An old formula of some interest
The "ram rise" or increase in temperature of the air when it goes from free-stream velocity, i.e., True Air Speed to stagnation point may be found by taking the uncorrected Outside Air Temperature (OAT) and computing a "rough" value for TAS, then squaring that value and dividing by the constant 9500.
This will give you the temperature ram rise in degrees C.
This rise may then be subtracted from the uncorrected OAT to obtain actual air temperature, i.e., SAT.
The SAT value thus found can be used to re-calculate TAS and obtain an accurate value for same.
This is the way it used to be done when all we had was an uncorrected temperature probe and a hand-held mechanical computer.
Mathematically:
Ram Rise in Deg. C = TAS sqrd / 9500
Uncorrected OAT - Ram Rise = SAT