THE PROBLEM
Global warming and the greenhouse effect were once theories debated solely within the scientific community. The theories were just that -- only theories. Now, however, governments and the general public have grown increasingly aware of the effect of their human activities on the sensitive ecological balance of the planet, and, as a result, the theories are being taken seriously.

Scientists are concerned that the effects of deforestation, carbon dioxide emissions and the increase of the Earth's temperature by two or three degrees could cause major changes in weather and vegetation patterns as well as melting of the polar ice caps. The scientific community is attempting to gain a better understanding of the complex interactions of the global environment by studying data collected from various sources around the world.

Data-gathering efforts received a boost when the first European Remote Sensing Satellite (ERS-1) of the European Space Agency (ESA) was launched in 1991. Scientists worldwide have gained access to data about sea state, sea surface winds, ocean circulation and sea and ice levels as well as all-weather imaging of ocean, ice and land.

The magnitude and immense importance of the research demand that extensive on-ground testing of the satellite occurs before it is launched. Technical problems must be corrected to insure that the satellite's systems are fully operational because overlooked details could cripple the mission, resulting in lost time and resources. Enormous efforts are being undertaken to avoid this possibility.

THE SOLUTION
Scientists at the European Space Research Center (ESTEC) undertook one such effort. They developed a multipurpose data-analysis software package that is used in all phases of the project, from prelaunch testing through full commissioning. The package is capable of handling both the raw data generated by the satellite instruments and data processed at the ground station, called "fast delivery products."

The graphic display and interactive data analysis capabilities used in the Package are provided by PV-WAVE, Visual Numerics' visual data analysis (VDA) software product. Its surface representation and 2D functions are currently being used to create parameters to correct the satellite's position, analyze formats and debug the ground station software.

"The list of advantages to using PV-WAVE is too long to be detailed. It is flexible during data analysis, allows software transportability and is easy to learn and use. It is incredibly easy to debug my applications," said Van Petiteville of the ERS-1 project. "We get 100 percent satisfactory support from Visual Numerics' German subsidiary."

One of the ground station products PV-WAVE visually analyzes is a 63-megabyte Synthetic Aperture Radar (SAR) image compressed into a 0.5-megabyte "Imagette." Using a mouse and the Histogram Equalization function to select a portion of the original image, scientists can expand the dynamics of the picture and display it on any bit-mapped screen. This technique allows them to display a 500 x 500 km wind field scene in a meteorological representation and superimpose it over the SAR image.

PV-WAVE is used to visually study the incoming fast delivery products, to perform processing on calibration data and to correct various processing software, allowing for the biases determined from the product analysis.

RETURN ON INVESTMENT
System developers have created a software tool that will display various data types over a world map, allowing users to visualize their requests regarding the satellite's orbit number or its earthbound data gathering. A user-friendly interface enables the researcher to access such information as time, the satellite's orbit number or its latitude and longitude at any location on the planet. PV-WAVE's imaging and raster display functions help the developers save time implementing display routines and window management procedure.

"The best way to realize the power of PV-WAVE," Petiteville concluded, "is to use it in a real industrial context where you have to process a large amount of information and react to it quickly."

ESTEC scientists rely on PV-WAVE for all problems relating to image and graphic display, interactive data processing and user interface, and their productivity in software development has increased immeasurably.

WORLD CLASS PRODUCTS, SERVICES, AND SUPPORT
Visual Numerics has provided technical software solutions for numerical analysis and visualization for over 30 years. The company's software products help users understand complex data from a variety of sources and build business-critical applications. Visual Numerics offers two product lines: the IMSL® Numerical Libraries for powerful mathematical and statistical analysis and the PV-WAVE® visual data analysis development environment. Visual Numerics also offers customized consulting services for applications that involve mathematical, statistical, or visual data analysis to meet today’s business analytical needs.