compensation de l'effet Doppler

CONT: Utilisez un oscillateur externe tel que le VXO F1BBU003 avec celui-ci vous obtiendrez une excellente stabilité avec un réglage continu de la fréquence ce qui peu être utile pour la compensation de l'effet doppler pour le suivi d'un satellite.

CONT: As you probably know, the GHRS automatically corrects observations for the effects of the motion of the HST spacecraft. This correction is done in real time as an exposure is in progress. Every minute a new shift is calculated and if necessary a change in the deflection of the spectrum is made. These onboard corrections cannot be removed after the fact except as an overall shift of the spectrum, but the net doppler compensation applied is stored in the data header. As in the case of a heliocentric correction to radial velocity, the doppler compensation is calculated from the position of the object relative to the vector of motion of the spacecraft.
CONT: Probably an automatic Doppler effect compensation is used: when approaching the object, the questioning signal becomes shorter and the impulse sequence faster. The sound volume can also be varied in order to detect more distant objects or sound-absorbing objects.

OBS: Este método es utilizado por el sistema GSM (sistema Global de Comunicaciones Móviles) de telefonía móvil (ver: efecto Doppler).