4 research outputs found
On the computation of preliminary orbits for Earth satellites with radar observations
We introduce a new method to perform preliminary orbit determination
for satellites on low Earth orbits (LEO). This method works with
tracks of radar observations: each track is composed by
topocentric position vectors per pass of the satellite, taken at
very short time intervals. We assume very accurate values for the
range , while the angular positions (i.e. the line of sight,
given by the pointing of the antenna) are less accurate. We wish to
correct the errors in the angular positions already in the
computation of a preliminary orbit. With the information contained
in a pair of radar tracks, using the laws of the two-body dynamics,
we can write 8 equations in 8 unknowns. The unknowns are the
components of the topocentric velocity orthogonal to the line of
sight at the two mean epochs of the tracks, and the corrections
to be applied to the angular positions. We take advantage
of the fact that the components of are typically small.
We show the results of some tests, performed with simulated
observations, and compare this method with Gibbs'
and the Keplerian integral