Expand description
Normal gravity of a level ellipsoid (WGS 84 by default), and the gravity models the flight engine chooses from.
Normal gravity is the gravitational attraction of the reference ellipsoid plus the centrifugal
acceleration of the Earth’s rotation, so it is the acceleration a body at rest relative to the
Earth feels. A simulation in an Earth-fixed frame adds only the Coriolis term
(crate::earth); adding a centrifugal term as well would count it twice.
Source: NGA.STND.0036_1.0.0_WGS84, Department of Defense World Geodetic System 1984
(2014-07-08), chapter 4 and appendix B. Details and tests are in docs/physics/gravity.md.
Structs§
- Normal
Gravity - The normal gravity field of a level ellipsoid, fixed by four defining parameters:
a,1/f,GMandω. Everything else is derived from them (NGA.STND.0036 appendix B).
Constants§
- STANDARD_
GRAVITY_ MPS2 - Standard acceleration of free fall,
g₀ = 9.80665 m/s²: the conventional value adopted by the 3rd CGPM (1901) and used by the U.S. Standard Atmosphere, 1976. It is not the gravity at any particular place. - WGS84_
ANGULAR_ VELOCITY_ RAD_ S - WGS 84 nominal mean angular velocity of the Earth
ω, rad/s (NGA.STND.0036, Table 3.1). - WGS84_
GM_ M3_ S2 - WGS 84 geocentric gravitational constant
GM, m³/s² (NGA.STND.0036, Table 3.1).