This page will describe briefly the steps used to produce these renderings as well as give some information about the data itself.

• The Digital Elevation Data: The Digital Elevation Models (DEM) used in these renderings are a mosaic of 84 different 1:24,000 United States Geological Survey (USGS) DEMs. The data is in Universal Transverse Mercator (UTM) projection and cross two zones. The spatial resolution of the data is thirty meters per pixel. The vertical resolution is one meter, except for eleven quadrants in the Hawai'i Volcanoes National Park which was at one foot vertical resolution. These eleven quadrants were degraded to one meter vertical resolution to match the other quadrants. The two extreem west quadrants were resampled to match the same UTM zone as the rest of the quadrants. The data was supplied by the EROS Data Center in Sioux Falls, South Dakota, a branch of the USGS, Department of the Interior.

• The satellite imagery: The terrain map used for these Vistapro renderings are a mosaic created from 14 seperate SPOT images acquired in 1987, 1989, 1991, and 1994. The DEM mosaic was used as the map base and resampled to 20 meter resolution so that the SPOT imagery would not be degraded. The ocean was "blacked out" from the mosaic to allow for a seamless match. To be used as a texture map within Vistapro, the SPOT mosaic was converted to a PCX file and reduced to the four different Vistapro sizes, small, large, huge, and mega. The renderings on these pages were produced with the mega file. SPOT imagery is only available in a 10-meter panchromatic band and three 20-meter visible and near-infrared bands. The 20-meter bands produce a "false color composite" that is very common to most users of satellite imagery. The data was manipulated to produce the pseudo natural color image used in these renderings. This procedure is described on the "CIR2NAT" web page located on this server.

• The Vistapro procedure: Vistapro by default uses a color coded texture map based on the elevations within the data set. A texture map (satellite image) can be used instead of the default colors. The first step is to set the camera and target positions to the desired viewpoints. Set the quality rendering desired and output image size. Turn off all color manupulation switches except for Gouraud shading. Finally, load the cooresponding PCX texture map using the Import/PCX as Ground Colors. Follow the prompts and finally produce your rendering. Note: it is very easy to change the color palettes within Vistapro, so it may be required to relaod the PCX file after any changes you might make.