus Sentinel data and service information here. Tracing based on Sentinel imagery is allowed for commercial purposes as well.
Acknowledgment or credit: Contains modified Copernicus Sentinel data [Year] processed by Sentinel Hub
Accessing Sentinel-5P Data
To access data you need to send a POST request to our process API. The requested data will be returned as the response to your request. Each POST request can be tailored to get you exactly the data you require. To do this requires setting various parameters which depend on the datasource you are querying. This chapter will help you understand the parameters for S5PL2 data. To see examples of such requests go here, and for an overview of all API parameters see the API Reference.
Endpoint Locations
| Service | Notes |
|---|---|
| creodias.sentinel-hub.com/api/ | Global coverage since May 2018 |
Data type identifier: sentinel-5p-l2
Use sentinel-5p-l2 (previously S5PL2) as the value of the input.data.type parameter in your API requests. This is mandatory and will ensure you get Sentinel-5P L2 data.
Filtering Options
This chapter will explain the input.data.dataFilter object of the S5PL2 process API.
timeRange
For simple mosaicking, the time range which is requested is clipped to start at most 24 hours before the to date-time. The reason for this is that Sentinel-5P covers the globe in one day therefore longer time ranges are not neccessary. The limitation also improves the responsiveness of Sentinel Hub.
mosaickingOrder
Sets the order of sources from which the output result is mosaicked. If there are multiple sources available for the same time, unless explicitly set otherwise, Sentinel Hub will take the source with the slowest timeliness (i.e. RPRO prefered to OFFL prefered to NRTI).
| Value | Description |
|---|---|
| mostRecent | the pixel will be selected from the tile, which was acquired most recently |
| leastRecent | similar to mostRecent but in reverse order |
timeliness
You can force the timeliness of the requested data. If not set and there are multiple sources available for the same time, Sentinel Hub will take the source with the slowest timeliness (RPRO prefered to OFFL prefered to NRTI). To explicitly set, the options are:
- NRTI for near realtime,
- OFFL for offline,
- RPRO for reprocessing.
Processing Options
This chapter will explain the input.data.processing object of the S5PL2 process API.
| Parameter | Description | Values | Default |
|---|---|---|---|
| upsampling | Defines the interpolation used for processing, regardless of the resolution | NEAREST - nearest neighbour interpolation BILINEAR - bilinear interpolation BICUBIC - bicubic interpolation | NEAREST |
| downsampling | Not used, use upsampling instead | N/A | Ignored |
| minQa | Sentinel-5P data is flagged with quality values (“qa_value”). minQa is the minimum (inclusive) pixel quality to be displayed in percent. For example, setting minQa = 75 will only display pixels with qa_value >= 75% | Values between 0 and 100. | 75 For NO2 50 for other products |
Available Bands and Data
Information in this chapter is useful when defining input object in evalscript: any string listed in the column Name can be an element of the input.bands array in your evalscript.
| Name | Description |
|---|---|
| CO | Carbon monoxide, more. |
| HCHO | Formaldehyde, more. |
| NO2 | Nitrogen oxide, more. |
| O3 | Ozone, more. |
| SO2 | Sulphur dioxide, more. |
| CH4 | Methane, more. |
| AER_AI_340_380 | UV (Ultraviolet) Aerosol Index calculated based on wavelengths of 340 nm and 380 nm. More. |
| AER_AI_354_388 | UV (Ultraviolet) Aerosol Index calculated based on wavelengths of 354 nm and 388 nm. More. |
| CLOUD_BASE_PRESSURE | Cloud base pressure, more. |
| CLOUD_TOP_PRESSURE | Cloud top pressure, more. |
| CLOUD_BASE_HEIGHT | Cloud base height, more. |
| CLOUD_TOP_HEIGHT | Cloud top height, more. |
| CLOUD_OPTICAL_THICKNESS | Cloud optical thickness, more. |
| CLOUD_FRACTION | Effective radiometric cloud fraction, more. |
| dataMask | The mask of data/no data pixels, more. |
Units
The data values for each band in your custom script are presented in the units as specified here. In case more than one unit is available for a given band, you may optionally set the value of input.units in your evalscript setup function to one of the values in the Sentinel Hub Units column. Doing so will present data in that unit. The Sentinel Hub units parameter combines the physical quantity and corresponding units of measurement values. As such, some names more closely resemble physical quantities, others resemble units of measurement.
The Source Format specifies how and with what precision the digital numbers (DN) from which the unit is derived are encoded. Bands requested in DN units contain exactly the pixel values of the source data. Note that resampling may produce interpolated values. DN is also used whenever a band is derived computationally (like dataMask); such bands can be identified by having DN units and N/A source format. DN values are typically not offered if they do not simply represent any physical quantity, in particular, when DN values require source-specific (i.e. non-global) conversion to physical quantities.
Values in non-DN units are computed from the source (DN) values with at least float32 precision. Note that the conversion might be nonlinear, therefore the full value range and quantization step size of such a band can be hard to predict. Band values in evalscripts always behave as floating point numbers, regardless of the actual precision.
The Typical Range indicates what values are common for a given band and unit, however outliers can be expected.
| Product/Band | Physical Quantity (units) | Sentinel Hub Units | Source Format | Typical Range | Notes |
|---|---|---|---|---|---|
| CO | Carbon monoxide total column (mol/m2) | MOL_M2 | FLOAT32 | 0 - 0.1 | Certain events (wildfires) may cause these limits to be exceeded. |
| HCHO | Formaldehyde troposheric vertical column (mol/m2) | MOL_M2 | FLOAT32 | 0 - 0.001 | Certain events (wildfires) may cause these limits to be exceeded. |
| NO2 | Nitrogen dioxide tropospheric column (mol/m2) | MOL_M2 | FLOAT32 | 0 - 0.0003 | Peak values for polluted cities may reach two or three times the upper value. |
| O3 | Ozone total column (mol/m2) | MOL_M2 | FLOAT32 | 0 - 0.36 | |
| SO2 | Sulfur dioxide total column (mol/m2) | MOL_M2 | FLOAT32 | 0 - 0.01 | Explosive volcanic eruptions can exceed 0.35 mol/m2 and instrumental noise can produce negative values. |
| CH4 | Column averaged dry air mixing ratio of methane (parts per billion) | PPB | FLOAT32 | 1,600 - 2,000 | |
| AER_AI_340_380 | UV aerosol index from 380 and 340 nm (unitless) | INDEX | FLOAT32 | -1 - 5 | |
| AER_AI_354_388 | UV aerosol index from 388 and 354 nm (unitless) | INDEX | FLOAT32 | -1 - 5 | |
| CLOUD_BASE_PRESSURE | Cloud base pressure (pascals) | PASCALS | FLOAT32 | 1,000 - 110,000 | |
| CLOUD_TOP_PRESSURE | Cloud top pressure (pascals) | PASCALS | FLOAT32 | 1,000 - 110,000 | |
| CLOUD_BASE_HEIGHT | Cloud base height (meters) | METERS | FLOAT32 | 0 - 20,000 | |
| CLOUD_TOP_HEIGHT | Cloud top height (meters) | METERS | FLOAT32 | 0 - 20,000 | |
| CLOUD_OPTICAL_THICKNESS | Cloud optical thickness (unitless) | OPTICAL_DEPTH | FLOAT32 | 0 - 250 | |
| CLOUD_FRACTION | Effective radiometric cloud fraction (unitless) | FRACTION | FLOAT32 | 0 - 1 | |
| dataMask | N/A | DN | N/A | 0 - no data 1 - data |
Mosaicking
SIMPLE and ORBIT mosaicking types are supported.
Scenes Object
scenes object stores metadata. An example of metadata available in scenes object for Sentinel-5p L2 when mosaicking is ORBIT:
| Property name | Value |
|---|---|
| tiles[i].date | '2018-12-30T10:43:00Z' |
| tiles[i].shId | 1900340 |
| tiles[i].dataPath | 'http://data.cloudferro.com/EODATA/Sentinel-5P/TROPOMI/L2__CO____/2018/12/30/S5P_OFFL_L2__CO_____20181230T104300_20181230T122430_06286_01_010202_20190105T100707/S5P_OFFL_L2__CO_____20181230T104300_20181230T122430_06286_01_010202_20190105T100707.nc' |
Properties of a scenes object can differ depending on the selected mosaicking and in which evalscript function the object is accessed. Working with metadata in evalscript user guide explains all details and provide examples.
Collection Specific Constraints
The raw data is encoded as 32-bit float samples. For scientific usage it is best to set tiff as an output format and sampleType: SampleType.FLOAT32.
Sentinel-5P data can potentially contain many no data pixels which is a consequence of the way it is measured. We therefore suggest using the dataMask band to differentiate between actual zero values and no data.
Catalog API Capabilities
To access Sentinel 5P L2 product metadata you need to send search request to our Catalog API. The requested metadata will be returned as JSON formatted response to your request.
Collection identifier: sentinel-5p-l2
Filter extension
sat:absolute_orbits5p:timeliness(possible values)s5p:type(possible values:O3,O3_TCL,O3_PR,O3_TPR,NO2,SO2,CO,CH4,HCHO,CLOUD,AER_AI,AER_LH,FRESCO,BD3,BD6,BD7)
Distinct extension
dates5p:type