VGTExtract -- version 2.1.0
VGTExtract tool is a simple, user-friendly and free utility that aims to simplify and automate the integration of basic and derived SPOT-VEGETATION products in a variety of GIS and Remote Sensing software for further analysis, processing or visualization.
Purpose and limitations
A variety of basic and derived SPOT-VEGETATION products are produced by VITO and its partners and distributed through various channels such as web and FTP sites, the EUMETCast satellite broadcast and on fixed media. The distributed products are usually in the form of zipped archives that consist of one or more data files in HDF (4 or 5) or GeoTiff file format, a text or XML file containing the product's metadata, a copyright document and a sub-sampled Tiff image for quick content checking (so-called quicklook image). They can cover the entire world, entire continents, individual countries, regions or 10°x10° tiles. As the provided format and geographic coverage are not always what the user requires, the VGTExtract tool helps to fill the gap between what is delivered, and what the EO-experts need.
VGTExtract searches for VGT products in a given directory and its subdirectories. For each product found, VGTExtract can automatically unpack (uncompress) the product and perform the following actions on the resulting data files:
In addition, VGTExtract checks if the desired output region intersects with the coverage of the input product and fill the output image with missing data value where needed. It also uses the input product's metadata to check if the conversion would cause a loss of information and the quicklook image for providing a preview of the products used.
- Recognize, group and mosaic the data layers when they are provided as a set of regular tiles, such as the 10°x10° tiles produced in the frame of GMES Land's BioPar service
- Extract a given rectangular bounding box or Region of Interest (ROI)
- Convert to the following set of commonly used formats:
- Raw binary
- Change data type as may be required by the output format
- Apply a linear encoding with scale and offset to all values except one (and only one) special value for missing data.
This tool can be executed both in interactive mode and in batch mode (command line, for automation).
The utility is intended for all users capable of receiving VEGETATION products via EUMETcast, or with issues on importing and converting the format of VEGETATION data. As it facilitates the integration into other GIS and Remote Sensing (RS) software, it is recommended that users have at least a basic understanding of GIS or RS.
VGTExtract requires a Java virtual machine (JVM) to run. Users are advised to
download the version of VGTExtract with JVM. That installer will allow
you to install a JVM or to use a JVM that is already installed on your computer.
The VGTExtract version without Java virtual machine, which requires an already
installed JVM to run, is only provided here for users with limited download capacity.
The previous major version, 2.0, introduced the support for VEGETATION-derived products in HDF5 and GeoTiff format, like those produced in the frame of the GMES Land service, particularly the component for production of biophysical parameters at global scale. Furthermore, it extended the support for the basic raw VEGETATION products, called P segments.
The current version, 2.1, adds a work-around solution for the sticking of 10x10 degree tiles in HDF5 en GeoTiff formats, as provided through GMES Land. Moreover, the output in GeoTiff format has been significantly enhanced, through a series of tests in around 10 different GIS and remote sensing software.
Please consult the user guide, notably sections 3.1 and 3.2, for more information.
The VGTExtract tool was originally created by VITO in the frame of the FP6-VGT4Africa project, but has since been maintained and extended in the frame of the FP7-DevCoCast, FP7-Geoland2 and FP7-AGRICAB projects.