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1. Introduction

This manual was developed to accompany the multilingual version of the PC-based map and image display and analysis software WinDisp Version 3.5. WinDisp is a public domain, easy to use software package for the display and analysis of satellite images, maps and associated databases, with an emphasis on early warning for food security. WinDisp was originally developed for the FAO Global Information and Early Warning System with funding from the European Commission. The system, following several enhancements, has become the Windows-based successor to the DOS based Image Display and Analysis (IDA) software system which was also developed in support of early warning analysis.

1.1. General description of WinDisp3.5

WinDisp Version 3.5 is multilingual with all menus, on-line help, and reference documents available in English and French. A Spanish version is under development at the time of writing. WinDisp offers varying degrees of automation and ease of use. The software allows users to compare multiple images; extract and graph trends from a number of satellite images, such as during the growing season for comparison with other years; compute new images from a series of images; build custom products combining images, maps and specialised legends; and to display tabular data in map format. WinDisp supports project files which can be developed for specific countries and regions. These allow users to point and click from various data themes to build composite maps and to do some basic early warning analysis in a series of display windows. WinDisp has extensive batch processing capabilities which can be utilised to automate routine and tedious tasks, and permits users to develop custom applications and procedures.

WinDisp was developed by Eric Pfirman, Justin Hogue and Linda See, the first two having also developed IDA. The satellite enhanced data interpolation (SEDI) routines included in WinDisp3.5 were developed by Peter Hoefsloot. This documentation was prepared by Eric Pfirman and Isabelle Charlier, with translations by Isabelle Charlier, Linda See and John Lewis.

1.2. History of WinDisp

WinDisp has its origins with the Global Information and Early Warning System (GIEWS) of the Food and Agriculture Organization of the United Nations. The GIEWS monitors the global food supply and demand and provides timely warnings about both food shortages and surpluses for individual countries. The GIEWS required an integrated information system to keep up with the ever-increasing flow of data as well as to enable GIEWS staff to distil large inputs of a variety of data into useable and manageable information. In response to this need the GIEWS, with funding and support from the European Commission, developed an integrated information system now known as the "GIEWS Workstation".

WinDisp was developed as the map and image display module of the GIEWS Workstation, permitting GIEWS analysts to analyse, integrate, and overlay digital map and satellite data in common windows on their desktop PCs. It was designed to make the display and analysis of satellite images, maps and associated databases as simple as possible. The image and map file formats used by WinDisp are identical to its DOS based predecessor IDA (see below) which was already widely in use for image analysis within the early warning community at the time WinDisp development began.

WinDisp is often termed the successor to the Image Display and Analysis (IDA) software. While both were contemporaneous for a period, IDA was developed much earlier in the mid-1980s by the USAID Famine Early Warning System (FEWS) Project as a PC based image analysis tool, and was made freely available to anyone who requested it. IDA was initially developed by Eric Pfirman and Richard Collins, with later versions by Eric Pfirman and Justin Hogue. The software was used extensively within the early warning community for the analysis of low resolution, high frequency satellite imagery in near real-time. IDA allowed for the use of satellite images at field level as it operated on most PC platforms available at the time. In the early 1990s, the USAID FEWS Project, the United States Geological Survey EROS Data Center, and the ARTEMIS system at the FAO Remote Sensing Centre in Rome helped fund upgrades of the software, including support for other languages and a detailed user manual.

WinDisp has evolved from an MS-Windows based image display tool for viewing IDA images in Version 1.0, to a fully functional, multilingual, image analysis and map display software tool for early warning in its current version. This evolution was gradual with WinDisp first being customised and upgraded to meet the needs of the GIEWS, which resulted in WinDisp2.0. Version 2.0 offered an easy to use, high-level data browsing tool for decision-making support, and provided the user with multiple-window capabilities, support for displaying a wider variety of file formats, and the ability to map tabular data. A "project" interface was added in Version 2.0 which could be customised to provide the user with a list of the available data for a country or specific area, and permitted the creation of detailed menus for selecting, displaying and integrating various tabular data, digital maps and satellite images.

By the time WinDisp2.0 was finalised and in use by the GIEWS, the IDA user community was looking for an MS-Windows based version of IDA. Though the FAO GIEWS had funded an initial version of IDA for Windows, that software did not take advantage of the full functionality that could be offered under MS-Windows. Since the same team of programmers, led by Eric Pfirman at the University of Arizona, had developed IDA for DOS, IDA for Windows, and WinDisp, it was proposed that WinDisp be enhanced to incorporate all of the analytical features of the IDA for DOS program.

This proposal was agreed upon by many IDA users, and funding was obtained from the US Agency for International Development's Famine Early Warning System (FEWS) Project, the Southern African Development Community (SADC) Regional Remote Sensing Project (RRSP), the USDA Forest Service (USFS) Intermountain Fire Sciences Laboratory, and the US Geological Survey (USGS) EROS Data Center. The new product, entitled WinDisp3.0, offered all the features and ease of use of the previous WinDisp2.0, full IDA functionality, several new display and data exploration features, and a powerful batch language giving Version 3.0 production capabilities. The contribution to the further development of WinDisp by these agencies proved beneficial to all involved. The software was enhanced to meet analytical needs of several agencies and early warning systems saving them from having to develop similar software at much higher cost. In addition, to further improving the analytical capabilities of the system, the adoption of WinDisp3.0 for map and image analysis by the early warning community has allowed the exchange of information between the users to be transparent.

Following the release of WinDisp3.0, FAO further enhanced the capabilities of WinDisp which resulting in the current Version 3.5. The European Commission was the primary source of funds for the further development of the GIEWS Workstation and WinDisp3.5. In addition, the FAO Africa Real Time Environmental Monitoring Information System (ARTEMIS) and a Ministère de la Coopération Française funded activity at the GIEWS helped fund additional enhancements to Version 3.5.

Version 3.5 offers new communications parameters which enable WinDisp to receive automated commands from other software systems, new mapping and legend feature, and the satellite enhanced data interpolation (SEDI) routines derived from the IDA GIS Tools software developed for the Southern African Development Community (SADC). In addition, WinDisp3.5 was modified to support multilingual versions of the menus and on-line help files as part of the effort to distribute the Workstation to other early warning units in non-English speaking countries. A multi-lingual dictionary currently allows the user to choose between English and French versions of the software. The dictionary can also be adapted for other languages. All WinDisp menus, the on-line help, and reference documents are now available in English and French with Spanish under development.

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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