Accession Number : ADA119496

Title :   A Method to Correlate the Upper Air Density with Surface Density and Estimate the Ballistic Density for Air or Surface Launched Missiles.

Descriptive Note : Final rept.,

Corporate Author : NAVAL SURFACE WEAPONS CENTER DAHLGREN VA

Personal Author(s) : McAnelly,Loren J

PDF Url : ADA119496

Report Date : Jul 1982

Pagination or Media Count : 118

Abstract : Atmospheric data collected twice daily from five ocean stations over a period of 7 years were used in a study to correlate ballistic densities at various levels. The study indicates that a good correlation does exist and that tables, nomograms, or data in a suitable format should be produced for use with new and existing fire control computers and range tables prepared for the Fleet. Two exponential functions of altitude were used to express the density-one from surface to 36,000 ft, the other from 36,000 to 65,000 ft. The coefficients were selected in a manner that produces a continuous function from sea level to 65,000 ft. The coefficients of the two functions were determined using a nonlinear least-squares technique. Fluctuations in the density profiles below 5,000 ft altitude were noted and were investigated by fitting a sample of temperature and pressure data with a least-square technique. Ballistic densities for firing at surface targets were computed for altitudes to 50,000 ft. While the current projectiles in the Fleet may not reach an altitude of 50,000 ft., this may become a reality in the near future. The procedure presented in this report could very easily be modified to compute ballistic density when firing at air targets at altitudes up to 50,000 ft. (Author)

Descriptors :   *Atmospheric density, *Nomographs, *Ballistics, *Correlators, *Least squares method, Surfaces, Density, Firing tables, Fire control computers, Surface launched, Air launched, Guided missiles, Aerial targets, Upper atmosphere

Subject Categories : Atmospheric Physics
      Statistics and Probability
      Fire Control and Bombing Systems

Distribution Statement : APPROVED FOR PUBLIC RELEASE