spase://CNES/NumericalData/CDPP-AMDA/Rosetta/LAP/ros-lap-usc

        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.

PSA

RO-C-RPCLAP-5-xxx-DERIV2-V1.0

ThermalPlasma

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.