I have been using Home Planet
(
http://fourmilab.ch/homeplanet/homeplanet.html) for a few days, and
have noticed some inaccuracies with the satellite tracking. For
example, the position of ISS (ZARYA).
Orbital tracking (
http://spaceflight.nasa.gov/realdata...ing/index.html)
returns this data:
37.6 S
38.9 E
Alt. 379.24 km
Home Planet's default SATELITE.SAT returns this data (rounded):
9.4 N
51.4 E
Alt. 288.89 km
And the current NORAD two-line element set from Celestrak
(
http://celestrak.com/NORAD/elements/stations.txt) returns this data
(rounded):
25.7 S
31.4 E
Alt. 378.60 km
Also note the conflicting positions of TERRA (
http://terra.nasa.gov/)
From SATELITE.SAT:
11.27 S
80.71 E
Alt. 655.57 km
From Celestrak (
http://celestrak.com/NORAD/elements/resource.txt):
64.33 S
33.94 E
Alt. 702.95 km
Now, my questions: Why don't both the SATELITE.SAT and Celestrak data
approximate the actual position of the ISS? How can I fix it so they
do? Which data sets are more trustworthy/accurate: the default
SATELITE.SAT or the sets from Celestrak? Is there a more accurate
source for two-line element sets?
Thanks in advance,
Zachary Antolak