2.2.6 spase://CDPP/NumericalData/AMDA/Rosetta/LAP/ros-lap-efl e-field component (EFL) Electric field component, calculated on ground by taking the difference between floating probe measurements on both probes and dividing by distance 2016-10-15T14:08:29Z The two LAP probes could be used to measure the component of the electric field along their separation vector, by measuring the voltage of them, taking the difference and dividing by the separation distance (5.0 m). Each probe could be fed by a bias current as is typically done on electric field instruments in tenuous plasmas, or be disconnected from the bias circuitry to ensure a good zero bias current (floating probes) as is typically done on sounding rockets. Bias currents were used in the early part of the mission, but when the comet ionosphere developed, the floating mode was found to give much more consistent data. Only data from the floating mode have been used for providing E-field data, and only when both probes are sunlit. Positive value refers to electric field pointing in the direction from probe 1 to probe 2. The booms are not equal in length (2.24 and 1.62 m) and mounted on a big spacecraft (solar panel wingspan 32 m), so one cannot expect LAP to provide a useful DC electric field estimate. A moving average of the E-field over 32 s is therefore subtracted from the data in the EFL files. The effective bandwidth of the data therefore is about 0.03 Hz to 20 Hz, the upper limit set by the analog anti-aliasing filters. Note that the filtering may distort the lowest frequencies. There are no external comparison data for assessing the absolute accuracy of the LAP E-field measurements. The data themselves look very clean and well behaved [Karlsson et al., 2017; André et al, 2017], with very little of common mode signal remaining, despite the s/c poten tial being both high and highly variable. The technique with floating probes is proven on numerous sounding rockets in the terrestrial ionosphere [Maynard, 1998]. spase://CDPP/Person/Anders.Eriksson PrincipalInvestigator spase://CDPP/Person/Erik.Johansson DataProducer RPC LAP User Guide http://amda.irap.omp.eu/help/parameters/RO-IRFU-LAP-UG.PDF ROSETTA RPC-LAP to Planetary Science Archive Interface Control Document http://amda.irap.omp.eu/help/parameters/RO-IRFU-LAP-EAICD_2_0_1_PDF_A.PDF spase://SMWG/Repository/CDPP/AMDA Online Restricted http://amda.cdpp.eu NetCDF PSA RO-C-RPCLAP-5-xxx-DERIV2-V1.0 spase://CDPP/Instrument/AMDA/Rosetta/LAP ThermalPlasma 2014-03-24T08:12:59Z 2016-09-30T10:31:16Z PT0.05S PT35S e-field comp ros_lap_efl Electric field component, calculated on ground by taking the difference between floating probe measurements on both probes and dividing by distance, (V_P2-V_P1)/L. Positive value refers to electric field pointing in the direction from probe 1 to probe 2. mV/m TimeSeries -1.e+09 sampling conf ros_lap_efl_s Number that describes the exact combination of onboard s/w averaging and downsampling. The exact values are pointers into a table that describes both the number of samples that are averaged over and the downsampling rate TimeSeries quality flag ros_lap_efl_f 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). TimeSeries