LP ER 3-D Electron Flux Data (ER_3D, Level 1B)
ER_3D – LP ER 3-D Electron Flux Data Collection, Level 1B
Instrument: Electron Reflectometer
PDS3 Data Set ID: LP-L-ER-3-RDR-3DELEFLUX-80SEC-V1.0DOI: 10.17189/1519719
PDS4 Collection: urn:nasa:pds:lp-er-calibrated:data-3delefluxDOI: 10.17189/ze5j-k897
For more information about ER_3D products, see the Lunar Prospector ER 3-D Electron Flux Data Description.
The Lunar Prospector Electron Reflectometer (LP-ER) Level 1B Omni-directional 3D Electron Flux Data (ER_3D) data products are a time ordered series of 3D spectrum electron measurements. Each record consists of a time tag with an 88x15 array of scalar data points representing measurements of the electron flux in 88 solid angles covering 4pi steradians and 15 energy channels logarithmically spaced from 10 eV to 20 keV, with an energy resolution (dE/E) of 25%. Each data point is a measure of the electron flux (cm-2s-1ster-1eV-1) within one of the 88 approximately equal-sized solid angles.
Angles are given in despun spacecraft (SCD) coordinates, in which the Z-axis coincides with the spacecraft spin vector, and the direction of the sun is in the half plane defined by X > 0, Y = 0. These data records are accumulated during ½ spin of the spacecraft (~2.5 seconds) and sampled every 16 spins (~80 seconds). For convenience, the average magnetic field vector during the ~2.5 second accumulation time is provided to facilitate calculation of electron pitch angle distributions from the 3D data.
Each of the 88 solid angle bins are approximately the same size. The exact sizes are given below.
|
Latitude Range (degrees) |
Number of Longitude Bins |
Solid Angle Bin Size (ster) |
|
67.5 to 90.0 |
4 |
0.119570 |
|
45.0 to 67.5 |
8 |
0.170253 |
|
22.5 to 45.0 |
16 |
0.127401 |
|
0.0 to 22.5 |
16 |
0.150279 |
|
0.0 to -22.5 |
16 |
0.150279 |
|
-22.5 to -45.0 |
16 |
0.127401 |
|
-45.0 to -67.5 |
8 |
0.170253 |
|
-67.5 to -90.0 |
4 |
0.119570 |
ER_3D products have the following file names:
3Dyymmdd.TAB (with detached PDS label)
where:
yy = year of data collection
mm = month of data collection
dd = day of data collection
Additionally, there are 2 ancillary files in this dataset. Theta.tab, with its corresponding label file, gives the polar angle of the detector as it steps within each spectrum. These values do not change with time. Outages.tab, with its corresponding label file, lists times and information about data gaps our outages in Lunar Prospector merged telemetry files for the entire LP mission.
In ODE, ER_3D products have the following product IDs:
3DYYMMDD
THETA.TAB
OUTAGES