sidtm= true sidereal time
n    = 1 receiving site coordinates determined
n    = 2 sending site coordinates determined
nvel =-1 position and nothing else determined
nvel = 0 position determined
nvel = 1 position and velocity determined
nvel = 2 position, velocity and acceleration determined
nvel = 3 position,velocity,acceleration and jerk determined
norm = 0 normal to site not determined
norm = 1 normal to site determined (referred to mean
equinox and equator of reference epoch)
norm = 2 normal to site determined and partial
derivatives w.r.t. site coordinates determined
even if lsite(1-3)=0
(for solid body tides or fluid displacements)

ksite(n)   =0   for spherical polar coords.
ksite(n)   =-1  for cylindrical polar coords.
xsite(.,n) =position,velocity,acceleration of site n
(distance and time units are light-seconds and
seconds)
sitnrm(.,n)=unit normal to spheroid at site n
pstlat(.,n)=partial derivatives of site position and
velocity with respect to center of earth
latitude in radians (if ksite(n)=0)
or else with respect to rs=z (if ksite(n)=-1)
pstlon(.,n)=partial derivatives of site position and
velocity with respect to longitude in radians