PDS_VERSION_ID = PDS3                                                         
RECORD_TYPE    = STREAM                                                       
OBJECT         = TEXT                                                         
  PUBLICATION_DATE = 2003-09-19                                               
  NOTE             = "INFO.TXT describes the Electron Reflectometer (ER)      
                      3D electron energy spectrum data available on this      
                      volume."                                                
END_OBJECT    = TEXT                                                          
END                                                                           
                                                                              
The DATA/ER_3DIST directory contains the Electron Reflectometer (ER)          
3D electron energy spectrum data. These files reside in subdirectories        
containing data from single months; the names of these subdirectories         
indicate the month and year of the data (for example, JAN_1998). The file     
naming convention for files in the one-month subdirectories of the            
DATA/ER_3DIST directory is as follows:                                        
                                                                              
3D980116.TAB is interpreted as                                                
                                                                              
3D  = '3D electron energy spectrum data'                                      
98  = year 1998                                                               
01  = first month (January)                                                   
16  = sixteenth day of month                                                  
TAB = 'table' format                                                          
                                                                              
3D980116.LBL is the name of the PDS label file which describes the data       
file 3D980116.TAB.                                                            
                                                                              
The 3D data are provided as ASCII tables of 1 day duration.  The table        
contains data sampled over 16 spacecraft spins, with a full 3D spectrum       
produced as the detector spins and steps.  A record in the table              
consists of the following elements:  a time tag in PDS format,                
pertaining to a single record; a time tag in seconds since epoch 1970,        
pertaining to an entire spectrum made up of 15 records; the energy bin        
for the record; the spectrum number for the spectrum (starting with 1 at      
the beginning of the file); 3 magnetic field components; and then a           
structure of 88 flux values and 88 phi values.                                
                                                                              
The DATA/ER_3DIST directory also contains a file THETA.TAB, which is an       
ASCII table containing 88 values of the inclination angle that the            
detector center makes with the spacecraft spin, corresponding to the 88       
phi values in the data. The file THETA.LBL is the detached PDS label for      
THETA.TAB.                                                                    
                                                                              
In addition to the data files, 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, and are described in       
the files CATALOG/CATINFO.TXT and DOCUMENT/DOCINFO.TXT. Of particular         
interest to users of the ER 3D data is the ER 3D dataset catalog file,        
CATALOG/ER3D_DS.CAT.                                                          
                                                                              
This disk also contains 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.                            
                                                                              
In addition to accessing the ER 3D data files directly, users with            
Web browsers can access them via links in the HTML file ER3DDATA.HTM          
in the EXTRAS directory, and can navigate the entire disk using the file      
AAREADME.HTM in the disk root directory.