Jet Standard Atmosphere - no such animal. I'd like to see your providence.
The SR-71 Flight Manual uses the ARDC Model Atmosphere (1956)
A hypothetical vertical distribution of atmospheric temperature, pressure, and density which, by international agreement, is taken to be representative of the atmosphere for purposes of pressure altimeter calibrations, aircraft performance calculations, aircraft and rocket design, ballistic tables, etc. The air is assumed to be devoid of dust, moisture, and water vapor and to obey the perfect gas law and the hydrostatic equation (the air is static with respect to the earth). Standard atmospheres which have been used are:
(a) The NACA standard atmosphere, also called U.S. standard atmosphere, prepared in 1925, which was supplanted by
(b) The ICAO standard atmosphere, adopted in 1952, which was extended to greater altitudes by
(c) The ARDC model atmosphere, 1956, and
(d) The U.S. extension to the ICAO standard atmosphere, adopted in 1956, which has been revised by
(e) The ARDC model atmosphere, 1959, which incorporated some satellite data which has been supplanted by
(f) The U.S. Standard Atmosphere-1962. Standard updated in 1966 and 1976. The U.S. Standard Atmosphere is the same as the ICAO Standard Atmosphere for altitudes up to 32km. ICAO Standard currently extends to 80km.