The improvements and updates with respect to Collection 1 are the following:
- Cloud detection algorithm
A Multi-Layer Perceptron (MLP)-based neural network algorithm is applied, with no auxiliary data dependency, resulting in significant improvements compared to the Collection 1 cloud detection.
- Radiometric Instrument Calibration Parameter (ICP) files
The absolute calibration and equalization coefficients are updated, as well as some inter-band corrections to the BLUE and SWIR channels are performed.
- Atmospheric correction
The Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2) Aerosol Optical Thickness (AOT) dataset is used as input for the atmospheric correction. The resulting TOC reflectances are validated following the ACIX validation method.
- Product data format
The current Collection 1 data are available as HDF5 and GeoTIFF files. For Collection 2, the new Cloud Optimized GeoTIFF standard, backward compatible with standard GeoTIFF, will be used in addition to the regular HDF5 file format. Using this new and state-of-the-art data format standard eases the file handling and data visualization in cloud environments.
- New product search catalogue
PROBA-V Collection 2 data will become more easily searchable using the OpenSearch CAtalogue for Remote Sensing (OSCARS) from a new, dedicated, and improved user interface, combining the best from PROBA-V’s Mission Exploitation Platform (such as time series and viewing) to give you a seamless user experience and to efficiently analyze the Collection 2 data.
- CEOS Analysis Ready Data (CEOS-ARD) compliancy
PROBA-V Collection 2 surface reflectance data will be CEOS-ARD-compliant, which means that it will fulfil a set of accuracy thresholds, that essential corrections are applied, and that the product metadata are structured in a certain format. This will enable you to start analyzing Collection 2 data immediately, without the hassle of complex additional pre-processing.
The above listed changes impact all Level-2A and Level-3 data at all resolutions (100 m, 300 m, and 1 km). Collection 2, together with its user documentation, becomes available end of March 2023. Meanwhile PROBA-V Collection 1 data remain available for 2 months after publication of the Collection 2 products.