Besides this file, there are two *.txt files here that describe the contents of the RIMS moments dataset
and notes about how that data are calculated.  Further details can be found in 

Craven, P. D., D. L. Gallagher, and R. H. Comfort (1997), Relative concentration of He+ in the 
inner magnetosphere as observed by the DE 1 retarding ion mass spectrometer, J. Geophys. Res., 
102(A2), 2279-2289, doi:10.1029/96JA02176.

The text files are named:
empclt_data_format.txt
data_selection_and_fitting.txt

The C-code example read routine and the binary data to go with it are named:
sample_read_empclt.make
sample_read_empclt.c
empclt_merge.dat

The IDL code example and the data that goes with this are named:
run_read_xdr.pro
read_xdr.pro
empclt_merge_dat.xdr

The xdr format is machine independent and does not require IDL to read it.  Other languages are
include utilities for reading this format.