History (Part 1) of HF propagation models by Ray Rosich, 1978
[This document is part of the help files integrated into the ITS HFBC software package.]
This information was extracted from an ancient informal letter from Ray Rosich dated June 8, 1978. It has been included here as an item of historical significance. Remember, any reference to "latest" means as of June 1978.
Lenora, June 8, 1978
For your future information and use, the history of the HF Ionospheric
Radio Propagation Models developed at ITS is as follows:
* late 1930's and during World War II, a lot of research on propagation
and the characteristics of the ionosphere was done.
* 1945: the Radio Propagation Unit of the U.S.Army Signal Corps published
a report (Kelley, L., Tech. Report No.6, 1945) which summed
up their knowledge to that point.
* 1948: CRPL published a treatise on ionospheric radio propagation
(NBS Circular 462) which outlined the current state of the art
in HF propagation and prediction (manual) methods.
* 1950: Laitinen and Haydon (Tech. Report 9, U.S. Army Signal Radio
Propagation Agency) presented a quite complete manual method based
upon theoretical and empirical techniques.
* The above techniques and other to this time were very laborious and
time consuming, and to alleviate this problem various workers began
to think of computerizing the techniques that existed.
* 1957: Stanford Research Institute (Special Report 1) offered such a program.
* 1961: Lucas and Haydon (NBS Report 6789) presented the first of a number of
techniques (computerized) developed by them. This one was based upon
computerization of the manual methods used up to that time.
* (MUFFOT): Techniques developed to make use of the full power of
the computer (as opposed to manual techniques) were to come later.
These techniques were made possible by the numerical maps of the
ionospheric characteristics (computerized) developed by Roger Gallet,
Bill Jones, Margo Leftin/Pokempner, Frank Stewart, Ron Graham, and
others in CRPL at that time.
* 1962: (MUFLUF): Lucas and Haydon (NBS Report 7619) utilized the most
recent of the computerized maps and techniques available to develop
a computer program to estimate the performance of HF communication
(ionospheric) systems.
* 1966: (ITSA1): Lucas and Haydon (ESSA Tech. Report IER 1-ITSA 1) developed
the first truly complete computerizated HF ionospheric propagation
prediction program. This is the model that is referred to as the
ITSA1 program, but actually it existed in a number of versions with
different names, such as, SEPARTI, GEELOB, ALLMODES, etc.
*(RADARC): When Lucas left ITSA in late-1966/early-1967, the model
first being worked on by him from then on for a while was called
CHIEFY. Later verious Radar versions were developed by Lucas, Lloyd,
Headrick, Thomason, and others (NRL Memo Report 2500, 1972), and
called RADARC, RAMHF, and other such names. These developments all
culminate in various Radar versions of their propagation model which
provide the core of ideas behind the IONCAP model described below.
*(ITS78): Following a separate path than Lucas, et. al., starting from the
ITSA-1 model, Barghausen and his group at ITSA developed a
communication (point-to-point rather than radar) model (ESSA Tech.
Report ERL 110-ITS 78) known as the ITS78 model. There were several
models and computer programs chronologically as the model and
program were improved. Each program was given a slightly different
name and was also color coded (Red Deck, Blue Deck, Yellow Deck, etc.)
according to the color of the cards on which it was sent out. The
color coding was done in an effort to make it simple to determine
which version that a given person or organization had when they called
on the phone to ask questions. This did not always work, however, as
they would often keep the deck that we sent as a "master deck" not to
be touched. They would duplicate the deck on their own cards and then
work on this secondary deck - and in the process loose the color code!
Later (with HFMUFES 3 - the Yellow Deck) we began to have the program
print out at the top of every page the program name and the version
number and the date of that version. In this fashion we could find
out which version the person had, as all he had to do was look at his
computer printout.
The deck names, color codes, and significant characteristics of
the programs are as follows:
Program Name Color Significant Characteristics
------------ ------ -------------------------------------------------
HFMUFES Red The program as originally listed in Appendix A
(pages 160-224) of the ESSA Tech. Report
ERL 110-ITS 78.
HF = High Frequency
MUF= Maximum Useable Frequency
ES = Sporadic E
First and original version of the ITS 78 program.
HFMUFES2 Blue This version had a number of bugs fixed over
HFMUFES, and a number of improvements added. In
particular the "2" in the program name indicates
that the continuous (on month and SSN) maps of
foF2 were added. The atmospheric noise maps and
ground conductivity/dielectric constant maps were
also revised per reports OT/ITSRR 2 & OT/TRER 31.
Multiple antennas at the transmitter and receiver
(up to 3 each) were allowed. Revised virtual
height maps for the bottom of the F-layer and the
E-layer critical frequency (foE) were included.
A number of other changes were also made - all
described in the "form" cover letter to the
Blue Deck (part of the Errata and Addenda).
HFMUFES3 Yellow A number of bugs were found in HFMUFES2 & fixed.
In addition the program was modified to allow
antenna patterns to be read in, an error in
subroutine RELBIL was fixed, the "curtain"
antenna was modified to allow in-phase and
anti-phase configurations. The foEs deciles and
median were checked to insure correctness,
subroutine WOMAP was fixed, the ground reflection
point calculation & loss calculation were fixed.
AND EXTENSIVE COMMENT CARDS WERE ADDED TO THE
PROGRAM to explain what the program was doing
and to provide references to the reports and
books where the equations, etc. were obtained.
Also a revised version was installed on the
Univac 1108 in Washington,D.C. for use by
OT/IRAC. This is documented in an unpublished
report by R.K. Rosich, R.G. Peterson,
L.L. Proctor, The OT/ITS-IRAC HF Ionospheric
Propagation Prediction Program.
HFMUFES4 None. This is the current latest version of the program
sent on as sent out by Vaughn Agy. A number of fixes &
magnetic improvements were made by myself, Margo Leftin/
tape Pokempner, and Vaughn Agy. The program is
documented (like HFMUFES3) in terms of report
ITS 78 and copious comment cards in the program,
but also in OT Report 76-102 by Haydon, Leftin,
and Rosich. This version runs on CDC-6600
computer, whereas the others ran on the CDC-3800
computer. It is written entirely in FORTRAN and
occupies roughly 500K to 600K bytes of memory,
and the data base occupies roughly 2.4MBytes
on either disc or magnetic tape.
IONCAP None. This is the latest version of the program being
developed by John L. Lloyd and Larry R. Teters.
It is highly modularized, written entirely in
ANSI FORTRAN, and occupies about the same number
of bytes of memory and data base. It is expected
to be released soon to replace HFMUFES4 and will
come with 4 volumes of documentation:
Vol 1: Mathematics & Physics of the Model
Vol 2: Internal Structure of the Program
Vol 3: User's Manual giving details of the
mechanics of the user of the program
Vol 4: An annotated listing of the program.
As noted earlier, this program is based upon the
good points of both HFMUFES4 and upon the
modeling developments of RADARC.
I hope that this helps once and for all to completely spell out the history and existence of
the various HF Ionospheric Propagation Models that have been developed by ITS personnel.
It should also serve to identify which computer programs and reports are associated with each
of these modeling efforts. If there are any further questions, please do not hesitate to ask them.
Ray Rosich