Solar System Bodies with SRT


The Sardinia Radio Telescope (Bolli 2015) is a 64-metre radio telescopes which operates from 300 MHz up to 100 GHz.

Given that the requested pointing accuracy at its highest operating frequency is about 1 arcsec (Poppi 2010), high accuracy ephemerides are necessary to observe planets and other solar system bodies and spacecraft. Among the possible solutions to get a suitable ephemerides generator, the SPICE toolkit of the NASA’s Navigation and Ancillary Information Facility NAIF allows the best accuracy (note: insert accuracy).


Topocentric observer location

The parallax due to the observer location on the Earth surface must to be taken into account for Solar system bodies. SPICE allows to fix the posiont of the observer and its reference frame. The first step needed to calculate the The reference frame allowed for the coordiantes of the bodies to be given to the control system is the ICRF/J2000. void spkezr_c ( ConstSpiceChar *targ, SpiceDouble et, ConstSpiceChar *ref, ConstSpiceChar *abcorr, ConstSpiceChar *obs, SpiceDouble starg[6], SpiceDouble *lt ) To observe the solar system body from a place on the surface of the Earth, it is necessary to know the coordinate

begindata SITES = ( ’SRT’)
SRT_CENTER=399 SRT_IDCODE=399072 SRT_FRAME=’ITRF93’ SRT_XYZ= (4865.18338710, 791.92221630, 4035.13596770) SRT_EPOCH = @2000-JAN-01/00:00:00 SRT_UP = ’Z’ SRT_NORTH = ’X’
SRT ITRF93 SRT_DXYZ=(0.02105,0.02227,0.01762)


The system could be made of two component:

  • A trajectory generator component, SolarSystem Component:

  • Kernel Handler

A component which handles the kernel files: To Download new kernels given the id of the body or the probe To Store in the database the path to the kernel file Give the trajectory generator comp, the reference of the ephemeris file

Solar System and Space Missions Components

HORIZON gives a web based interface and a telnet link. The first one is suitable for interactive session,the latter is more appropriate for automatic operation. Telnet session can be controlled with proper python libraries (telnet lib?)