A New Tool for Estimating Atmospheric Conditions in Four Dimensions

摘要

The U.S. Standard Atmosphere was published under the sponsorship of ICAO, NASA, the United States Air Force, and the United States Weather Bureau. The original edition was published in 1962 with the latest update in 1976. The only differences between the 1962 and 1976 versions are above 52 km. The Standard Atmosphere is useful in establishing a uniform model with which to conduct aircraft design and performance calculations. Daily variations in the actual atmosphere is accounted for in well-established aviation procedures concerning altimeter settings, pressure altitude, density altitude, and 'indicated' vs. actual air speeds. All of these methods refer back to the Standard Atmosphere. When planning a stratospheric balloon mission in which altitude accuracy is of high importance, it is important to have a better understanding of the atmosphere that the mission is planned for. The United States Air Force published a supplemental atmospheric table in 1978 that gives the data needed to calculate the properties of the atmosphere throughout the year at various latitudes. This model is compared to actual sounding data from similar times of year and from similar latitudes. The sounding data compares quite favorably to the Air Force model. The impact of seasonal and latitudinal variations on balloon altitude performance is presented.