From captures at archive.org, the website redirected to the new page for a while, before it went completely offline.
New page: https://ghrc.nsstc.nasa.gov/lightning/
Comparing it to archived versions, it seems that it has roughly the same content as the original Lightning Research - GHRC site, although the file paths don't seem to be the same, breaking old links.
At the bottom of the lightning primer page there is a link for Detection Instruments where a different copy of that image still exists.
Lightning Detection and Ranging (LDAR)
Located at the Kennedy Space Center, the LDAR consists of seven antennas that detect electromagnetic pulses at 66 MHz, which allows it to detect 99% of all flashes (both intracloud and cloud-to-ground flashes) within 10 km of the antenna network. The accuracy of source locations is a function of position relative to the receiving array, generally decreasing (particularly along the radial axis with respect to the array center) with distance. The RMS error for LDAR lightning source locations varies from 100 meters inside the network to about 10 km at a range of 90 km (about 1/3 the width of the Florida peninsula).