MEETING REPORT
Active Protection of Passive Radio Services: towards a concerted strategy
A workshop on "Active Protection of Passive Radio Services: towards a concerted strategy"
was held in Cagliari, Sardinia, Italy, on 28th and 29th October 2004. The workshop was
sponsored by the European Science Foundation, with additional support from RadioNet. The
meeting addressed the threats to scientific use of passive radio frequency bands from rapidly
increasing use of the radio spectrum, from growing levels of radio pollution, and from
commercial pressures to relax regulatory control. Deregulation is used to increase
competition in the market, but how can passive users compete? The meeting brought
together for the first time the radio astronomical and remote sensing communities, in a
relaxed informal venue. There were 26 delegates from 9 countries, who between them
represented 5 national and international space agencies, the meteorology community, the
aeronomy community, the geodetic community, and 6 major radio astronomy observatories.
The meeting venue, the Hotel Panorama, was only 35 km from the site where the Sardinia
Radio Telescope (SRT) is under construction. Nichi D'Amico (INAF-OAC Director)
welcomed participants and gave a presentation on the SRT project. The SRT will be a 64-m
diameter dish with an active primary mirror, enabling it to cover a very wide frequency range
of 0.3-100.0 GHz, with fast switching between operating frequencies.
The full workshop programme is given in the Appendix to this report. The first day covered
the scientific needs of the different communities. Willem Baan and Bernard Lazareff
described major new radio astronomy facilities under construction or planned for the twenty
first century. These will have 100 times the sensitivity of current instruments and will cover
wide frequency bands in order to detect spectral lines from distant galaxies that have been
redshifted outside the protected bands, because of the expansion of the Universe. New
techniques of interference mitigation are being developed to enable successful observations
to be made in these circumstances, as described by Rob Millenaar. But the need for globally
coordinated VLBI observations and for single dish surveys means that the protection of
passive frequency bands will also remain a top priority for the foreseeable future.
Hans Richner and Guy Rochard described the frequency use for climate monitoring,
meteorology and environmental studies including monitoring of greenhouse gases such as
CO2, CH4, O3 and CH3Cl. The work includes active and passive measurements from space,
from the ground and using radio sondes and other meteorological aids. The developments in
ultra-wide band (UWB) devices including those for short range radar on cars have
highlighted the need to make the radio community aware of passive frequency uses and
techniques, and to make meteorologists more aware that the radio spectrum is not unlimited,
so that constructive dialogue can start. We need to be ready to justify every single frequency
allocation and to explain what the true cost would be if the World Meteorological
Organization were to lose the use of different bands.
The UWB situation was discussed by Vincent Meens. Current studies specify assumed
densities of devices, their location (indoor or outdoor) and level of activity, but in practice
how can these parameters be controlled? Studies have raised the issue of apportionment of
interference among different sources, which is being pursued within ITU-R, as described by
Thomas vonDeak. The question of whether interference can be mitigated is being raised.
However it is impossible to mitigate very low level interference either in passive sensing or
radio astronomy. A passive sensor simply integrates the total power across the band, so if
there is an interfering component this will result in wrong data being recorded and processed,
and eventually in a wrong weather forecast. Robert Wolf explained the situation at 24 GHz,
where car manufacturers want to use a frequency that breaks all the ITU rules, simply
because a cheap chip is available right now. The expected interference to satellite sensors
will affect measurements at many frequencies, since the 24-GHz measurements are used to
calibrate other bands.
Jerome de la Noe described techniques for studying the middle atmosphere from the ground
using passive microwave radiometry to obtain vertical profiles of atmospheric gases. The
Network for Detection of Stratospheric Change (NDSC) runs monitoring stations that have
no official status within the ITU, but which play an important complementary role to satellite
sensors, tracking time evolution. Limb sounding from space using the ODIN satellite at
submm wavelengths was discussed by Joachim Urban, while Dietrich Feist described
stratospheric sounding of water vapour from aircraft, and interference over certain regions.
Istvan Fejes, a self-confessed cuckoo in the nest, described the use of global navigation
satellites for Earth science: tectonics, Earth rotation and atmospheric sensing. He reported
on a GNSS interference programme carried out at the Central European GPS Geodynamic
Reference Network (CEGRN) sites. The UN Office on Outer Space Affairs (NOOSA) is
interested to set up a global working group on Site quality, integrity and interference
monitoring.
Among many emerging issues, Titus Spoelstra spoke about powerline communications,
broad band multimedia from satellites and the concept of interference temperature as a tool
for squeezing more users into the radio spectrum, while Ryszard Struzak described
developments in stratospheric radio using aircraft and balloon platforms to cover wide
service areas cheaply. The scientific community needs observer status at the EC discussions
and elsewhere, to know what is coming.
The second day covered political and structural issues, and the forward look. Massimo
Martinelli explained the role of the ESF, its aims and its instruments, including workshops
such as this one. As a recognized non-governmental body covering more countries than the
EC, the ESF might be able to help us in our negotiations at European level.
Klaus Ruf described the development of the concept of passive radio services within the ITU,
and the protection afforded to the passive frequency bands. However UWB is not a service,
and indications are that our protection will depend on our own skills in defending our
interests within TG1/8 and elsewhere. Titus Spoelstra emphasised the need for all passive
services to present a coherent agreed position within the ITU, CEPT, national administrations
and the general public, and to improve our visibility to all these groups.
The organization and role of IUCAF was explained by the Chairman, Wim van Driel. ICSU
in its recent review recommended that IUCAF becomes truly interdisciplinary to take care of
all passive services. The meeting was strongly in favour of adding lectures on remote
sensing to the second IUCAF Summer School in Spectrum Management, to be held in June
2005. Edoardo Marelli, Chairman of the SFCG, described the structure and objectives of
SFCG. Although passive sensing is only one aspect of SFGC activity, it is one of the most
important. Participation of radio astronomers as observers has proved very useful and
perhaps the presence of other passive users could also be useful. SFCG helped to broker the
agreement on coordinating future cloud radar missions at 94 GHz with radio astronomy
operations.
Forthcoming WRC agenda items of interest to the passive services were introduced in a
series of talks by Jim Cohen, Manfred Otter and Bjorn Rommen, the details of which can be
found in their presentations.
The heart of the workshop was the subsequent Open Discussion chaired by Edoardo Marelli,
which covered the following topics:
1. Organizational Situation. Much can be achieved by a pragmatic small steps approach.
The need for personal representation of the two groups on each others' committees was
reiterated. Good liaison will ensure that early alarms are raised. Better coordination and
exchange of information can help us all. It was agreed that an internet-based forum (such as
a wiki) would facilitate this. Willem Baan and Ignazio Porceddu agreed to investigate the
possibilities for setting this up on the Astron or Cagliari web sites. It was felt that the CRAFIUCAF Summer School 2005 will be of interest to the passive sensing community, and
should include some lectures on those issues. In the longer term a more formal structural
solution could come through enlarging the mandate and constitution of IUCAF.
2. Political Aspect. The discussions were primarily concerned with influencing European
policy, since most participants were from European organizations. We need to target the
decision makers in frequency management at national level, so they can support us better
internationally. We need to stress the economic value of keeping passive frequency bands
empty not just with qualitative arguments but by providing real figures. We also need to
improve our high level contacts so that our case is known at political level. One aim in
Europe is to get observer status for the ESF at the RSPG (Radio Spectrum Policy Group) as a
general (neutral) representative of the science community. Roberto Ambrosini will
investigate.
3. Regulatory Situation. Within Europe, very few of the 45 CEPT national authorities are
sufficiently aware of the need to protect passive services. Also at EC level our needs are not
understood. We need to increase this awareness, to avoid the situation where individual
national administrations take (uniformed) unilateral actions to our detriment. We need to
lobby for pre-launch tests of unwanted emissions from satellites, for improved monitoring of
frequency usage, and for respect of the ITU rules. In the long term we need a definition of
the ground-based passive atmospheric sensors as a service, perhaps via meteorological aids.
4. WRC-07 Specific Issues. We already have good coordination and common positions on
unwanted emission and 1.4 GHz. For the WRC-10 agenda we need good coordination on the
agenda item for frequencies above 275 GHz, to ensure that we have a compelling case before
the WRC-10 agenda is decided at WRC-07. It was decided that our 3 contact points for the
three areas should be Wim van Driel (radio), Guy Rochard (passive sensing from satellites)
and Jerome de la Noe (passive sensing from the ground). The contact persons are to gather
data, perhaps via the new wiki, and we will try to make a workshop to merge the 3 cases. In
the long term we need to develop a position on the question of regulation of optical and
infrared frequencies.
Summary
The Workshop recognized the common interests of our groups as one. We use passive bands
for astronomy, for remote sensing from satellites and from the ground, but we all rely for the
integrity of our work on the passive bands being truly passive. We identified a big problem
of perception of the needs of passive band activities and their socio-economic importance.
We identified a need to gather our arguments for the preservation of each individual passive
band (what would be lost?) and to make this information more widely known. A list of
action items was drawn up. It was agreed that we should aim to have a follow-up workshop
in 2006.
Action Items.
(a) Establish an internet forum (wiki) - Willem Baan and Ignazio Porceddu;
(b) Try to get ESF observer status on RSPG - Roberto Ambrosini to investigate;
(c) Establish contact group on above 275 GHz issues – Wim van Driel, Guy Rochard and
Jerome de la Noe to gather information from their respective communities;
(d) Meeting report - action Jim Cohen;
(e) Update presentations and send them to Ignazio Porceddu – action all speakers;
(f) publish the report and presentations on the web - action Ignazio Porceddu;
(g) produce policy statement suitable to use in contacts with officials, administrations, the
EC, etc. - action on the organizing committee;
(h) Include passive sensing lectures in the 2005 Summer School - action IUCAF and CRAF.
(i) Organize future workshop, probably in 2006, to focus on >275 GHz issues – action all.
APPENDIX: Meeting Schedule
"Active Protection of Passive Radio Services: towards a concerted strategy"
Hotel Panorama, Cagliari, Sardinia, Italy,
28-29 October 2004
PROGRAMME
28th October (Scientific and Technical Issues)
09.00-13.00
Chair: Jim Cohen
Nichi D’Amico, INAF-OAC Director and SRT Board
“Presentation of the SRT Project”
09.00 Opening Welcome:
1. Existing frequency allocations and how they are used
“Radio Astronomy in the Twenty First Century”
09.15 Willem Baan (Astron)
09.50 Hans Richner (WMO)
“The needs for protection of frequencies used for
passive sensing in meteorology, climatology and environmental studies”
“Passive Microwave Protection”
10.10 Guy Rochard (Meteo-France)
10.30 Bernard Lazareff (IRAM)
“Millimetre and Submillimetre Wave Astronomy”
10.45-11.15 COFFEE BREAK
11.15 Jerome de la Noe (Observatoire de Bordeaux)
sensing of the middle atmosphere”
“Frequency needs for remote
2. Operational issues, interference, emerging threats
11.40 Thomas vonDeak (NASA) “Detection and the impact of man-made interference on
EES (passive) sensor operations”
12.25 Vincent Meens (CNES)
“The problem of in-band emission in purely passive
bands: some examples with the Ultra Wide Band transmissions”
13.00-14.30 LUNCH
14.30-17.45 Chair: Jerome de la Noe
14.30 Robert Wolf (EUMETSAT) “Short Range Radar Issues”
14.50 Joachim Urban (RSS Chalmers Uni.)
“Spaceborne observations of the middle
atmosphere at sub-mm wavelengths: ODIN/SMR and future sensors”
“Measurements of atmospheric water vapour at
15.10 Dietrich Feist (Uni. of Berne)
22 GHz and 183 GHz”
“Interference Mitigation in Radio Astronomy”
15.35 Rob Millenaar (Astron)
16.00-16.30 COFFEE BREAK
16.30 Istvan Fejes (FOMI Satellite Geodetic Observatory)
“Interference Monitoring
in the Central European GPS Geodynamic Reference Network”
16.50 Titus Spoelstra (CRAF)
“Emerging Issues: interference temperature, PLC, etc”
17.10 Ryszard Struzak (ITU)
“Emerging stratospheric radio”
29th October (Political and Structural Issues)
09.00-13.00 Chair: Roberto Ambrosini
3. Existing organizations and how to strengthen them
09.00 Massimo Martinelli (ESF)
09.15 Klaus Ruf (DLR)
“The Role of the ESF”
“Passive Services and the ITU”
09.40 Wim van Driel (IUCAF)
“IUCAF and the Protection of the Passive Services"
10.00 Edoardo Marelli (ESA)
structure and objectives”
“The Space Frequency Coordination Group (SFCG)
10.20 Titus Spoelstra (CRAF)
“European Concert: consonants and dissonants”
10.45-11.15 COFFEE BREAK
4. The way ahead
11.15 Jim Cohen (JBO)
“Forthcoming WRC-07 and WRC-10 Agenda Items of interest
for radio astronomy”
11.45 Manfred Otter (ESA) “WRC-07 agenda items of interst to passive services with
particular emphasis on 1.2 and 1.17”
“WRC-07 Agenda Item 1.20 and protection of the
12.15 Bjorn Rommen (ESA)
EESS (passive)”
13.00-14.30 LUNCH
14.00-17.45 Chair: Edoardo Marelli
5. Panel Discussion
Suggested topics include:

Possible new organizational links and collaborations

Do we need an ITU-R definition of passive service?

Forthcoming WRC-07 and WRC-10 agenda items, and how to prepare common
positions for them (e.g. FSS at 1.4 GHz, protection of the submm bands 275-1000
GHz)

Outreach: how to make the best case for the passive bands and how to raise
awareness of the issues so that everyone knows what is at stake

Policy statement or press release to be issued by workshop?
16.00-16.30 COFFEE BREAK
16.30 Panel Discussion continued
17.30 Workshop Summary
END OF WORKSHOP
Saturday 30th October Visit to Site of Sardinia Radio Telescope
08.45 Departure from Hotel
10.00 Arrival to site and start of the visit of the Sardinia Radio Telescope (SRT) now under
construction
12. 00 Departure from site and transfer to LUNCH place,
“spuntino” in Sardinian style (=big)
14.00 End of visit, transfer to the airport
15.00 Arrival at the Cagliari airport
PARTICIPANTS’ EMAIL LIST
Ambrosini, Roberto
Baan, Willem
Cohen, Jim
de La Noe, Jerome
Deschamps, Andre
Feist, Dietrich
Fejes, Istvan
Lazareff, Bernard
Marelli, Edoardo
Martinelli, Massimo
Meens, Vincent
Millenaar, Rob
Mureddu, Leonardo
Otter, Manfred
Porceddu, Ignazio
Richner, Hans
Rochard, Guy
Rommen, Bjorn
Ruf, Klaus
Spoelstra, Titus
Struzak, Ryszard
Urban, Joachim
van Driel, Wim
vonDeak, Tom
Wheeler, Bill
Wolf, Robert
IRA
Astron
Jodrell Bank
Obs.de Bordeaux
Obs.de Paris
Uni. Berne
FOMI
IRAM
ESA
ESF
CNES
Astron
INAF OAC
ESA
INAF OAC
WMO
Meteo France
ESA
DLR
Astron/CRAF
formerly ITU RRB
Chalmers Uni.
IUCAF
NASA
UK Met Office
EUMETSAT
r.ambrosini@ira.cnr.it
baan@astron.nl
rjc@jb.man.ac.uk
Jerome-de.La.Noe@obs.u-bordeaux1.fr
andre.deschamps@obspm.fr
dietrich.feist@mw.iap.unibe.ch
fejesi@sgo.fomi.hu
lazareff@iram.fr
Edoardo.Marelli@esa.int
massimo@ipcf.cnr.it
vincent.meens@libertysurf.fr
millenaar@astron.nl
mureddu@ca.astro.it
ManOtter@t-online.de
iporcedd@ca.astro.it
hans.richner@ethz.ch
guy.rochard@meteo.fr
Bjorn.Rommen@esa.int
Klaus.Ruf@dlr.de
spoelstra@astron.nl
ryszard.struzak@bluewin.ch
jo.urban@rss.chalmers.se
Wim.vanDriel@obspm.fr
Thomas.C.vonDeak@nasa.gov
bill.wheeler@metoffice.com
Wolf@eumetsat.de