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    <NumericalData>
        <ResourceID>spase://CDPP/NumericalData/AMDA/MEX/ELS/mex-els-all</ResourceID>
        <ResourceHeader>

            <ResourceName>electron energy spectra : 16 anodes</ResourceName>

            <ReleaseDate>2016-10-15T09:46:00</ReleaseDate>  
            <Description>Level2 data. This dataset is generated directly from the MEX telemetry with IRAP software</Description>
            <Acknowledgement>The Mars Express ASPERA team, S.Barabash, Swedish

Institute of Space Physics, PI, and the European Space Agency</Acknowledgement>
            <Contact>

                <PersonID>spase://SMWG/Person/Stas.Barabash</PersonID>

                <Role>PrincipalInvestigator</Role>
            </Contact>

            <Contact>
                <PersonID>spase://CDPP/Person/Rudy.Frahm</PersonID>
                <Role>GeneralContact</Role>
            </Contact>
            <Contact>
                <PersonID>spase://CDPP/Person/Elena.Budnik</PersonID>
                <Role>TechnicalContact</Role>

            </Contact>           

        </ResourceHeader>
        <AccessInformation>
            <RepositoryID>spase://SMWG/Repository/CDPP/AMDA</RepositoryID>
            <Availability>Online</Availability>
            <AccessRights>Open</AccessRights>
            <AccessURL>
                <URL>http://amda.cdpp.eu</URL>
            </AccessURL>

            <Format>Text</Format>
            <Acknowledgement> AMDA is a science analysis system provided by the Centre de Donnees de la 
            Physique des Plasmas (CDPP) supported by CNRS, CNES, Observatoire de Paris and 
            Universite Paul Sabatier, Toulouse           
         </Acknowledgement>

        </AccessInformation>
        <ProviderName>IRAP</ProviderName>
        <InstrumentID>spase://CDPP/Instrument/AMDA/MEX/ELS</InstrumentID>

        <MeasurementType>ThermalPlasma</MeasurementType>

        <TemporalDescription>
            <TimeSpan>

                <StartDate>2003-06-23T18:42:48Z</StartDate>

                <StopDate>2018-09-05T09:21:05Z</StopDate>

            </TimeSpan>

            <Cadence_Min>PT1S</Cadence_Min>

            <Cadence_Max>PT64S</Cadence_Max>

        </TemporalDescription>
        <ObservedRegion>Mars</ObservedRegion>

        <Caveats><!--                                                                                                                                                                                                                        
   * Concerning ELS NEV Data :Before 2003/190 (09 July 2003), operational engineering tests were being executed on the ELS instrument.  Before 2100 hours on that date,        

the ELS science data should be all zero (except for day 2003/183,             
02 July 2003, between 0100 hours and 0200 hours).  For all times other        
than the 2003/183 (2003-07-02) time listed above, ELS was undergoing the      
Near Earth Verification tests.  These tests adjusted the ELS instrument       
voltages and the ELS science data was monitored to be sure that the           
science data were all zero.  If ELS science data had not been zero, it        
would have been an indication that there was something wrong with the         
instrument.  Thus, the zeroes in the ELS science data are normal and          
expected during these times.                                                  

The exception for day 2003/183 (02 July 2003) between 0100 hours and 0200 hours was when the deflection plates were not stepping and the           
instrument voltages were increased such that a science signal could be seen.  Since the ELS was not sweeping but held at a fixed value, there        
should be science data only at one energy (although the numeric value for     
each sector should be different).  Science data values should show in all     
sectors of ELS, not just in sector zero.  Tests were to include sweeping      
of the deflection plates at this time, but a small bug in the operations      
software prevented sweeping.  This was not fixed until after 2100 hours       
on day 2003/190 (09 July 2003).                                               
                                                                              
                                                                              

 * Concerning ELS January 2004 Data: The Mars Express commissioning period for ASPERA-3 occurred in January 2004. Since operational engineering tests were being executed on the ELS instrument during this time, some of the ELS science data are all zeroes.  The zeroes are normal and expected during January 5, 12, and 14, 2004.  If the ELS science data had not been zero during these times, it would have been an indication that there was something wrong with the instrument.                                                    

 * Note on Noise Levels: The ELS sectors which view across the spacecraft and into the spacecraft   

body measure electrons escaping the spacecraft either due to outgassing by    
the spacecraft, emissions from the spacecraft surfaces, scattered primary     
electrons reflected from the spacecraft, or secondary electrons that had      
been absorbed and then re-emitted by the spacecraft.  From launch until       
about mid-2004, spacecraft outgassing is observed as an increase in the       
background values to higher than normal levels in those sectors which view    
across the spacecraft.                                                        
   These background levels of each sector are known to vary in time.  This    
is caused when some ELS sectors view across the spacecraft or at spacecraft   
objects.  In launch configuration, ELS sectors 15, 14, 13, 12, 1, and 0       
view over the spacecraft.  In addition ELS sector 1 includes a spacecraft     
sun sensor within its field of view, and ELS sector 13 views the spacecraft   
solar array attachment arm.  The ELS was in its launch configuration until    
January 24, 2006 when the scanner platform was activated.  After this date,   
the angle which the scanner is rotated determines the degree of blockage by   
the spacecraft for each sector.                                               
   The scanner angle is set at 90 deg for the launch configuration (this is   
0 deg in the Unit Reference Frame).  When the scanner rotates, it moves       
toward the 0 deg position (+90 deg in the Unit Reference Frame).  At this     
time, ELS sectors 15, 14, 13, and part of sector 12 rotate to view the        
spacecraft body.  ELS sector 0 and 12 view across the spacecraft.  The        
scanner then rotates toward its 180 deg position (-90 deg in the Unit         
Reference Frame) when active.  As the scanner rotation passes the 90 deg      
position, ELS sectors 0, 1, 2, and part of sector 3 view the spacecraft       
body.  ELS sector 15 and 3 view across the spacecraft.                        
   It should also be noted that the relative calibration factors (relative    
efficiency coefficients for Anode 13 in CALINFO.TXT) indicate that the        
sensitivity of sector 13 is lower than the rest of the sectors by a factor    
of about 2 or 3.  A rough estimate of the orientation of the particle         
entrance geometry to the MCP indicated that the electrons in this sector      
penetrate deeper into the MCP chevron than the other sectors.  This means     
that there are fewer electrons generated by the MCP during the cascade        
(electron multiplication) process.  Thus, this intensity difference has       
been compensated for by the relative calibration factors for this sector.     
                                                                              
                                                                              

 * Note on Artificial Peaks in Spectra:  At about 150 eV, there is an artificial effect which is caused by the      

transition between control states of the ELS power supplies.  This            
artificial effect appears as a peak, drifting in amplitude, shape, and        
affected energy range.  The artificial peak occurs because the controlling    
signal to ELS exceeds its designed specifications and exhibits enough         
drift so that the controlling voltage sent to ELS does not accurately         
reflect the control voltage reported by the ASPERA-3 Main Unit.  This         
results in an error in the measurement energy which occurs at the lowest      
control voltage (where the drift is a larger part of the control signal).     
The flux measured at the expected energy is actually measured at a lower      
energy than expected (where the flux is slightly higher).  The region         
affected by the artificial spike at about 150 eV rarely exceeds 200 eV.       
   The ELS stepping power supply has two ranges.  The stepping voltage        
value is controlled by an analog signal sent to ELS by the ASPERA-3 Main      
Unit. The power supply range is controlled by a digital bit. ELS converts     
the analog control voltage into a voltage across its deflection plates        
which relates to the particle energy.  Thus, an error in the control          
voltage translates into an error in the particle energy.                      
   ELS has a voltage monitor that reports every sample, but it is accessed    
by the ASPERA-3 main unit only about every 32 sec.  ELS was to use the        
monitor value along with the science data value to correct for any drift      
within the sweep voltage.  Unfortunately due to telemetry restrictions,       
a decision was made to not telemeter the step voltage monitor the same        
time as the science data, so no correction can be determined between the      
voltage monitor drift and the energy shift observed in the science data.      
   This same effect is likely to be hidden in the low range deflection,       
below about 10 eV.  Its existence and magnitude can not be accurately         
assessed because the ASPERA-3 main unit does not sample the simultaneous      
sweep, monitor, and science data for ELS.  An artificial spike is noticed     
at about 150 eV because any drift in the control voltage is a larger          
fraction on the low voltage side of the high range and a smaller fractional   
fluctuation on the higher voltage side of the low range.  The ELS sweep is    
a decay step from its highest voltage value to its lowest voltage.  The       
spike is seen by the observer because it is highlighted by the transition     
between the sweep high range (larger fractional error) to the low range       

(smaller fractional error).   -->Data gap 2015-05-24 - 2015-07-01</Caveats>

        <Parameter>

            <Name>counts : per anode ##anode##</Name>

            <ParameterKey>mex_els_spec</ParameterKey>

            <Description>energy spectrogram of electron counts</Description>

            <Ucd>phys.count;phys.electron</Ucd>

            <Units>cnts</Units>

            <RenderingHints>
                <DisplayType>Spectrogram</DisplayType>
            </RenderingHints>

            <Structure>
                <Size>128</Size>
            </Structure>

            <Particle>
                <ParticleType>Electron</ParticleType>
                <ParticleQuantity>Counts</ParticleQuantity>
            </Particle>
        </Parameter>

        <Parameter>
            <Name>counts : sum over anodes</Name>
            <ParameterKey>mex_els_spec_sum</ParameterKey>
            <Description>energy spectrogram of electron counts</Description>
            <Ucd>phys.count;phys.electron</Ucd>
            <Units>cnts</Units>
            <RenderingHints>
                <DisplayType>Spectrogram</DisplayType>
            </RenderingHints>
            <Structure>
                <Size>128</Size>
            </Structure>
            <Particle>
                <ParticleType>Electron</ParticleType>
                <ParticleQuantity>Counts</ParticleQuantity>
            </Particle>
        </Parameter>

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