Issue 3 | December 2011

GOCE satellitelaunched on 17 March 2009

In this issue:

Foreword 1

GOCE+ 1

4th international GOCE user workshop 2

GOCE mission status november 2011 2

Relase 3 GOCE gravity field solutions 2

The GOCE gravity field solutions:

DIR, TIM and SPW 3

Improvements of the geoid model

from the new solutions 3

Instruments performance and data quality 6

L1b processor update: quality assessment 7

Further publications 7

How to obtain GOCE data 8

Processing GOCE data 9

Staying up-to-date: the GOCE portal 10

Welcome to the third issue of the GOCENewsletter, describing the latest develop-ments of the Gravity field and steady-stateOcean Circulation Explorer mission and inparticular the third release of gravity fieldmodels based on GOCE data. The release 3of GOCE models includes data from the full

nominal mission from November 2009 toApril 2011. This Newsletter is being releasedon the occasion of the 2011 Fall Meeting ofthe American Geophysical Union, whichtakes place in San Francisco in early December 2011.

ForewordAll GOCE newsletters can be obtained from theGOCE web portal: http://earth.esa.int/GOCE

goCe+

Over the course of the recent months anumber of so-called GOCE+ projects havebeen kicked off by the European SpaceAgency. These "+" projects are aiming atadding to the original and well-definedbaseline products and nominal scienceobjectives addressed by the mission at thetime of its selection. Four major activitieshave been launched, supported by a feasi-bility study which may open the door tofuture and more involved activities in thecase of a positive conclusion. These are (i)HUG, Heights Using GOCE, a study into the

temporal variations in the gravity field withGOCE. Reports, conclusions and data productsfrom these studies will be made available tothe user community through the GOCE webportal.

use of GOCE-based geoid information in theconnection and unification of height systemdefinitions, (ii) GeoExplore, aiming at thepreparation and use of three-dimensionalgravity gradient signals for the explorationof sub-surface geophysical structures, and(iii) Air Density and Winds, aiming at the useof GOCE accelerometer data and ion thrusteractuation data for the improvement ofneutral density and wind models. The dura-tion of these contracts is between 18 and24 months. The feasibility study is a fast-track study into the possibility to detect

goce newsletter

→ esa’s gravity mission

Issue 3 | December 2011

2

goce newsletter

4th international goCe user workshop

The Fourth International GOCE User Work-shop was a major success. Nearly 200 scien-tists and a large number of members of thepress participated in the event that washosted by the Technical University of Munich,31 March and 01 April 2011. The new(Release 2) GOCE geoid was featuring inmajor newspapers across Europe and the

published and available on the GOCE webpages as well as ESA publication SP-696.See also http://www.goce2011.organd http://www.spacebooks-online.com/product_info.php?cPath=104&products_id=17254

scientific discussions highlighted the excel-lent performance of the GOCE missions aswell as the need to organise further meet-ings to bring the various application disci-plines together to discuss GOCE missionexploitation in the broadest sense. Theproceedings including the workshop recom-mendations and conclusions are meanwhile

goCe mission status november 2011

relase 3 goCe gravity field solutions

The GOCE satellite and its payload are inexcellent condition and continue to deliveruninterrupted and high-quality data sets.The configuration of both payloads and allsatellite subsystem is stable and hasremained unchanged since February 2010.The orbital altitude of 254.9 km and therespective 61 days repeat cycle have beenkept constant since launch. However and inparticular during the last three months asignificant increase in atmospheric drag hasbeen experienced. Compared to the earlydays of the mission the average drag hasgone up by a factor of five which so far canbe accommodated by GOCE’s electric propul-sion system. Given the outstanding perform-ance of the propulsion system theatmospheric density predictions for the2012-2013 maximum of the current solarcycle do not currently indicate the need for achange in orbital altitude. At the currentlevel of Xe propellant consumption GOCE canbe kept operational until the end of 2013.The orbital plane – initially with an ascendingnode at the equator at 18:00 local time – hasdrifted to 18:55 at the beginning of November

have been developed and implementedduring the reporting period since the issueof Newsletter #2. A major change in the angular rate recon-struction has been developed. Quaternionsare fused with input from all available startrackers (up to 3) with the GRACE methodand the Kalman filtering has been replacedby a Wiener filter. Significant improvementsin the trace error are visible in the lower partof the measurement bandwidth. Secondly,the relevant elements of the Instrument Cali-bration Matrix ICM are linearly interpolatedbetween two instrument calibrations takingbetter into account the small long term driftof the instrument electronics. Reprocessingof all data accumulated during the missionwill be finished by January 2012.

A short interruption of science operationsoccurred on late 9 November 2011 when asoftware crash of the computer controllingthe ion propulsion system caused the satel-lite to leave drag free mode. Nominal scienceoperations could be established within lessthan 2 days.

2011. This is due to the delta between theactual orbital altitude and the sun-synchro-nous altitude designed before launch andsecondly, to the inclination drift caused by themoon and sun. As a consequence, the eclipsefree periods shrink to short time spansaround March each year. The maximum dura-tion of individual eclipses however does notincrease. An industrial review confirmed thecapability of the power subsystem to copewith the changes of the orbital plane wellbeyond the currently foreseen mission life-time. Excellent gradiometric performanceduring eclipses has been demonstratedalready in the early mission phase.

Ten measurement cycles of 61 days durationeach have been performed by the end ofOctober 2011. Each cycle provides a separa-tion of adjacent ascending node crossings atthe equator of 40 km. Shifting individualrepeat cycles in respect to each other isbeing continued to achieve a denser groundcoverage pattern.

Improvements to the Level 1 data processing

The third generation of the gravity field solu-tions have been released on November 07,2011. These new solutions are based onthe data available between November 2009to June 2011(effectively 12, months after reduction ofdata gaps and calibration phases). The so called direct and time-wise numer-ical solutions are available, both representingsatellite-only gravity field solutions. Theproducts associated with these solutions,are: • Direct solution :

GO_CONS_EGM_GOC_2__20091101T000000_20110419T235959_0001.TGZ

• time-wise solution:GO_CONS_EGM_GOC_2__20091101T000000_20110430T235959_0001.TGZ

plain ASCII format from the GOCE webportal, see: http://earth.esa.int/object/index.cfm?fobjectid=8047(Time-wise solution)http://earth.esa.int/object/index.cfm?fobjectid=8049 (Direct solution) or from ICGEM.

A first generation of GOCE gravity field-models, based on 2 months of data (1 Nov2009 through 31 Dec 2009), was released atESA’s Living Planet symposium in Bergen,Norway, July 2010. The second generationwas subsequently released in March 2011.

A third solution, so-called space-wise solu-tion, will be released later on.

These new solutions are available free ofcharge, through the usual data services,EOLI and the GOCE Virtual Online Archive(see below). Full error variance-covariance matrices forthese models are available and may bedownloaded from the GOCE Virtual OnlineArchive, where a more complete descriptionof the models characteristics may also befound.

A subset of these data, the models’ gravityfield spherical harmonics coefficients, hadalready been released by ESA in February2011. They may be directly downloaded in

3

Three different solutions for the gravity fieldare being released by ESA, representing theTime-wise solution (TIM), the direct solution(DIR) and the space-wise solution (SPW).

The time-wise solution is inferred from GOCEdata exclusively, i.e. it does not containgravity field information through a back-ground reference model. Therefore, it isrepresentative of the GOCE mission perform-ance and constitutes an independent meansof comparison to other models.

The direct numerical solution, in contrastwith the time-wise one, has beenconstructed taking prior gravity field infor-mation through a background referencemode. As such, it incorporates data fromother satellite missions, such as GRACE. Thelow degrees of the direct solution are conse-

quently more accurate than those of thetime-wise solution. None of these two new solutions incorporatesurface data or airborne data in any way.

The Space-wise (SPW) model makes use ofboth satellite tracking data, derived from theon-board GPS receiver, and gravity gradientsobserved by the on-board electrostaticgradiometer. Reduced dynamic orbits areused for geo-locating gravity gradients.EGM2008 is used for degree variance model-ling and for error calibration of the estimatedgravitational potential along track, thusaffecting the low degrees of the solution. Asmentioned above, the third generation SPWmodel has not been released together withthe DIR and TIM models. It will be releasedas soon as it has been produced and vali-dated by the relevant science teams.

During the extended mission, theprocessing team behind the Space-wisesolution plans to deliver gridded data in alocal geographical reference frame. Gridsmay either be referred at mean satellitealtitude, returning the gravitational poten-tial and its second order derivatives thusrepresenting the original information fromMission data, or, through downward contin-uation, at ground level, returning the diagonal component of the gravity gradienttensor. External information, such as otherindependent global models based on satel-lite and/or ground data, may be easily integrated in gridded representations.Easier integration in geophysical applica-tions will also result. High resolutions maybe achieved by gridding.

time wise model characteristicsand validation results

One of the key characteristic of the time-wiseprocessing method is the attempt to modelthe stochastic properties of the input data asrealistically as possible. Concerning gravitygradiometry, the total data period fromNovember 2009 to April 2011 is split into 17segments (cf. Fig 1, bottom) according tochanges in the error behaviour. Figure 1 (left)displays the ARMA filters used for buildingthe metric of the normal equations for these17 sub-segments, showing time-variations ofthe gradiometer performance mainly below

and in the lower measurement bandwidth.The resulting R3 time-wise model iscompared to the previous results of R1 and 2in the form of gravity anomaly differences toEGM2008 (Figure 3, top row) at degree/order200. They show persistent deviations inregions where terrestrial gravity dataincluded in EGM2008 are known to be of lowquality, while the noise level over well-surveyed areas successively decreases.

Figure 3 shows the results of covariance prop-agation to geoid height errors based on thefull parameter variance-covariance matrix(VCM) complete to degree/order 200. Theimprovement due to a larger amount of GOCE

data is according to Gaussian √N rule. Thecharacteristic feature south of Australia is dueto the fact that spurious ascending tracks ofVYY data have been excluded.

Several validation test show that the formalerrors are a very good estimate of the realerrors of this solution, which is due to thefact that the stochastic behaviour of all inputdata types is modelled realistically in theframe of the L2 adjustment. Figure 2 showscumulative geoid height (left) and gravityanomaly errors (right) of the 3 TIM releases.The accuracy is 4.6 cm / 1.3 mGal atdegree/order 200 (100 km half wavelength)for the release 3 model.

Fig. 1Stochastic model for VZZ component.

Fig. 2Cumulative geoid height (left) and gravity anomaly errors (right).

Issue 3 | December 2011goce newsletter

new direct, time-wise and space-wise gravity field solutions

improvements of the geoid model from the new solutions

Direct model characteristics and validation results

The following plots show the main charac-teristics of the GO_CONS_GCF_2_DIR_R3model in comparison to the release 2 modelof the direct approach (GO_CONS_GCF_2_DIR_R2) and EGM2008. In Fig. 4 the spectral behaviour of DIR_R3 isshown. The formal error of DIR_R3 (yellow)is significantly smaller compared to that ofDIR_R2 (purple). Furthermore, the cumulatederror of DIR_R3 at degree 200 (expressed interms geoid height) is 3 cm (red) comparedto 5 cm for DIR_R2 (brown) which means animprovement of about 40% of DIR-R3 versusDIR-R2.

In the long wavelengths range betweendegrees 20 and 70 the DIR-R3 is closer toEGM2008 compared to DIR-R2. This iscaused by the stronger impact of GRACE inDIR-R3 versus DIR-R2. Furthermore, in the short wavelength rangebetween degree 160 and 240 DIR-R3 is alsocloser to EGM2008 compared to DIR-R2. Thismeans an decrease of the noise (c.f. also Fig.5, bottom vs. top) as well as an improvedsignal content in DIR-R3 in comparison withDIR-R2 (c.f. Tab. 1)

4

The comparison of global geoid height differ-ences in Fig. 2 for DIR-R3 (bottom) and DIR-R2 (top) minus EGM2008 shows a significantnoise reduction for DIR-R3 versus DIR-R2, forinstance for the entire southern hemisphere

and in particular south of Australia. Thiscorresponds also to the statistical numbers“wrms about mean / min / max” as given inthe plots. Please note that these numbersinclude the polar caps.

Issue 3 | December 2011goce newsletter

Fig. 3Gravity anomaly differences to EGM2008 (top row) and geoid height errors propagated from the parameter VCM (bottom row), both at degree/order 200

Fig. 4Spectral behaviour of GO_CONS_GCF_2_DIR_R3 in comparison with the DIR-R2 model. This plot givesthe difference degree amplitudes of DIR-R3 and DIR-R2 to EGM2008 (green resp. blue) and theerror degree amplitudes resp. the cumulated errors for both models

5

Issue 3 | December 2011goce newsletter

Geoid height differences between the twoDIR-models themselves are given in Fig. 6.The thereabouts visible patterns in thenorthern and southern polar regions reflectthe noise reduction of DIR-R3 versus DIR-R2as already indicated in Fig. 5. Furthermore afew significant signal patterns in particularover Central Asia and the Himalayas (redcircle) indicate an additional signal content inDIR-R3 versus DIR-R2.

GPS/Leveling comparisons as given in Tab. 1confirm the significant improvement of DIR-R3 in comparison with the DIR-R2 model. Theobtained GPS/Leveling RMS values for DIR-R3 are significantly smaller than for DIR-R2.

Tab. 1: GPS/Leveling tests for the DIR-R3model versus DIR-R2. This table gives theRoot Mean Square values (cm) about meanof GPS-Leveling minus model-derived geoidheights for five GPS/Lev data sets (numberof points in brackets). Both models weretaken up to d/o 240 and filled up byEGM2008 to d/o 360.

Fig. 5Global geoid height differences (meter, spatial grid resolution 0.75° x 0.75°, maximum degree/order240) versus EGM2008 for DIR-R2 (top) and DIR-R3 (bottom)

Fig. 6Global geoid height differences (meter, spatial grid resolution 0.75° x 0.75°, maximum degree/order240) for DIR-R3 versus DIR-R2

DIR-R2 DIR-R3

USA 37 35(6169)

Australia 33 28(201)

Germany 28 21(675)

Canada 31 28(1930)

Europe 34 30(1234)

For all data released, reports on instruments,spacecraft or processing issues affecting thequality of data may be found on the GOCEQuality Control (QC) web page: http://earth.esa.int/goCe/ → “Level 1b QC

The GOCE QC page provides information onthe performance of GOCE's ElectrostaticGravity Gradiometer (EGG) and Satellite toSatellite Tracking Instrument (SSTI), throughdaily and monthly reports. Information are provided in several formatsand views, such as:

• egg summary tableSynthetic view for EGG data quality

• ssti summary tableSynthetic view for SST data quality

• monthly reportsReference QC reports for all released data.

• reportsOther Reports/Announcements of generalinterest.

November 2009 through May 2011 reportsare available to date.

Summary tables, an example is shown inFigure 7, present a view of the overall instru-ment’s data status.Events are colour coded, indicating satelliteoutages, calibrations or special events (anynon-routine event). Special events cells areusually clickable, for access to detailed analysis.

Data gaps on EGG are most often a result ofprocessing issues on-ground. In-flight calibration operations for InverseCalibration Matrix determination is alwaysconnected with, EGG data unavailability (24hours, usually).

instruments performance and data qualityRelevant data loss or corruption haveresulted only for the major spacecraft anomalies, so far:

• 12/02 to 1/03/2010: Command and DataManagement Init (CDMU)-A failure andswitchover to the redundant CDMU-B.During the anomaly no EGG data are avail-able. Some of the SSTI data are missing(for the details see the web February 2010monthly QC report).

• 20/03/2010: EGG control SW anomaly. Agap of 197 seconds in EGG datasetsresults, with consequent, Kalman filterreinitialization.

• 30/06/2010: Sudden interruption of thecommunication between Ion PropulsionControl Unit (IPCU) and CDMU occurred atUTC. This forced a fallback to Fine PointingMode (FPM). Nominal operations wererestored on 02/06/2011.

• 02/01/2011: SSTI failure, divergence ofattitude control in DFM_FINE, commandedfallback to Coarse Pointing Mode (CPM) atUTC12:28. EGG was switched off. Nominaloperations was restored on 19/01/2011.

• 08/02/2011: Gradiometer and Accelerom-eter Interface Electronics Unit(GAEIU) watchdog triggering at05:46 and commanding of theEGG to Acquisition/Science.Science operation was resumedon 10/02/2011.

• 09/02/2011: EGG Power Cycleat 14:38. Gap of 94 seconds inproduction.

• 10/02/2011: EGG reconfigura-tion after the anomalies of 8thand 9th of February. Nominaloperations restored at UTC07:15.

Fig. 8Beam Out event, as seen in common mode

accelerations data.

Other special events are usually related to: • Beam Outs from the Ion propulsion.

Impact on data is limited to the eventitself, not propagating forward (see Figure8). Fifty six Beam Out events haveoccurred, so far.

• Control Voltages anomalous oscillations(see Figure 9): Anomalous oscillations werefound in the control voltages data setwhich lead to issues in the downstreammeasurement data sets as well such asgradients. These anomalous oscillationshave impacts on performance and havesmall time duration, in the order of fewseconds. Generally these oscillations haveno long term impacts on the science dataand their occurrence is random and notrelated to a precise time of day or month.The root causes of the events are not yetunderstood. Since November 2009, 16events occurred.

Beam Out events alter common mode accelerations data, see Figure 8.

Issue 3 | December 2011goce newsletter

Fig. 7Summary table for EGG instrument. See earth.esa.int/GOCE/ → “Level 1bQC” → EGGSee earth.esa.int/GOCE/ → “Level 1b QC” → EGG

6

Fig. 9CTR oscillation in component A6_Z1

7

L1b processor update: quality assessment

An updated version of the EGG processor wassuccessfully installed at PDGS in November2011.The major upgrades are:

• Quaternion fusion by GRACE method of upto three quaternions.

• Angular rate fusion via convolution in timedomain using the Wiener filter approach:this upgrades impacts the EGG_NOM_1bgradiometer angular rates (EGG_GAR) Meas-urement Data Set (MDS).

• Generation of augmented quaternions bycombination of fused quaternions andangular rates (new EGG_IAQ MDS)

• Calibration matrices interpolated linearly toeach processing epoch

The new processor leads to performanceimprovements mostly in the lower frequen-cies of the gradients trace.

With the new processor release the traceerror trace is no more influenced by which STRis used for the attitude control: the oldprocessor version had worsened performancein the lower part of the measurement band-width when the STR1 is used while in thenewest one, due to the use of the virtual startracker (STR), this effect is no more present.

Fig. 11Trace PSDs computedwith the old processorversion using the twoSTRs (top) and trace

PSDs computed with thevirtual STR (bottom)

Fig. 10Trace PSD based on theold and the newest EGGprocessor

Further publications

A special issue of the Journal of Geodesy hasbeen released that is dedicated to GOCE, see

http://earth.esa.int/object/index.cfm?fobjectid=7995

Issue 3 | December 2011goce newsletter

How to obtain goCe data

Table 2AvailableGOCEproducts

Level Product single product span

Level 1b EGG_NOM_1b 1 orbit

Description

Nominal Gradiometer Instrument data

SST_NOM_1b 1 orbit Nominal SSTI Instrument (GPS) data

SST_RIN_1b 1 orbit Nominal SSTI Instrument (GPS) data inRINEX format

EGG_NOM_2 1 day Calibrated and corrected gravity gradientsin the gradiometer reference frame

Level 2

EGG_TRF_2 1 day to 1 month Calibrated and corrected gravity gradients inthe terrestrial reference frame

SST_PSO_2 1 day Precise Science Orbits

SST_AUX_2 point wise time variable gravity field due to non-tidalmass variations

EGM_GOC_2 > 2 months Gravity solution. First and Second Generationsolutions are available with three differentprocessing techniques: direct numericalsolution, Time-wise and Space-wise solutions.

Level 2 gravitysolutions

EGM_GVC_2 > 2 months Variance/covariance matrices associated tothe Gravity solutions. Available only throughthe Virtual Online Archive.

Fig. 12The GOCE Virtual Online Archive at http://eo-virtual- archive1.esa.int/Index.html

available datasetsAvailable GOCE Level-1b and Level-2 datasets are listed in Table 1.

8

provide an account with ordering privileges. GOCE data will then be accessible eitherthrough GOCE’s Virtual on-line Archive(http://eo-virtual-archive1.esa.int/index.html)or through ESA’s Multi-Mission archive, EOLI-SA(see http://earth.esa.int/eoLi/eoLi.html).

From EOLI-SA, products are made availableeither as single products or as Global products,collecting one week of data each. No quota limitation applies but orders may be limited toa maximum of 20 products. Global (weekly)products should be used for larger orders, inplace of single products.

EOLI users receive, for each order, a link fordownloading the data via ftp, while VirtualArchive users can directly download datathrough http, without the need of submittingorders. EOLI interface offers, however, moreflexibility and tools for data selection. Variance/Covariance matrices (EGM_GVC_2)are only available through the GOCE VirtualArchive. All details and up-to-day news on GOCE dataavailability can be found on GOCE’s portal(http://earth.esa.int/goCe).

Data accessGOCE data access is open and free of charge,in line with the new ESA Earth Observationpolicies on free datasets. More detailed information on ESA Earth Observation dataaccess may be found at: http://earth.esa.int/dataproducts/accessingeodata. In order to access GOCE data, users need toregister via the WWW site: http://eopi.esa.int/registration. Users may also contact the ESA’s Help andOrder Desk (eoHelp@esa.int), for guidanceon the registration process. Once users are registered, ESA’s helpdesk will

Issue 3 | December 2011goce newsletter

Fig. 13The ESA Multi Mission

Archive EOLI-SA

9

University of Munich 31 March-1 April 2011. GUT release 2.1 is the one currently distribu-ted to users via web or DVD shipment, andessentially a bug fix release.

The release of the variance/covariance tool isplanned simultaneously with the AGU confer-ence in San Francisco, USA, during the week5-9 December 2011.

The updated package will feature a newversion of the GUT Data Package, includingthe third GOCE Gravity Field Solutions (TIMand DIR) and the 2011 CNES-CLS Mean SeaSurface (in addition to DTU 2010 Mean SeaSurface). A single tool for handling the GOCE vari-ance/covariance matrices and for computingthe Geoid Height error variance and covariancefunctions will be part of the new release, along-awaited for feature. At AGU, this newrelease of GUT will be advertised with thedistribution of DVDs and promotional posters.The improvement of GUT is made possiblethanks to a solid and increasing user commu-

nity base on which GUT can count: betweenMarch 30th and November 2011, there havebeen 440 download requests, 252 of whichcoming from single email account. Thatmakes for an average of two effective down-loads per day.

In parallel, a user survey has been running tocollect the users’ opinion on the toolbox andsuggestions for future changes.For more information, please check the GUTown website, also reachable directly fromGOCE’s web portal:

http://earth.esa.int/gutFor any request of support, please write togut.info@plod.esrin.esa.it.

The GUT (GOCE User Toolbox) is the result ofthe work of a team of European research insti-tutes and industries led by Danish TechnicalUniversity Space (DTU Space) under ESAcontract. The objectives of the project are todevelop a toolbox that facilitates the use,viewing and post-processing of GOCE Level 2mission data and to pursue the research inthe fields of geodesy, oceanography and solidEarth physics, while exploiting the newlyreleased GOCE dataset.The GUT software is a command-lineprocessor that has been designed for users atall levels of expertise. For the novice user, pre-built workflows allow the rapid computationof geophysical parameters, including geoidheights, gravity anomalies and ocean meandynamic topographies in a single step, withvery little user input required. More experi-enced users can generate their own work-flows for enhanced or more specialisedprocessing.

Version 2.0 of the toolbox was released for the4th GOCE User Workshop held in Technical

gutGOCE USER TOOLBOX

gutGOCE USER TOOLBOX

Issue 3 | December 2011goce newsletter

parsing tool for extracting the datasets ofinterest, ESA provides two basic tools forprocessing L1b and L2 data: • XML Parser for Level 1b and Level 2 data • Basic Matlab routines for specific L1b data.

The XML parser runs on Mac, Windows andLinux platforms.

Processing goCe data

Both XML parser and the Matlab routines maybe downloaded from the GOCE website, underthe right-menu bar entry: “Key Resources” (seeFigure 16):http://earth.esa.int/object/index.cfm?fobjectid=7042http://earth.esa.int/object/index.cfm?fobjectid=7530

L1b and Level 2 product readersGOCE data conform to the Earth Explorers FileFormat, which is based on XML. Product handbooks for both Level-1b andLevel-2 products are available from the GOCEportal, containing most of the informationneeded for understanding GOCE’s data formatsand contents. While each user is free to develop its own

the gUt software suite. version 2.1 now contains variance covariance tool

Due to the major update of the L1b processorall GOCE data of the nominal mission shall bereprocessed, see figure to the right.The GOCE Virtual Archive will offer the possi-bility to compare old and reprocessed data asthe data will be hosted in different folders. ViaEOLI-SA only the reprocessed data will beaccessible. Regular news items published onthe GOCE portal will inform about the currentstatus of the reprocessing activity which isplanned to be completed by Spring 2012.

Fig. 14Green part has already beenreprocessed and partly distributed to the user community.

10

Contact:european space agency - goce newsletterESRIN | Frascati (Rome) | Italyhttp://earth.esa.int/goce

Copyright © 2011 European Space Agency

on behalf of the goCe team rune Floberghagen

rune.floberghagen@esa.int

Issue 3 | December 2011goce newsletter

getting help ESA’s Earth Observation User Services inESRIN, Italy, is the entity ensuring a user-friendly interface between the satellite systemand the data users. Services provided to usersinclude:

• Help services from the EO Help Desk team• Order Handling by the Order Desk• Mission planning and production planning • Maintenance of catalogues and ordering tools• On-line information services: (Earthnetonline, EO Portal and Disasters Charter)

All these interfaces are further described onGOCE’s web site.

The GOCE portal is the single and comprehen-sive access point for all GOCE-related informa-tion, resources and data access. Please, visit it regularly for announcements and updates.

http://earth.esa.int/goCe/

Fig. 15The GOCE main portal athttp://earth.esa.int/GOCE

staying up-to-date: the goCe portal