CDPP / CNES

Commit ad7a238ed66bacf987214308c9abfff2b4262d17

Authored by Elena.Budnik
1 parent 303f2ca9
Exists in master and in 12 other branches amdadev, aschulz, autocommit, bepi_master, bepi_update, branch_q, cleanup_registry, cleanup_registry_master, cleanup_registry_merged, juice_jdc, juno_jade, soar

small cor in LAP EFL

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NumericalData/AMDA/Rosetta/LAP/ros-lap-efl.xml
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7 7 <ResourceName>e-field component (EFL)</ResourceName>
8 8 <AlternateName>Electric field component, calculated on ground by
9 9 taking the difference between floating probe measurements on both probes and
10   -dividing by distance, (V_P2-V_P1)/L. Positive value refers to electric field
11   -pointing in the direction from probe 1 to probe 2.</AlternateName>
  10 +dividing by distance</AlternateName>
12 11 <ReleaseDate>2016-10-15T14:08:29Z</ReleaseDate>
13 12 <Description>
14 13 The two LAP probes could be used to measure the component of the electric field along their
15 14 separation vector, by measuring the voltage of them, taking the difference and dividing by the
16 15 separation distance (5.0 m). Each probe could be fed by a bias current as is typically done on
17 16 electric field instruments in tenuous plasmas, or be disconnected from the bias circuitry to
18   -ensure a good zero bias current (floating probes) as is typically done on sounding rockets.
  17 +ensure a good zero bias current (floating probes) as is typically done on sounding rockets.
19 18 Bias currents were used in the early part of the mission, but when the comet ionosphere
20   -developed, the floating mode was found to give much more consistent data. Only data from
  19 +developed, the floating mode was found to give much more consistent data. Only data from
21 20 the floating mode have been used for providing E-field data, and only when both probes are
22 21 sunlit.
23 22  
  23 +Positive value refers to electric field pointing in the direction from probe 1 to probe 2.
  24 +
24 25 The booms are not equal in length (2.24 and 1.62 m) and mounted on a big spacecraft (solar
25 26 panel wingspan 32 m), so one cannot expect LAP to provide a useful DC electric field estimate.
26 27 A moving average of the E-field over 32 s is therefore subtracted from the data in the EFL files.
27   -The effective bandwidth of the data therefore is about 0.03 Hz to 20 Hz, the upper
28   -limit set by the analog anti-aliasing filters. Note that the filtering may distort the lowest
  28 +The effective bandwidth of the data therefore is about 0.03 Hz to 20 Hz, the upper
  29 +limit set by the analog anti-aliasing filters. Note that the filtering may distort the lowest
29 30 frequencies.
30 31  
31 32 There are no external comparison data for assessing the absolute accuracy of the LAP E-field
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