Links To: Data | Browse Files | Documents | File Formats | File Naming (Data, Browse)
The Electron Reflectometer 3-D spectrum (ER 3D) data reside in the directory DATA/ER_3DIST. The data files are in subdirectories containing data from single months; the names of these subdirectories indicate the year and month (with month number and name) of the data. On this disk, the monthly subdirectories are 98_06JUN, 98_07JUL, 98_08AUG, 98_09SEP, and 98_10OCT.
The file naming convention for files in the one-month subdirectories of the DATA/ER_3DIST directory is illustrated by the following example. (The file mentioned here is only an example; there are many more such files on the disk.)
3D980601.TAB is interpreted as
3D = 'ER 3D data'
98 = year 1998
06 = month 06 (June)
01 = day 01 in month
TAB = 'table' format
3D980601.LBL is the name of the PDS label file which describes the data file 3D980601.TAB. Such label files provide descriptive information about the data files in a format which is both human-readable and machine-readable.
In addition to the ER 3D data files, the DATA/ER_3DIST directory contains a file THETA.TAB which gives the inclination angle (theta) for each detector step as the instrument cycles. There are 88 of these values, which are fixed throughout the instrument's operation. (The PDS label for THETA.TAB, which describes the table's format, is in THETA.LBL. See below for more on THETA.TAB.)
This disk also contains browse plots which summarize some of the ER data and other data.
This disk contains documentation files which describe the datasets on the disk, the instruments from which the data came, and the Lunar Prospector spacecraft and mission. These files are found in the CATALOG and DOCUMENT directories.
Of particular interest to users of ER 3D data are the following files.
In the CATALOG directory:
In the DOCUMENT directory:
The files on this disk are in level 1 compliance with the ISO 9660 standard. The disk contains data for 5 calendar months. The 3-D data are provided as ASCII tables of 1 day duration.
Each set of 16 consecutive rows contains data sampled over 16 spacecraft spins so that a full 3-D spectrum can be produced as the detector spins and steps.
The format of the data in the ER 3D files is described in the PDS labels (*.LBL files) accompanying the data. These label files are both human-readable and machine-readable.
THETA.TAB, which was mentioned in the Overview section of this document, is a ASCII table having one row and 88 columns. It contains 88 theta values, with one value corresponding to each of the 88 electron flux values.
In addition to the data files, this disk contains graphical browse plots, in GIF87A format, summarizing the Magnetometer (MAG) and Electron Reflectometer (ER) data on the disk. These plots are contained in the BROWSE directory.
Each browse file contains plots of the following items for a 12-hour period: electron count rate (at various energies); electron energy spectrum; magnetic field, as magnitude |B| and direction (phi, theta); polarity; and Sun sensor data. The data are plotted against two time scales (decimal day-of-year and hour-minute) and a scale of GSE longitude.
The naming convention for browse plots is illustrated by the following example. (The file mentioned here is only an example; there are many such files on the disk.)
9815212.GIF is interpreted as
98 = year 1998
152 = day of year 152 (where Jan. 1 = day of year 001)
12 = start time 1200 (in 24-hour time; 00 minutes is implied)
GIF = file in GIF format.
Return to end of Overview section
The following links can be used to navigate the ER 3D data files and browse files on this disk.
For information about the data format, see the File Formats section above and the *.LBL file accompanying each data file.
Links to data for: June 1998 | July 1998 | August 1998 | September 1998 | October 1998
