In this report we investigate communications problems faced by emergency responders (firefighters and police) in disaster situations (i.e., collapsed buildings). A fundamental challenge to communications into large building structures is the strong attenuation of radio signals caused by losses and scattering in the building materials and structure. We designed experiments that take advantage of building demolitions in an effort to quantify radio signal attenuation through standing and collapsed structures. We also investigated various schemes for detecting signals from firefighters and civilians with portable radios or cell phones who are trapped in voids in these collapsed building. We placed RF transmitters similar to those used by first responders in various locations in these buildings and performed various measurements before, during, and after the building was imploded. The transmitters are tuned to frequencies near public safety and cell phone bands. Once the building is down, we used the signals from the buried transmitters in the building to investigate various detection schemes which involved searching with directional antennas and connecting instruments to some of the metal debris located on the perimeter of the collapsed building. This report summarizes one such set of experiments in a 13 story apartment complex in a suburb of New Orleans, Louisiana. In this report, we describe the experiments, detail the measurement system, show primary results of the data we collected, and discuss some of the interesting propagation effects observed.
Technical Note (NIST TN) - 1540
building implosion, communication, first responders, radio propagation measurments