<?xml version="1.0" encoding="UTF-8"?>

<Spase xmlns="http://www.spase-group.org/data/schema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.spase-group.org/data/schema http://amda.irap.omp.eu/public/schemas/spase-2_3_1.xsd">

    <Version>2.3.1</Version>
    <NumericalData>
        <ResourceID>spase://CNES/NumericalData/CDPP-AMDA/Rosetta/LAP/ros-lap-usc</ResourceID>
        <ResourceHeader>
            <ResourceName>s/c potential (USC)</ResourceName>
            <AlternateName>Spacecraft potential</AlternateName>
            <ReleaseDate>2016-10-15T14:08:29Z</ReleaseDate>
            <Description>For most science purposes, the most useful s/c potential estimate is the U_SC data product 
            which is available at 32 to 160 second resolution and covers 
            most of the mission. 
            
            Depending on instrument operational mode, this is taken either from the  
            average over 32 s of measured voltage of a sunlit LAP probe (preferably LAP1) floating with 
            no bias current or voltage applied, sometimes known as Vfloat, or by the equivalent estimate from Langmuir  
            probe bias sweeps, which the voltage Vz at which the current to the probe is 
            zero. We expect U_SC to  differ from the true spacecraft potential 
            by a small offset (due to the potential over the probe sheath, of order one volt) and a factor 
            (typically 75-80%) due to some part of the potential field from the spacecraft remaining at the 
            probe position.
            
            A parameter DATA_SOURCE indicates which of these methods have been 
            used for every single sweep.
            
This is a preliminary data set which will be replaced by another in a few months.            
            </Description>
            <Contact>       
                <PersonID>spase://CNES/Person/Anders.Eriksson</PersonID>
                <Role>PrincipalInvestigator</Role>
            </Contact>
            <Contact>       
                <PersonID>spase://CNES/Person/Erik.Johansson</PersonID>
                <Role>DataProducer</Role>
            </Contact>
            <InformationURL>
                <Name>RPC User Guide</Name>
                <URL>http://amda.irap.omp.eu/help/parameters/RPC_USER_GUIDE.PDF</URL>
            </InformationURL>
            <InformationURL>                
                <Name>RPC LAP User Guide</Name>
                <URL>http://amda.irap.omp.eu/help/parameters/RO-IRFU-LAP-UG.PDF</URL>
            </InformationURL>
            <InformationURL>
                <Name>RPC-LAP to Planetary Science Archive Interface Control Document</Name>
                <URL>http://amda.irap.omp.eu/help/parameters/RO-IRFU-LAP-EAICD.PDF</URL>
            </InformationURL>
            <InformationURL>
                <Name>RPC-LAP Report on cross-calibration of LAP data to measurements by other RPC instruments</Name>
                <URL>http://amda.irap.omp.eu/help/parameters/RO-IRFU-LAP-XCAL.PDF</URL>
            </InformationURL>               
        </ResourceHeader>
        <AccessInformation>

            <RepositoryID>spase://SMWG/Repository/CNES/CDPP-AMDA</RepositoryID>

            <Availability>Online</Availability>
            <AccessRights>Restricted</AccessRights>
            <AccessURL>
                <URL>http://amda.cdpp.eu</URL>
            </AccessURL>
            <Format>NetCDF</Format>
        </AccessInformation>
        <ProviderName>PSA</ProviderName>  
        <ProviderResourceName>RO-C-RPCLAP-5-xxx-DERIV2-V1.0</ProviderResourceName>

        <InstrumentID>spase://CNES/Instrument/CDPP-AMDA/Rosetta/LAP</InstrumentID>

        <MeasurementType>ThermalPlasma</MeasurementType>
        <TemporalDescription>
            <TimeSpan>
                <StartDate>2014-03-24T08:12:59Z</StartDate>
                <StopDate>2016-09-30T10:31:16Z</StopDate>
            </TimeSpan>
            <CadenceMin>PT32S</CadenceMin>

            <CadenceMax>PT160S</CadenceMax>

        </TemporalDescription>
        <Caveats>Data Source :
            * 1 - Downsampled floating potential measurement for an illuminated LAP1
            * 2 - Downsampled floating potential measurement for an illuminated LAP2
            * 3 - Vz for LAP1
            * 4 - Vz for LAP1, but using a linearly extrapolated sweep
            
            Quality Flag : 
            
A quality flag is a (base 10) integer that is constructed in the two steps below:
* Add together the constants associated with the relevant quality-related effects listed below. Note that these constants are chosen such that every digit represents up to three true/false values for the presence/absence of three specific separate quality-related effects.
* Should the three quality-related effects be irrelevant for the given data product, then that digit is replaced by the digit “9”.

Quality flag event description :
* +1 - Low quality sweep analysis model fit
* +2 - One of two meanings: (1) Low sample size; an average is based on fewer data points than nominal (due to filtering or otherwise) and applies to sweep steps and downsampled time series. (2) zero-padding; zeros replace lost samples for the purpose of calculating PSD.
* +10 - One of two meanings: (1) Sweep data product and data products based on sweeps: SAA rotation of more than 0.05° during sweep. (2) Downsampled time series data product: Bias change within the 32 s downsampling period.
* +20 - Probe in partial or full shadow
* +100 - Rosetta wheel off-loading (WOL) or Orbit-control-maneuver (OCM)
* +200 - One of two meanings: (1) For LAP1: LDL disturbance (LAP2 in LDL mode); (2) For LAP2: Contamination signature possibly present
* +400 - Saturation

Example: suppose that one encounters the quality flag “109”. 109 = 100 + 9 means (1) that there is an ongoing wheel off-loading (+100), and (2) that the quality-related effects associated with +1 and +2 cannot occur even in principle for the kind of data that one is looking at.           
         </Caveats>
        <Parameter>
            <Name>u_sc</Name>
            <ParameterKey>ros_lap_usc</ParameterKey>
            <Ucd/>
            <Units>V</Units>
            <RenderingHints>
                <DisplayType>TimeSeries</DisplayType>
            </RenderingHints>
            <FillValue/>
        </Parameter> 
        <Parameter>
            <Name>u_sc : qual</Name>
            <ParameterKey>ros_lap_usc_q</ParameterKey>
            <Description>Quality value in the range 0 (worst) to 1 (best). 
Corresponds to goodness of fit or how well the model fits the data.</Description>
            <Ucd/>
            <Units/>             
            <RenderingHints>
                <DisplayType>TimeSeries</DisplayType>
            </RenderingHints>
            <FillValue/>
        </Parameter> 
        <Parameter>
            <Name>data source</Name>
            <ParameterKey>ros_lap_usc_s</ParameterKey>
            <Ucd/>
            <Units/>         
            <RenderingHints>
                <DisplayType>TimeSeries</DisplayType>
            </RenderingHints> 
             <FillValue/>
        </Parameter>
        <Parameter>
            <Name>quality flag</Name>
            <ParameterKey>ros_lap_usc_f</ParameterKey>
            <Description>Quality flag constructed as the sum of multiple terms, 
depending on what quality related effects are present. Each digit is either in 
the range 0 (best) to 7 (worst), or 9 (not used)</Description>
            <Ucd/>
            <Units/>         
            <RenderingHints>
                <DisplayType>TimeSeries</DisplayType>
            </RenderingHints> 
             <FillValue></FillValue>
        </Parameter>            
     </NumericalData>
</Spase>