Synoptic and Climatological Density Profiles from Constant Pressure Surfaces for Ballistic Computations.
Abstract
The influence of atmospheric density on ballistic trajectories of re-entry vehicles usually attains a maximum below 20 kilometers. The most direct and accurate means of estimating this influence is from profiles of density specified at uniform intervals of altitude (usually 2 km) from individual soundings for the time and over the area of re-entry. Unfortunately, vertical distances between levels on constant pressure charts, normally available for obtaining density profiles, are generally greater than 2 kilometers. Unless interpolation between these pressure surfaces for obtaining densities at the 2-km intervals is based on the actual density-altitude relation, the interpolated densities will be in error. Three often-used methods of interpolation are: (1) assumption of a linear decrease of density with altitude, (2) assumption of a linear decrease of the logarithm of density with altitude, and (3) assumption of a linear decrease of density multipliers with altitude, where a density multiplier at the altitude of a constant pressure surface represents the ratio of density to the Standard Atmosphere density at that altitude. The three methods with resultant errors are discussed and evaluated in this report. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 04, 1971
- Accession Number
- AD0726994
Entities
People
- Allen E. Cole
- Arthur J. Kantor
- Henry A. Salmela
- Norman Sissenwine
Organizations
- Air Force Cambridge Research Laboratories