Ground Cloud Dispersion Measurements During the Titan IV A-17 Mission (7 November 1997) at Cape Canaveral Air Station.
Abstract
This report presents plume imagery documenting the development and dispersion of the Titan IV A-17 launch ground cloud at Cape Canaveral Air Station on November 1997 at 2105 EST. Also presented are pertinent meteorological data taken from towers, Doppler radars, and rawinsonde balloons, IR cameras were used at four locations around the launch site to track the trajectory and time evolution of the exhaust ground cloud for 7.5 min following launch. Meteorological data were collected to improve understanding of cloud dispersion and to use as input during model simulations and evaluations. Rawinsonde balloon data, 915 MHz Doppler radar data, and meteorological tower data were collected and archived. These data and similar data from other launches will be used to determine the accuracy of atmospheric dispersion models such as the Rocket Exhaust Effluent Diffusion Model (REEDM) in predicting toxic hazard corridors (THCs) at the USAF Eastern and Western Ranges. Analysis of imagery data from the first 9.5 min following launch yielded information on cloud rise and dispersion. The imagery showed that the middle of the launch cloud stabilized at an altitude of 1192 m AGL by 4.25 min after launch. REEDM 7.08 predicted that the middle of the launch cloud would stabilize at 947 m AGL at 4.65 min after launch. The middle of the actual launch cloud therefore stabilized 26% higher than predicted by REEDM 7.08. Analysis of the imagery also showed that the rising cloud had an air entrainment coefficient (ratio of increase in diameter to increase in altitude) of 0.33 (REEDM 7.08 default value is 0.64). The initial cloud radius extrapolated from the imagery was 168 m. (REEDM 7.08 default value is 72 m). REEDM 7.08 predictions for bearing, speed, and stabilization height were closer to the observed values when REEDM was initialized with the imagery-derived for the initial radius and the entrainment coefficient rather than with the default values.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 20, 1999
- Accession Number
- ADA363999
Entities
Organizations
- The Aerospace Corporation