Examples
sma = 10000.e3; inc = 0.5; // rad dlon = CL_op_equatorialSwath("cen2dlon", sma, inc, 0.3) cen = CL_op_equatorialSwath("dlon2cen", sma, inc, dlon) |  |  |
Intersection of swath with equator (circular orbit and field of view)
ang2 = CL_op_equatorialSwath(cmd,sma,inc,ang1 [,er,mu,j2,rotr_pla]) longitude_span = CL_op_equatorialSwath("cen2dlon",sma,inc,center_angle [,er,mu,j2,rotr_pla]) center_angle = CL_op_equatorialSwath("dlon2cen",sma,inc,longitude_span [,er,mu,j2,rotr_pla])
Computes the (half) length of the portion of the equator seen by the satellite as the satellite crosses the equator.
There are 2 possibilities.
- The field of view (defined by a center angle) is known: the span in longitude is then computed (cmd should be "cen2dlon").
- The span in longitude is known: the field of view (defined by a center angle) is then computed (cmd should be "dlon2cen").
Notes:
- The planet is assumed spherical, and the orbit circular.
- The effects of J2 and Earth rotation are taken into account.
- The input center angle and span in longitude should be in [0,pi] and [0, 2*pi] respectively.
Warning:
There are two temporary limitations:
- Center angle must be less than pi/2.
- Semi major axis and inclination must be such that there is less than one revolution of the satellite per (orbital) day.
Otherwise, the value %nan is returned.
(string) Action required: "cen2dlon" or "dlon2cen"
Semi major axis [m] (1xN or 1x1)
Inclination [rad] (1xN or 1x1)
Input angle: center angle or half longitude span [rad] (1xN or 1x1)
(optional) Equatorial radius [m] (default is %CL_eqRad)
(optional) Gravitational constant [m^3/s^2] (default value is %CL_mu)
(optional) Second zonal harmonic (default is %CL_j1jn(2))
(optional) Rotation rate of the planet (default is %CL_rotrBody)
Output angle (half longitude span or center angle) [rad] (1xN)
CNES - DCT/SB
sma = 10000.e3; inc = 0.5; // rad dlon = CL_op_equatorialSwath("cen2dlon", sma, inc, 0.3) cen = CL_op_equatorialSwath("dlon2cen", sma, inc, dlon) | | |