kConstantSpeedOfLight is "c" the constant speed of light [m/s].kConstantSLP Sea-level Pressure [hPa].
kConstantP0 Reference pressure [hPa].
kConstantRe Earth's radius [m].
kConstantR43 4/3 Approximation effective radius for standard atmosphere [m].
kConstantBoltz Boltzmann's constant [ m^2 kg s^-2 K^-1].