Minimize GOCE Re-Entry Phase special dataset


A special dataset, covering the 20 days of the GOCE re-entry phase, from 20 October 2013 to the end of Mission, 11 November 2013, is available through the GOCE Virtual Online Archive.

GOCE de-orbiting special data include all the nominal Level-1b data, that is the EGG gradiometer data, the orbital data from the SSTI GPS receiver and the attitude information from the Star Trackers, all the nominal Level-2 data (except for the EGG_TRF_2), and a special set of data with further dynamical and environmental information such as on-board magnetometer measurements of the Earth's Magnetic Field, currents actuating the magnetic torquers, and linear accelerations sensed by the six ultra-sensitive accelerometers.

GOCE de-orbiting was started at an equatorial altitude of 224 Km, on 20 October 2013, as the Ion thruster was switched off and GOCE was left to free-fall in the atmosphere. GOCE eventually disintegrated in the atmosphere on 11 November 2013, at the extremely low altitude of around 115 km.

During GOCE de-orbiting and re-entry, all instruments continued working almost to the end, making this dataset unique.

The Gradiometer has performed nominally up to the point when the drag levels reached 80 mN, at a mean altitude of 181 km, on 7 November 2013. After that, measurements start being affected by saturation are but still usable, limited to the portion of the orbit where the accelerometers are still within their dynamic range. An increasing portion of the orbit is eventually saturated as the atmospheric density increases, with the decreasing spacecraft's altitude.
Acceleration measurements from the Drag-Free control (DFACS) channel are available almost to the end, down to an altitude of around 154 Km, on 10 November 2013.

Both on-board GPS receivers, the SSTI-A and B instruments, remained ON in measurement mode until the very end of Mission. Neither SSTI shows significant worsening of performance during orbital decay.

This new set of data is expected to be a valuable asset to the researchers involved in re-entry dynamics, geo-magnetism and thermospheric studies.

Data available

GOCE De-orbiting data Data availability Notes
Level-1
EGG_NOM_1b 2013-10-21* 2013-11-10** *Acquisition Mode processing
** Up to 2013-10-30 unsaturated data. After this date, saturation sets in.
By 2013-11-07 all is saturated. Use DFACS accelerometers data instead.
SST_NOM_1b 2013-10-21 2013-11-10 17:15  
SST_RIN_1b 2013-10-21 2013-11-10 17:15  
STR_VC2_1b 2013-10-21 2013-11-10 17:15  
STR_VC3_1b 2013-10-21 2013-11-10 17:15  
AUX_NOM_1b 2013-10-21 2013-11-10 17:29 Not baseline public data
Level-1 Special Dataset
DFACS Accelerometers 2013-10-21 2013-11-10 14:39 Not in EEF file format
Magneto-Torquers Currents (MTR) 2013-10-21 2013-11-10 22:46* Not in EEF file format
Magnetometers data (MAG) 2013-10-21 2013-11-10 22:46* Not in EEF file format
Level-2
EGG_NOM_2 2013-10-21 2013-11-05 23:59  
SST_PSO_2 2013-10-21 2013-11-05 23:59  
SST_AUX_2 2013-10-21 2013-11-07 18:00  

Contacts

To send general enquires about the data, their quality and availability, please contact the ESA Earth Observation Helpdesk