[amsat-bb] Unitec-1 prediction data at T+ 00.48.19

G0MRF@aol.com G0MRF at aol.com
Sat May 15 09:11:24 PDT 2010

Hi all.
Does anyone know how to convert the spatial co-ordinates and 'velocity  
vectors' of Unitec-1 at separation into something that gives pointing data for  
elevation and azimuth.
I can see it will be at an altitude of 6600km 48 mins and 19 seconds after  
its 21.44UTC launch, but converting the distances from the X Y and Z 
references  is unfamiliar.
David G0MRF
Table. UNITEC-1 Separation Prediction (as of 2010.5.12)      Separation  
timing 2901.000  sec  >>time  after the launcher liftoff) >>17  May 2010, 
22:32:35 UTC  Inertial velocity 8957.4 m/s  Elevation for inertial flight 47.627 
deg  Azimuth for inertial flight 96.499 deg  Geocentric distance 12999.796 
km  Altitude 6627.232 km  Inertial  coordinate position: X 4630586  m  
Inertial  coordinate position: Y -10174686  m  Inertial  coordinate position: Z 
-6635370  m  Inertial  coordinate velocity: X 7672.0  m/s  Inertial  
coordinate velocity: Y -2377.4  m/s  Inertial  coordinate velocity: Z -3965.3  m/s
Definition of position and velocity,  Inertial coordinate system 
Origin:Earth centre
X axis:Intersection of  equator plane and meridian that contains the 
Greenwich at a nominal lift off  time. 
Y axis:Right hand system (on equatorial plane)
Z axis:North  pole

More information about the AMSAT-BB mailing list