Version:2.4.1
NumericalData
ResourceID
spase://CNES/NumericalData/CDPP-AMDA/Rosetta/LAP/ros-lap-usc
ResourceHeader
ResourceName
Rosetta - LAP - s/c potential (USC)
AlternateName
Spacecraft potential
ReleaseDate
2019-08-27 10:05:12Z
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.
Contacts
InformationURL
InformationURL
Name
RPC LAP User Guide
URL
InformationURL
Name
RPC-LAP to Planetary Science Archive Interface Control Document
URL
InformationURL
Name
RPC-LAP Report on cross-calibration of LAP data to measurements by other RPC instruments
URL
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
CDPP/AMDA HAPI Server
URL
Style
HAPI
ProductKey
ros-lap-usc
Description
Web Service to this product using the HAPI interface.
Format
CSV
Acknowledgement
Thank you for acknowledging the use of AMDA in publications with wording like "Data analysis was performed with the AMDA science analysis system provided by the Centre de Données de la Physique des Plasmas (CDPP) supported by CNRS, CNES, Observatoire de Paris and Université Paul Sabatier, Toulouse". See the Rules of the road at https://amda.cdpp.eu/help/policy.html . Please acknowledge the Data Providers.
AccessInformation
RepositoryID
Availability
Online
AccessRights
Open
AccessURL
Name
CDPP/AMDA Web application
URL
Description
Access to Data via CDPP/AMDA Web application.
Format
CSV
Format
VOTable
Format
CDF
Format
PNG
Acknowledgement
Thank you for acknowledging the use of AMDA in publications with wording like "Data analysis was performed with the AMDA science analysis system provided by the Centre de Données de la Physique des Plasmas (CDPP) supported by CNRS, CNES, Observatoire de Paris and Université Paul Sabatier, Toulouse". See the Rules of the road at https://amda.cdpp.eu/help/policy.html . Please acknowledge the Data Providers.
ProviderName
PSA
ProviderResourceName
RO-C-RPCLAP-5-xxx-DERIV2-V1.0
InstrumentIDs
MeasurementType
ThermalPlasma
TemporalDescription
TimeSpan
StartDate
2014-03-24 15:21:18Z
StopDate
2016-09-30 10:36:32Z
CadenceMin
PT32S
CadenceMax
PT160S
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.
Parameter #1
Name
u_sc
ParameterKey
ros_lap_usc
Units
V
RenderingHints
Support
Parameter #2
Name
u_sc : qual
ParameterKey
ros_lap_usc_q
Description
Quality value in the range 0 (worst) to 1 (best).
Corresponds to goodness of fit or how well the model fits the data.
RenderingHints
Support
Parameter #3
Name
data source
ParameterKey
ros_lap_usc_s
RenderingHints
Support
Parameter #4
Name
quality flag
ParameterKey
ros_lap_usc_f
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)
RenderingHints
Support
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