ijk2keplerian

Keplerian orbit elements using position and velocity vectors

Description

example

[a,ecc,incl,RAAN,argp,nu,truelon,arglat,lonper] = ijk2keplerian(r_ijk, v_ijk) calculates Keplerian orbit elements for given position and velocity vectors in the geocentric equatorial coordinate system.

Examples

collapse all

Convert the geocentric equatorial coordinate system (IJK) position and velocity to Keplerian orbital elements.

r_ijk = [-2981784 5207055 3161595];
  v_ijk = [-3384 -4887 4843];
  [a, ecc, incl, RAAN, argp, nu, truelon, arglat, lonper] =...
   ijk2keplerian(r_ijk, v_ijk)
a =
   6.7845e+06

ecc =
   9.1950e-04

incl =
   51.7528

RAAN =
   95.2570

argp =
  106.4005

nu =
  290.0096

truelon =
   NaN

arglat =
   NaN

lonper =
   NaN

Input Arguments

collapse all

Geocentric equatorial position components, specified as a 3-by-1 array.

Data Types: double

Geocentric equatorial velocity components, specified as a 3-by-1 array.

Data Types: double

Output Arguments

collapse all

Semimajor axis (half of the longest diameter) of the orbit, returned as a scalar, in meters.

Data Types: double

Orbit eccentricity (deviation of orbital curve from circular), returned as a scalar.

Data Types: double

Inclination (tilt angle) of the orbit, in degrees.

Data Types: double

Angle in the equatorial plane from the x-axis to the location of the ascending node (point at which the satellite crosses the equator from south to north), in degrees.

Data Types: double

Angle between the CubeSat ascending node and periapsis (closest point of orbit to Earth), in degrees.

Data Types: double

Angle between periapsis and current position of CubeSat, in degrees.

Data Types: double

Angle between the x-axis and CubeSat position vector, in degrees.

Data Types: double

Angle between the ascending node and the CubeSat position vector, in degrees.

Data Types: double

Angle between the x-axis and the eccentricity vector, in degrees.

Data Types: double

References

[1] Vallado, D. A. Fundamentals of Astrodynamics and Applications. alg. 5. McGraw-Hill, 1997.

Introduced in R2019a