The East Central Florida region was selected as the (TRMM) LIS validation domain. The primary reason for this selection was the presence of LDAR at KSC. The LIS validation domain encompasses a region falling within a 150 km range centered around the Me lbourne (MLB) NEXRAD site. The actual bounds of this region are 26.7641 N, -79.1245 E to 29.4621 N, -82.1833 E. The TRMM satellite overpasses for this region are generally around 2 minutes or less. The overpass time period is used to extract and plot data from ground-based instruments. The different data sets used for ground truth validation are: LDAR NLDN WSI Radar Ground Truth Calendar Information The calendar page for each month contains the overpass times that the LIS instrument traversed the validation domain for each day of the month. The times are colored in blue. Additionally, the page also contains the total number of flashes that are obs erved by LIS during each overpass. Overpass Display Information From the calendar, a user can select the ground truth display page for a particular overpass time. This page contains four plots, showing data from LIS as well as from three ground truth instruments. The LIS overpass image provides the exact times fo r the instrument crossing over the validation region. Group density measured by the LIS instrument is depicted on the plot as a measure of lightning activity. The swath area is colored in a shade of green to distinguish it from the background. Both lightning flashes and source data are shown in the LDAR plot for each overpass time. The sources are plotted on two different planes to depict spatial distribution along the vertical. Unlike LIS or LDAR, which measure total lightning, NLDN measures only the cloud to ground lightning. The NLDN display has cloud-to-ground strikes demarcated into positive cloud to ground flashes and negative cloud to ground flashes. The WSI radar image is a composite radar reflectivity image created using the current operational National Weather Service radars. The national composite image is subsetted for the LIS validation region. Since the GHRC receives a national composite ima ge every 15 minutes, the national composite image nearest to the overpass time is selected for subsetting.

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