UNISAT program was established at the Scuola di Ingegneria Aerospaziale of University of Rome “La Sapienza” in late nineties. In the framework of this project Professors, researcher and students of GAUSS (Gruppo di Astrodinamica dell’Università degli Studi “La Sapienza”), coordinated from Professor Filippo Graziani, have already designed, manufactured and launched in orbit three microsatellites. UNISAT-3 was launched in July 2005 from Baykonour Cosmodrome. Telemetry data are regularly received from SPIV (San Pietro In Vincoli) ground station. UNISAT-3 attitude is passively stabilized exploiting permanent magnets and magnetic hysteresis rods. The paper deals with UNISAT-3 attitude determination, using real time telemetry data received when the satellite is in the ground station visibility. Data collected during this portion of the orbit include three solar panel currents and voltage and three axes magnetoresistive magnetometer readings. The solar arrays are used as coarse sun sensor. Many disturbances such as Earth albedo and temperature affect the measurements whereas the magnetometer readings are affected by unknown biases due to the on-board magnetic stabilization system and residual magnetic dipole. Practical considerations and mathematical techniques to smooth rough data taking into account perturbing effects, noise and bias affecting measurements are discussed. After data reduction the q-method has been exploited to evaluate attitude. Achieved accuracy for attitude estimation has been evaluated on the order of 10 degrees.
Unisat-3 Attitude Determination / F. Santoni; F. Piergentili. - STAMPA. - (2005). (Intervento presentato al convegno XVIII Congresso Nazionale A.I.D.A.A tenutosi a VOLTERRA nel 19-22 Sept. 2005.).
Unisat-3 Attitude Determination
PIERGENTILI, FABRIZIO
2005
Abstract
UNISAT program was established at the Scuola di Ingegneria Aerospaziale of University of Rome “La Sapienza” in late nineties. In the framework of this project Professors, researcher and students of GAUSS (Gruppo di Astrodinamica dell’Università degli Studi “La Sapienza”), coordinated from Professor Filippo Graziani, have already designed, manufactured and launched in orbit three microsatellites. UNISAT-3 was launched in July 2005 from Baykonour Cosmodrome. Telemetry data are regularly received from SPIV (San Pietro In Vincoli) ground station. UNISAT-3 attitude is passively stabilized exploiting permanent magnets and magnetic hysteresis rods. The paper deals with UNISAT-3 attitude determination, using real time telemetry data received when the satellite is in the ground station visibility. Data collected during this portion of the orbit include three solar panel currents and voltage and three axes magnetoresistive magnetometer readings. The solar arrays are used as coarse sun sensor. Many disturbances such as Earth albedo and temperature affect the measurements whereas the magnetometer readings are affected by unknown biases due to the on-board magnetic stabilization system and residual magnetic dipole. Practical considerations and mathematical techniques to smooth rough data taking into account perturbing effects, noise and bias affecting measurements are discussed. After data reduction the q-method has been exploited to evaluate attitude. Achieved accuracy for attitude estimation has been evaluated on the order of 10 degrees.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
