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Advances in Space Research 34 (2004) 1845-1850

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Karl Rawer's life and the history of IRI
Bodo W. Reinisch a,*, Dieter Bilitza b
a Department of Environmental Earth and Atmospheric Sciences, Center for Atmospheric Research, University of Massachusetts

Lowell, 600 Suffolk Street, Lowell, MA 01854, USA

b Raytheon ITSSISSD00, GSFC, Code 632, Greenbelt, MD 20771,

USA

Received 12 September 2004; accepted 13 September 2004

Abstract
This laudation is given in honor of the 90th birthday of Prof. Karl Rawer that coincides with the 35th anniversary of the International Reference Ionosphere (IRI). The ionosphere was discovered during Karl Rawer's life, and he has dedicated his life to the
exploration of this part of Earth's environment. The horrible events of world wars I and II shaped his early life, but they also
launched his career as one of the eminent geophysical scientists of the twentieth century. The paper looks back at Karl's life andthe 35 years of research and development in the framework of the IRI project. K. Rawer initiated this international modeling effort
and was the first chairman of the IRI Working Group. IRI is a joint project of the Committee on Space Research (COSPAR) andthe International Union of Radio science (URSI) that has the goal to establish an international standard model of the ionosphericdensities temperatures, and drifts.
© 2004 COSPAR. Published by Elsevier Ltd. All rights reserved.
Keywords: Karl Rawer; International Reference Ionosphere; Ionosphere

1. Introduction - Karl Rawer's early years"Actually, it was chance and circumstances that gaveme the opportunity to participate in the shaping of theresearch development in ionospheric and space scienceduring the 20th century" so reminisces Karl Rawer,
looking back on his life's achievements. From 1913 to
2003, i.e., from WW I to the current terrible war in Iraq,
Karl has seen the world change. He was fortunate tolearn from eminent physicists and mathematicians during his university years in the 1930s, Gustav Mie andGustav Dbtsch in Freiburg, and Arnold Sommerfeld
and Jonathan Zenneck in Mtinchen. Zenneck had
started ionospheric echo sounding experiments in Bavaria and asked Rawer to develop the theory for thereflection of vertically incident radio waves from the ion* Corresponding author. Tel.: +1 978 934 4903 fax: +1 978 459

7915.
E-mail address: BodoReinisch@uml.edu (B.W. Reinisch).

osphere as his doctoral thesis. Being allowed to use thejewel of the mathematics institute, an electrically driven
mechanical calculator, Karl was able to solve this problem in little more than a year. And from here on he washooked in one way or other to ionospheric research andthe computer, as an analysis tool, for the next 60 years.
During WW II, he became responsible for ionosphericradio predictions, working with Johannes Plendl andWalter Dieminger, and also Ewald Harnischmacher
and Klaus Bibl. When in 1945, after the end of thewar, Roy Piggott escorted Dieminger's Radiowave Research Team from its operational base in Austria to Lindau near G6ttingen (Niedersachsen) in the British
Occupation Zone, Rawer's group followed the invitation
by Yves Rocard to establish an ionospheric prediction
service in Germany's "French Zone". A new ionosphericinstitute came to life first in Neuershausen, then in Breisach (Baden-Wfirttemberg), i.e., close to Karl's academic origins in Freiburg and to his native Saarland.
One of the author (BWR) first met Prof. Rawer in

0273-1177/$30 @ 2004 COSPAR. Published by Elsevier Ltd. All rights reserved.
doi: 10.1016/j.asr.2004.09.002

1846

B. W. Reinisch, D. Bilitza / Advances in Space Research 34 (2004) 1845 1850

1960 when he accepted him as a graduate student at the"Ionosphdren Institut Breisach". Other graduate students at the time included Rolf Kraft, JRirgen Btichau
Fritz Fischer, Frank Ade, Gerhard Schmitdke, Christian Miinter, and Hans B6hnel. A life long friendshipconnected all of us until today, most of us now retired.
Sadly Fritz and Hans died early and Jfirgen, who together with BWR emigrated from Germany to theUSA, died 10 years ago. Rawer's institute gave us a firstopportunity to see real scientists and researchers in action: Ewald Harnischmacher Klaus Bibl, Rudolf Eyfrig,
Hannes Hesse, Adolf Paul, Klaus Jacobs. Karl Rawer
was born to lead and he did so by inspiring his coworkers and students, and by training young scientists fromaround the world.
On his way from Austria to Baden-Wtirttemberg at
the end of WW II, Karl and his family had stayed fora short while in Bayern, the native state of his wife, Waltraut. Of the seven children, their son Bernhard is here
today to witness the ceremony in honor of his father.
An unfortunate accident has hospitalized Mrs. Rawer
preventing her from accompanying Karl to Miltenberg,
as planned. Waltraut Rawer has made it possible forKarl to achieve a successful balance between a happy
family life and an extraordinary career.

2. International outreach
Building international "research bridges" out of Germany was one of Karl's important objectives in the postwar years, and international cooperation became theleitmotiv in his career. For many years he made weekly
trips from Breisach to Paris to lecture at the Sorbonne
University as a Professeur Associ&, in collaboration withhis friend Prof. Etienne Vassy. International travel inthe early 1960s was not as convenient as it is today
and we students had great respect for Professor Rawer's
strenuous schedule and of course his international recognition. We might have been even more impressed
would we have known about another Associ6 lecturing
at the Sorbonne at the same time, Robert Oppenheimer.
Rawer's URSI activities began in 1954, and he represented the German ionospheric research in the preparation of the International Geophysical Year, 1957/58. By
that time, ionospheric sounding was done in many countries around the world, but there were no common rules
for the scaling and interpretation of the ionograms,
making global studies difficult. Eight ionospheric experts joined and formed the Worldwide Sounding Committee under the leadership of Allen Shapley, Rawer
among them, Piggott and Rawer (1961) published theresults of the committee's work as a Handbook for the
Scaling of lonograms. At the URSI General Assemblyin Munich in 1966, Rawer was elected international

Vice-Chair of what is today commission G of URSI,
and served as Vice-Chair and then Chair until 1972.
Starting in the early 1950s, his institute developed scientific payloads for the newly developed French rocket"Veronique" for a first successful launch in 1954 in
the French Sahara. His space experience and the connections to international research groups made Prof. Rawer
the natural choice to take a leading role in the WestGerman National Committee of COSPAR. After thedeath of Julius Bartels in 1964, Rawer became its chairman. He vigorously exploited the opportunity that COSPAR offered to establish long lasting relationships
between scientists from west and east across the cold
war borders, but also with researchers in India and inhitherto neglected countries in the far East and Africa.
Better writers than we are required to fully describe
the impact of Karl's visionary activity on ionosphereand space research in the 20th century. As his former
students and early beneficiaries of his leadership, we
merely list a few highpoints that have impressed manyin our generation. In 1953, he published the first bookon the ionosphere, appropriately called Die lonosphdre,
which was later translated into English. Although by
inclination an experimentalist, he was a master ofdescribing and documenting new results and in sorting
existing knowledge, as he did in a series of handbooks.
Jointly with Kurt Suchy he wrote Radio Observationsof the Ionosphere, published in 1967 as Volume 111/I1
in the Geophysics Series of the Handbuch der Physik.
After Bartels's death in 1964, Karl Rawer became theeditor of the series and issued the next five volumes ofthe series, 111/111 to III/VII. We leave it to the historians
to count the huge number of his scientific and science
policy papers, there must be several hundred.
In the late 1960s, the Space Science Committee in
COSPAR decided to develop a "Standard Ionosphere
Model". Again the choice was clear who should lead thiseffort. Karl Rawer took on the challenge, mandated by
COSPAR and later URSI, and so in 1968 began theodyssey of the International Reference Ionosphere,
IRI, described in some detail below.

3. Rawer's institutes
Under most difficult post-war conditions an ionospheric vertical incidence sounding station came to life
in 1946 at Schloss Neuershausen, near Freiburg, under
the auspices of the French Sendee Prevision lonosph~rique de la Marine (SPIM). This was the beginning of along cooperation between French and German ionospheric prediction studies. Rawer then managed toestablish the "lonosphdren Institut" in Breisach under
the administrative control of the German postal service.
This institute gained international reputation in the fieldof ionospheric radio wave propagation and forecasting,B. W Reinisch, D. Bilitza / Advances in Space Research 34 (2004) 1845-1850

and instrumentation through its cooperation with research organizations in the USA and France, and joint
measurement campaigns in Italy, Greece, and Norway.
To complement the remote ground-based sensing
with radio waves by observations with space borne
instrumentation, the Fraunhofer Society authorized
Rawer to found a separate institute on Kronenstrassein Freiburg, the Arbeitsgruppe fUr Weltraumforschung,with project funding from the Deutsche Forschungsgemeinschaft, NASA, and the European Space Agency
ESRO. The launch of two successful satellite missions
with instrumentation from the Arbeitsgruppe, AEROS
in 1972 and AEROS-B in 1974, led to temperatureand ion composition data that became an important input to the IRI. Soon the building on Kronenstrasse became too small to house the expanding space research
activities, and the Fraunhofer Society built an expansive
institute in Freiburg-West, Karl Rawer was appointed
the director of this Institute for Space Research (later renamed Institute for Measuring Techniques), leading it
until his retirement in the late 1970s.

4. A brief history of the IRI
In the mid- 1960s it became clear that an international
standard model for the ionosphere was needed, similar
to the successfully established COSPAR International
Reference Atmosphere (CIRA) for the thermosphereparameters (CIRA, 1961). Such models are required
for the specifications of environmental parameters in
the thermosphere and ionosphere for the design ofspace-based instruments, for satellite orbit determination and control, for analysis of radioastronomy data,
satellite altimetry data, and many more applications.
Foreseeing the need for such a model, COSPAR in
1968 initiated the IRI project and asked Karl Rawer
to become its first chairman. Since that time until today,
Karl Rawer has been closely involved with the IRI effort
and has been the main reason for the great success andbroad application of this international standard representation of the ionosphere. It is therefore quite appropriate that we are celebrating Karl Rawer's 90thbirthday together with IRIs 35th anniversary. Table 1
lists the major IRI milestones throughout these past 35
years and highlights Karl Rawer's involvement. It also
shows that the IRI group, under the guidance of Karl
Rawer, has always tried to keep up with the rapidlychanging computer and network environment in an effort to provide the user community with fast and easy
access to the IRI model and its parameter.
It is interesting to note that the original IRI charterhad only asked "... to provide vertical profiles of themain ionospheric parameters for suitably chosen locations, hours, seasons, and levels of solar activity; representing monthly median conditions based on

1847

experimental evidence". The IRI group, of course,
quickly moved past the limitations in time and space,and its first major release [Rawer et al., 1978] already included global coverage for the electron density. COSPARs Terms of Reference for the IRI project now
state: "the task group was established to develop andimprove a standard model of the ionospheric plasma
parameters. The model should be primarily based on
experimental evidence using all available ground andspace data sources; theoretical considerations can be
helpful in bridging data gaps and for internal consistency checks. Where discrepancies exist between different
data sources the IRI team should promote critical discussion to establish the reliability of the different databases. IRI should be updated as new data become
available and as old data sources are fully evaluatedand exploited. IRI is a joint working group of COSPAR
and URSI. COSPARs prime interest is in a generaldescription of the ionosphere as part of the terrestrial
environment for the evaluation of environmental effects
on spacecraft and experiments in space. URSIs prime
interest is in the electron density part of IRI for defining
the background ionosphere for radiowave propagation
studies and applications".

5. IRI members, meetings and applications
Karl Rawer used four very important ingredients inestablishing the IRI success story:(1) Selection of working group members who provide agood, balanced cross-section in terms of the representation of different countries and continents (seeFig. 1) as well as in terms of the representation ofdifferent measurement techniques. This turned out
to be a great asset in getting access to all essential
ground and space data sets for ionosphericparameters.
(2) Annual IRI workshops (see Table 2) as the main
venue for discussing improvements and enhancements of the model. These workshops quickly
became the catalyst for a multitude of international
collaborations whose goal it was to improve specificaspects of the model. A trademark of these quite
informal meetings was (and is) the "Final discussion" session where the IRI team decides on the
improvements and additions to be included in thenext version of the model, and where "volunteers"
are enlisted to investigate new data sources and specific modeling questions for future model updates.
(3) Publication of the workshop papers initially inSpace Research, and later in Advances in Space
Research (Table 2), resulting in an excellent recordof the IRI activities. A unique series of publications now documents the international efforts in

B. W. Reinisch, D. Bilitza / Advances in Space Research 34 (2004) 1845-1850

1848
Table 1
IRI milestones
Year

Event

Description

1968
1969
1972

COSPAR establishes IRI WG
URSI joins in
Prelimenary set of tables (Rawer andRamakrishnan)
COSPAR Symposium, Konstanz, Germany(K. Rawer, Organizer) (Rawer, 1974)
URSI special report: IRI-79 (Rawer et al.,
1978)
World data center A for Solar-Terrestrial
Physics Report: IRI-79 (Rawer et al., 1981)
IRI-86 on floppy disk for use on Personal
Computers (PCs)
National Space Science Data Center(NSSDC) Report (Bilitza, 1990)

K. Rawer, Chair

1995

IRI-95 online (IRI web)

Improvements at low magnetic latitudes

1999

URSI resolution

2001

IRI -2001 with many improvements and newparameters (Bilitza, 2001; Reinisch andHuang, 1998, 1999)

IRI recognized as the international
standard for the ionosphere
Improvements: D-Fl-region, STORM,
and Intercosmos Te model. New
paramters: Fl probability, equatorial
vertical ion drift

1973
1978
1981
1986
1990

Media

IRI parameters at selected locations

ReportGuidelines established for data thatshould be used for D-region modeling
Global coverage for densities, CCIR
maps for foEfoF1,fF2, and M(3000)F2

Report, ALGOL and FORTRAN codeon punched tape/cards
Graphs and tables of IRI parameters

Global coverage for temperatures basedon AE-C,-D,-E and AEROS-A,-B data
URSI maps for foF2

Floppy disk with DOS interactive
programRetrievable from NSSDCs archive via
anonymous ftp and available for online
computation as part of NSSDCs Online
Data and Infromation Service (NODIS)IRI web: compute and plot IRI
parameters on the Internet

\

k'\

5.'
''N

'1
-5i

N,

Nt
N.'

\\'

.....

5,.....

5'. NS.<

Fig. 1. Members of the IRI working group come from many countries and continents.

ionospheric modeling. As the main editor of thesepublications Karl Rawer has helped countless
non-English speaking colleagues to correct theirlanguage and grammar and to publish their important results sometimes for the first time in an
English-language journal.

(4) Newest technology to make the IRI model quickly
and easily accessible to its wide user community
and its broad spectrum of applications. IRI was
one of the first international efforts to distributeits model in the form of computer codes in a number of different computer languages. In step with

B. W. Reinisch, D. Bilitza / Advances in Space Research 34 (2004) 1845 1850

1849

Table 2
IRI workshops and publications
Year

Location

Topic

Publication

1971a
Seattle, USA
1973
Konstanz, FRG
Measurements and results of lower ionosphere
1974a
Sao Paulo, Brazil
1980aBudapest, Hungary
International Reference Ionosphere - IRI-79
1982a
Ottawa, Canada
The upper atmosphere of the earth and planets
1983
Stara Zagora, Bulgaria
Towards an improved IRI
1984aGraz, Austria
Models of the atmosphere and ionosphere
1985
Louvain, Belgium
IRI - status 1985/19861986aToulouse, France
IRI - status 1986/1987
1987
Novgorod, Russia
Ionospheric informatics
1988a
Espoo, Finland
Ionospheric informatics and empirical modelling
1989
Abingdon, UK
Development of IRI-90
1990a
The Hague, Netherlands
Enlarged space and ground data base for
1991
Athens, Greece
Adv. in global/reg. descript. of ionospheric parameter
1992a
Washington, DC, USA
Ionospheric models
1993
Trieste, Italy
Off median phenomena and IRI
1994aHamburg, FRG
The high latitudes in the IRI
1995
New Dehli, India
Low and equat. latitudes in IRI
1996a
Birmingham, UK
Description of ionospheric storm effects and irregularities
1997
Kilhlungsborn, Germany
New develops, in ionospheric modelling and prediction
1998aNagoya, Japan
Lower ionosphere: measurements and models
1999
Lowell, MA, USA
IRI - workshop 1999
2000a
Warsaw, Poland
Modelling the topside ionosphere and plasmasphere
2001
Sao Jose dos Campos, Brazil
Description of the low latitude ionosphere in the IRI
2002'
Houston, Texas, USA
Improved ionosphere specification and forecast
2003
Grahamstown, South Africa
Quantifying ionospheric variability
a IRI session during the General Assembly of the Committee on Space Research.

Space Res. XII, 1229-1335, 1972
Akademie-Verlag, Berlin, 1974
Space Res. XV, 295-334, 1975
WDC-A-STP, UAG-90, 1984
Adv. Space Res. (ASR) 2(10) 1982
ASR 4 (1), 1984
ASR 5 (7), 1985
ASR 5 (10), 1985
ASR 7 (6), 1987
ASR 8 (4), 1988
ASR 10 (8), 1990
ASR 10 (11), 1990
ASR 11 (10), 1991
ASR 12 (7), 1992
ASR 13 (3), 1993
ASR 14 (12), 1994
ASR 16 (1), 1995
ASR 18 (6), 1996
ASR 20 (9), 1997
ASR 22 (6), 1998
ASR 25 (1), 2000
ASR 27 (1), 2001
ASR 29 (6), 2002
ASR 31 (3), 2003
ASR 33 (6), 2004
ASR, this issue

Table 3
Applications of the IRI modelStandard for engineering applications

IRI is used as the standard in "natural orbital environment definition guidelines for use in aerospacevehicle development" (NASA, 1994)
IRI is the standard ionosphere model in the System Engineering Handbook of the European
Cooperation for Space Standardization (ECSS, 1997)•IRI is under consideration to become the ISO standard for the ionospheric parameters (Bilitza
et al., 2004)
IRI is the ionosphere model used in ESA/ESTECs Space Environment Information System(SPENVIS) http:http://www.spenvis.oma.be/spenvis/, in NASA/MSFCs Space Environment
Effects (SEE) web interface http:http://see.msfc.nasa.gov/pf/models.html, and NASA Glenn
Research center's photovoltaic and space environments pages http:http://powerweb.grc.nasa.gov/
pvsee/info/movies/iri90.html

Visualization tool for educational
applications

IRI Total Electron Content (TEC) world maps (U. Leicester, UK) http:http://ion.le.ac.uli/remotesensinglmodels/tec.html
3-d electron density visualization using AVS (CRL, Tokyo, Japan) [Watari et al., 2003]

Ionospheric correction for singlefrequency satellite altimeters

Longtime data record of sea surface heights (Pathfinder Project); updating IRI with ionosonde data
[Bilitza et al., 1997; Lillibridge and Cheney, 1997]
Processing of ERS-1 and ERS-2 data products [CERSAT, 1996]
Work with Geosat Follow On (GFO) data [Navy-IGDR, 2000; Zhao et al., 2002]

Background ionosphere for evaluation ofdata mapping techniques

Testing algorithms that convert GPS measurements into global TEC maps [Hernandez-Pajares et al.,
2002]
TEC from NNSS Doppler measurements [Ciraolo and Spalla, 2002]
Testing algorithms that convert GPS measurements into global TEC maps [Hernandez-Pajares et al.,2002]

the computer revolution of the 1980s and 1990s, theprograms were first provided on nine-track tapes,
then on punched tapes and cards, then on floppy

disks, then online (ftp://nssdcftp.gsfc.nasa.gov/
models/), then as a PC windows code (http://umlcar.uml.edu/downloads.html) [Huang et al., 2001],

B. W. Reinisch, D. Bilitza / Advances in Space Research 34 (2004) 1845-1850

1850

and the latest incarnation is the IRI Web, aninterface that lets the user compute and plot IRI

parameters online (http://nssdc.gsfc.nasa.gov/space/models/iri.html).
The great legacy of Karl Rawer's push for an Interna-

tional Reference Ionosphere is best documented by the
many applications that depend on this model. Table 3
summarizes the most important applications.

6. Conclusions
Karl, we take this opportunity to thank you for what
you have done for geoscience, and for your leadershipthat affected so many of us assembled here today. The
large international audience attending this special session bears witness to your high standing as a scientist
and as a human being. We all wish you a happy 90thbirthday and good health for the years to come.

Acknowledgements
The authors gratefully acknowledge support throughAF Grant F19628-02-C-0092 and NSF Grant INT0002144.

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