This file describes coordinates used in the data sets of the multi-spacecraft
data collection from TASPD SINP MSU.
Geocentric spacecraft are supplied with the coordinates - geographic and
geomagnetic - listed below. The data from the high-altitude satellite
GRANAT for the periods of its large geocentric distance are supplied with
geographic coordinates only.
Geographic coordinates:
H,km - current height of a satellite in km. In computation of H,
mean Earth's radius is assumed to be 6367.0 km;
Lat,d - current satellite's geographic latitude in degrees;
Long,d - current satellite's geographic longitude in degrees.
Longitude rises from 0 at Greenwich to East up to 360 degrees.
Geomagnetic coordinates:
B,Gauss - magnetic field strength at satellite's location, Gauss.
Computation of B is based on IGRF model for appropriate epoch;
L,Re - L-parameter at the satellite's location, Re.
Computation of the MacIlwain's parameter L, in Earth's radii,
is based on the SHELLG computer code;
InvLat,d - invariant latitude for satellite's location in degrees.
Computation of InvLat is based on pre-determined L-value;
MLT,h - magnetic local time at satellite's location in hours.
Computation of MLT is based on pre-determined geographic
coordinates and the IGRF model.
Non-geocentric spacecraft are supplied with the coordinate information given
in the HGI coordinate system, see its definition in the rah_to_hgi.txt file.
In addition, the spacecraft coordinates are also provided in their original
(after digitization and some manual smoothing) form, i.e. in RAH coordinate
system, see its description in the file rah_to_hgi.txt. All used terms are
listed below.
xHGI,km - current x-coordinate of spacecraft in HGI, in km;
yHGI,km - current y-coordinate of spacecraft in HGI, in km;
zHGI,km - current z-coordinate of spacecraft in HGI, in km;
R,ml_km - current distance between spacecraft and Sun in millions km;
aE-S-SC,d - current angle Earth-Sun- in degrees;
Hecl,ml_km - current height of a spacecraft above/under ecliptic in
millions km.
aEcl,d - current angle spacecraft-Sun- in degrees.
Everywhere, if applied, NODATA-filler is -9.999E+99.