Joint Terrain Analysis Program (JTAP)

The Joint Terrain Analysis Program (JTAP) is used to create interactive radio frequency (RF) coverage plots for communications and radar equipment through the use of Digital Terrain and Elevation Data (DTED). The application allows users to create plot types, including line-of-site, pathloss, received signal power, and field intensity, which are overlaid on a Geographic Information System (GIS) background. The interactive coverage plot display features a cursor, which can be moved within the plot area, displaying signal data, elevation, and latitude and longitude for the cursor location. Transmitter icons can be dragged and dropped anywhere within the plot area. A zoom option provides enhanced details of user-selectable areas within the plot.

JTAP has a shape file export capability that is compatible with Arc/View. The shape file format supports additional JTAP point, line, and area features, such as transmitter locations. Available plot types include line-of-sight, pathloss, received signal power, and field intensity.

Using a Longly-Rice propagation model, JTAP’s sophisticated propagation engine

operates over the frequency range of 1 MHz to 20 GHz and performs pathloss and line-of-sight calculations based on antenna heights, intervening terrain, environmental characteristics, and equipment characteristics. Air, ground, or sea platforms may be evaluated.

The JTAP application includes fixed and mobile transmitter options. The user specifies the transmitter characteristics and locations, receiver characteristics, map features, and environmental data. Coverage plots may be displayed singly or may be overlaid to show signal coverage from multiple transmitter sites. The various types of plots may be displayed in separate windows for comparison. JTAP can use two-dimensional antenna radiation patterns to calculate and display effective received power and effective field intensity. Antenna patterns may be supplied by the user or may be generated by the JTAP Gaussian antenna model.

In addition to creating and displaying coverage plots, JTAP provides a database of Department of Defense (DoD) transmitter and receiver equipment characteristics that the user may select from while creating a coverage plot. The user may add, delete, or edit any of the information contained in the master database.