Hi Ronan,
I advanced a bit but am now stumbled on a problem. The orbit looks nice but it’s not correct. Here is a mwe of what I’m doing with the latest TLE for the AQUA satellite. I checked on the OceanColor site, a site on the web and my Matlab program that also uses SGP4 propagator and the results are different from the one I get with.
tle1 = "1 27424U 02022A 21245.83760660 .00000135 00000-0 39999-4 0 9997"
tle2 = "2 27424 98.2123 186.0654 0002229 67.6025 313.3829 14.57107527 28342"
tle = read_tle_from_string(tle1, tle2, true)
orbp = SatelliteToolbox.init_orbit_propagator(Val(:sgp4), tle[1])
times = DateTime("2021-09-02T13:30:00"):Second(60):DateTime("2021-09-02T14:30:00")
n_pts = length(times)
out = Matrix{Float64}(undef, n_pts, 4)
for n = 1:n_pts
t = datetime2julian(times[n])
r, = SatelliteToolbox.propagate_to_epoch!(orbp, t)
out[n,1], out[n,2], out[n,3], out[n, 4] = r[1], r[2], r[3], t
end
# Convert to lon lat. Must have GMT.jl to do this
track = mapproject(out, E=true, I=true)
Do you spot any mistake in my code?
The track plots like
imshow(track, proj=:Robinson, region=:global, coast=true)
From the OceanColor site (and the Matlab program too) the first point of this track should be in
