ESDU AERO 00.03.05 gives expressions for the variation with the ratio of pressure to stagnation pressure of the following ratios: the temperature to the stagnation temperature, the density to the stagnation density, the velocity to the speed of sound and the velocity to the speed of sound at stagnation conditions, and provides graphs of the functions. The ratio of specific heat capacities is taken as 1.4 and the air is assumed to behave as a perfect gas.