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1.3. About this manual

This manual was developed to provide an introduction to WinDisp Version 3.5 to new users, while also providing some in-depth background and reference materials for advanced users of the program. This manual builds upon the previous reference materials distributed with the software by Eric Pfirman, and the IDA for DOS Version 4.2 User Manual developed for FAO ARTEMIS by Peter Hoefsloot.

Chapter 2 provides detailed descriptions of the WinDisp interface, how to display maps and images, how to develop project files and batch routines, and how to use the image analysis functions. Chapter 3 provides the same information contained in the on-line help available in WinDisp which was produced by Eric Pfirman. Chapter 4 provides a detailed description of the primary file types used by WinDisp.

The data and examples used in Chapter 2 are for Africa and focus on the use of satellite imagery in early warning for food security. Satellite images are often the only information available in near real-time for the arid and semi-arid regions of Africa, which are often subject to drought and poor crop conditions, and where timely and reliable ground information is often difficult to obtain. Two types of satellite data have proven useful for early warning: normalised difference vegetation index (NDVI) images, and cold cloud duration (CCD) images. These images can be used to compare the current growing season with a historical archive of NDVI images dating back to mid-1981, and CCD images dating back to 1988. The NDVI images have a pixel-size of roughly 7.6 x 7.6 km, often called Global Area Coverage or GAC resolution, and the CCD pixel-size is 5 x 5 km corresponding to the native pixel size of the METEOSAT series satellites.

The maps and tabular data used in the examples are from the GIEWS Workstation database which were collected from various sources. The NDVI imagery was produced at the Laboratory for Terrestrial Physics at the NASA Goddard Space Flight Center and are derived from the AVHRR sensor aboard the NOAA series of meteorological satellites. The CCD imagery used in the examples were produced by the FAO ARTEMIS system and compiled from data received from the METEOSAT series of satellites.


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This manual was prepared by the Global Information and Early Warning System of the United Nations Food and Agriculture Organization
© FAO/GIEWS - 1999
E-mail: Giews1@fao.org