*** DISTRIBUTION NOTICE ***
This file and the data set it describes are UNCLASSIFIED and may be
distributed on unrestricted electronic systems (e.g., a web page or
anonymous FTP).
*** DISTRIBUTION NOTICE ***

README File - HEO Data Distribution Text Files

This file introduces the documentation for the HEO data
archive. First, there is a brief introduction to the HEO data set,
followed by a table of contents for the other documentation files.

Introduction to HEO

The HEO acronym indicates satellites in Highly Elliptical Orbit, also
known as Molniya orbits. These orbits have period of roughly 12 hours,
with a perigee of no more than a few hundred kilometers, apogee of
roughly 7 Re, and an inclination of about 63 degrees.

At present, data from two HEO missions is available in this archive:
HEO 1 and HEO 3. These data consist of energetic particle
measurements, given as proton counts, electron counts, and dose/dose
rate. The spacecraft are equipped with a combination of dome and
telescope dosimeters. Data from these instruments is available in
15-second averages and binned by magnetic L shell in IGRF and
Olson-Pfitzer (Quiet) field models. (Data from HEO 2 have
not been processed to the level required for release).

The F1 and F3 dosimeters have Dose channels (D1, D2, D3, D4) and
corresponding Electron (E3, E4, E5, E6) and Proton (P4, P5, P6, P7)
channels.  F1, F2 and F3 also carry an electron-proton telescope to
measure lower energies. The telescopes provide two electron channels
(E1, E2) and three proton channels (P1, P2, P3, and, on HEO 3 only,
P4). Care should be taken with the telescope data. There is evidence
of a temperature dependent response in the data, especially in the P1
on F1, F2 and F3 and in P2 on F3. As the instruments and satellites
continue to age, the temperature will rise and other telescope
channels may show the temperature related "noise" response. Also, P4
on HEO 3 suffers from electron contamination.

In order that we may provide you with updates and revisions to the
data archive, please be sure that you provide Aerospace with your
contact information (email).

Aerospace Contacts

Data Distribution Project Manager:
     Joe Fennell (Joseph.F.Fennell@aero.org)
Data System Programmer:
     Mike Redding (Michael.T.Redding@aero.org)
Documentation Manager:
     Paul O'Brien (Paul.Obrien@aero.org)

Other Documentation

F1_Lbin.txt - Description of Lbin files for HEO 1 
F3_Lbin.txt - Description of Lbin files for HEO 3 
Glossary.txt - Definitions useful in using HEO data 
Dosimeters.htm - Table describing HEO dosimeters

This README file, other documentation provided with this data set, and
the data itself are provided by The Aerospace Corporation.

*** DISTRIBUTION NOTICE ***
This file and the data set it describes are UNCLASSIFIED and may be
distributed on unrestricted electronic systems (e.g., a web page or
anonymous FTP).
*** DISTRIBUTION NOTICE ***