CL_gm_lat2locTime

Description

• This function is deprecated.

  Replacement function: CL_gm_orbSphTriangle

• Computes the satellite's local time at a given latitude.

  The satellite local time is computed from the local time of the ascending node (loctime_asc_node), the orbit's inclination (inc) and the satellite's latitude (lat).

  Two solutions exist, that correspond to the satellite latitude increasing (loctime_asc) or decreasing (loctime_desc).

• Notes:

  - A spherical planet is assumed.

  - The model used is Keplerian and the Sun direction is constant relative to the orbit plane.

  - The latitude in absolute value must be less than max(inclination, pi-inclination).

  - A satellite local time equal to 12h means than the satellite's right ascension is equal to the Sun's right ascension.

  - "Local time" here means "true local time".

Parameters

lat:

Satellite latitude [rad] (1xN)

inc:

Inclination [rad] (1xN)

loctime_asc_node:

Local time of ascending node [hours] (1xN)

loctime_asc:

Satellite local time (ascending path) [hours] (1xN)

loctime_desc:

Satellite local time (descending path) [hours] (1xN)

Authors

• CNES - DCT/SB

Bibliography

• 1) Satellites orbites et missions - Michel Capderou

Examples

inc = CL_deg2rad(98.6); lat = CL_deg2rad(-90+9:1:90-9); loctime_asc_node = 22; [lt_asc,lt_desc] = CL_gm_lat2locTime(lat,inc,loctime_asc_node);