Tracking Rocket Nominal Launch and Abort Plumes Using WSR-88D Doppler Radar

Range safety personnel continually assess the accuracy and reliability of dispersion models used to predict concentrations downwind of nominal launch and potential rocket abort plumes. One tool which has been successfully used to monitor the track of these plumes from rocket launches at Cape Canaveral Air Force Station (CCAFS) and Kennedy Space Center (KSC) has been the WSR-88D Doppler radar located at the National Weather Service office in Melbourne, Florida. The radar is sensitive enough to detect the small particles and droplets that are produced by burning solid and/or liquid propellant. A radar display unit located in the Range Operations Control Center shows color-coded products which are updated every 5-10 minutes. The radar display operator can determine the location, height, and intensity of a launch or abort plume using the display's user interface. These data are being used to assess the predicted plume track from the Rocket Exhaust Effluent Dispersion Model (REEDM). Radar data have been collected from nominal launches of the Space Shuttle, Titan IV, Delta II, Delta III, Atlas and other vehicles for up to 45 minutes after launch. Extensive data were collected following the Delta II explosion on 17 January 1997 when the abort plume was tracked for over 4 hours by the Melbourne radar. This paper presents the results of the radar data collection effort for Cape Canaveral launches since January 1997. The radar data are compared with the REEDM results to evaluate model accuracy in predicting plume track.