EarthCARE level-2 demonstration products from simulated scenes

Overview

The EarthCARE satellite combines four instruments, a Cloud Profiling Radar (CPR), an Atmospheric Lidar (ATLID), a Multispectral Imager (MSI) and a Broadband Radiometer (BBR), from which many products will be generated on the properties of clouds, aerosols, precipitation and radiation.  The dataset in this repository consists of test products generated from simulated 3D scenes produced by the Canadian Global Environmental Multiscale (GEM) model. This includes both Level 1 (L1) "input" products containing simulated satellite measurements, and Level 2 (L2) "output" products produced by running the various European retrieval algorithms on the inputs.  The dataset has been produced as part of the European Space Agency funded "CARDINAL" project involving numerous European and Canadian scientists, and there are several versions representing the evolution of the algorithms during preparation for the launch of EarthCARE.  The scenes and algorithms are discussed in detail in a Special Issue of the journal Atmospheric Modelling Techniques (AMT), so the overview here is limited to a summary of what is contained in this dataset.

Directory structure

The three top-level directories inside the zip file are for the three simulated scenes, each of which represent a single 6000-km long EarthCARE granule:

• Halifax: A swath over the Atlantic Ocean from the Caribbean to the Labrador Sea, passing close to Halifax in Nova Scotia
• Baja: A swath passing over the Rocky Mountains and the Baja California peninsula in Mexico
• Hawaii: A swath over the Pacific Ocean passing close to Hawaii

Each of these directories contains three further directories:

• input: simulated level-1 instrument data
• output: level-2 meteorological products generated from the input data
• logs: text files logging the progress of the algorithms as they generated the level-2 data

The input and output directories contain subdirectories for each product, and these each contain two files:

• A NetCDF4/HDF5 file with the suffix "h5" containing the retrieved data
• An XML file with the suffix "HDR" containing a description of the variables in the file (reproducing metadata already in the NetCDF4/HDF5 file)

Input products (L1)

The level-1 products are named Y-ZZZ where Y indicates the source of the data (A=ATLID, C=CPR, M=MSI, B=BBR and X=auxiliary) and ZZZ is a shortened version of the product name:

• A-NOM: Nominal ATLID measurements
• C-NOM: Nominal CPR measurements
• M-RGR: Regridded MSI measurements
• B-NOM: Nominal BBR measurements averaged to various scales
• B-SNG: Single-pixel BBR measurements
• X-JSG: Definition of the Joint Standard Grid on to which several of the observations are interpolated
• X-MET: Meteorological data from ECMWF

Single-instrument output products (L2a)

The naming convention is the same as the L1 data products.

• A-AER: ATLID aerosol profiles
• A-ALD: ATLID aerosol layer descriptor
• A-CTH: ATLID cloud top height
• A-EBD: ATLID extinction, backscatter and depolarization
• A-FM: ATLID feature mask
• A-ICE: ATLID ice cloud properties
• A-TC: ATLID target classification
• C-CD: CPR corrected Doppler velocity
• C-CLD: CPR cloud properties
• C-FMR: CPR feature mask and reflectivity
• C-TC: CPR target classification
• M-AOT: MSI aerosol optical thickness
• M-CM: MSI cloud mask
• M-COP: MSI cloud optical and physical properties

Multi-instrument output products (L2b)

The level-2b output products are named YY-ZZZ where YY is 2-4 character code conveying which of the four instruments were used and ZZZ is the shortened version of the product name.

• AC-TC: ATLID-CPR target classification
• AM-ACD: ATLID-MSI aerosol column descriptor
• AM-CTH: ATLID-MSI cloud top height
• BM-RAD: BBR-MSI broadband radiances (unfiltered)
• ACM-3D: ATLID-CPR-MSI constructed 3D scene
• ACM-CAP: ATLID-CPR-MSI synergistic retrieval of cloud, aerosol and precipitation
• ACM-COM: ATLID-CPR-MSI composite of single-instrument cloud and aerosol retrievals
• ACM-RT: ATLID-CPR-MSI radiative fluxes and heating rates computed on the retrievals
• BMA-FLX: BBR-MSI-ATLID broadband fluxes
• ACMB-DF: ATLID-CPR-MSI-BBR difference between radiances and fluxes computed from retrievals (ACM-RT) and measurements (BM-RAD, BMA-FLX)

Filename format

The data filenames and directories have the following name format:

ECA_EXAA_YYY_ZZZ_LL_OBSERVATION-TIME_GENERATION-TIME_VVVVVV

where:

• "ECA" indicates EarthCARE.
• EXAA indicates the file class: ESA, Latency N/A, Simulator, Baseline N/A.
• YYY is a three-character code indicating the instrumental source of the data. The 1-4 character codes defined in the sections above are converted to 3 character codes as follows: A -> ATL, C -> CPR, M -> MSI, B -> BBR, X -> AUX, AM -> AM_, AC -> AC_, BM -> BM_, ACMB -> ALL.
• ZZZ is a three-character code abbreviating the full name of the product, as defined in the sections above.
• LL represents the level of the data from 1B, 1C, 1D, 2A and 2B.
• OBSERVATION-TIME is a code representing the date and time the observations were taken in the form yyyymmddThhmmssZ. Note that for the present datasets the dates are fictional future dates.
• GENERATION-TIME is a code of the same form representing the time that the processor was run to produce the data product.
• VVVVVV indicates the orbit number and frame letter.

Further information may be obtained from the papers in the special issue of AMT. The description here may be expanded in future.

Contacts: Gerd-Jan van Zadelhoff <gerd-jan.van.zadelhoff@knmi.nl> and Robin Hogan <r.j.hogan@ecmwf.int>