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WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Workshop on Radio Frequencies for MeteorologyWorkshop on Radio Frequencies for MeteorologyMarch 20/21, 2006, GenevaMarch 20/21, 2006, Geneva
Hans Richner, IACHans Richner, IACETHETH, Zurich, Zurich
WMOWMOWorld Weather WatchWorld Weather Watch
Commission on Basic SystemsCommission on Basic SystemsSteering Group Radiofrequency CoordinationSteering Group Radiofrequency Coordination
Ground-based passive sensorsGround-based passive sensors
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Sources and Acknowledgments:
This presentation is primarily based in information which is freely available on the internet.
Some of the figures were presented at the Workshop "Active Protection of Passive Radio Services: towards a concerted strategy." Contributors were:
Ambrosini, Roberto IRABaan, Willem AstronCohen, Jim Jodrell Bankde La Noe, Jerome Obs. de BordeauxDeschamps, Andre Obs. de ParisFeist, Dietrich Univ. BerneFejes, Istvan FOMILazareff, Bernard IRAMMarelli, Edoardo ESAMartinelli, Massimo ESFMeens, Vincent CNESMillenaar, Rob AstronMureddu, Leonardo INAF OAC
Otter, Manfred ESAPorceddu, Ignazio INAF OACRichner, Hans WMORochard, Guy † Meteo FranceRommen, Bjorn ESARuf, Klaus DLRSpoelstra, Titus Astron/CRAFStruzak, Ryszard formerly ITU RRBUrban, Joachim Chalmers Univ.van Driel, Wim IUCAFvonDeak, Tom NASAWheeler, Bill UK Met OfficeWolf, Robert EUMETSAT
The Workshop was organized by the European Science Foundation.
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
1. principle of molecular spectrum
2. interference mechanisms
3. future threats
4. what should be done
Overview
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
principle of molecular spectra
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
O3,CH3Cl, HOCl, ClO, HNO3, N2O, H2O2, HCN, BrO, SO2, ...
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Institute for Applied Physics, University of Bern (IAP)
ASMUWARA, the All-Sky MUlti WAvelength RAdiometer
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Frequency bands and bandwidths used for passive sensing (1)
Frequency BW(GHz) (MHz) main measurements
1.4 - 1.427 100 soil moisture, salinity, ocean surface temperature, vegetation index
2.69 - 2.70 60 salinity, soil moisture4.2 - 4.4 200 ocean surface temperature6.7 - 7.1 400 ocean surface temperature (no allocation)
10.6 - 10.7 100 rain, snow, ice, sea state, ocean wind, ocean surface temperature, soil moisture
15.35 - 15.40 200 water vapour, rain18.6 - 18.8 200 rain, sea state, ocean ice, water vapour, snow 21.2 - 21.4 200 water vapour, cloud liquid water
22.21 - 22.50 300 water vapour, cloud liquid water23.6 - 24.0 400 water vapour, cloud liquid water31.3 - 31.8 500 window channel associated to temperature
measurements36 - 37 1000 rain, snow, ocean ice, water vapour,
cloud liquid water, ocean wind, soil moisture
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Frequency bands and bandwidths used for passive sensing (2)Frequency BW
(GHz) (MHz) main measurements50.2 - 50.4 200 O2 (temperature profiling)52.6 - 59.3 6700 O2 (temperature profiling)
86 - 92 6000 Clouds, ice, snow, rain100 - 102 2000 N2O
109.5 - 111.8 2300 O3114.25 - 122.25 8000 O2 (temperature profiling), CO148.5 - 151.5 3000 window channel155.5 - 158.5 3000 window channel (to be terminated on 1 January 2018)
164 - 167 3000 window channel174.8 - 191.8 17000 H2O (moisture profiling), N2O, O3
200 - 209 9000 H2O, O3, N2O226 - 232 6000 clouds, CO235 - 238 3000 O3250 – 252 2000 N2O275 – 277 2000 N2O
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Frequency bands and bandwidths used for passive sensing (3)Frequency BW
(GHz) (MHz) Main measurements294 – 306 12000 N2O, O3, O2, HNO3, HOCl316 – 334 10000 water vapour profiling, O3, HOCl342 – 349 7000 CO, HNO3, CH3Cl, O3, O2, HOCl, H2O363 – 365 2000 O3371 – 389 18000 water vapour profiling416 – 434 18000 temperature profiling442 – 444 2000 water vapour486 – 506 9000 O3, CH3Cl, N2O, BrO, ClO546 – 568 22000 temperature profiling624 – 629 5000 BrO, O3, HCl, SO2, H2O2, HOCl, HNO3634 – 654 20000 CH3Cl, HOCl, ClO, H2O, N2O, BrO, O3, HO2, HNO3659 – 661 2000 BrO684 – 692 8000 ClO, CO, CH3Cl730 – 732 2000 O2, HNO3851 – 853 2000 NO951 – 956 5000 O2, NO, H2O
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
intermediate conclusion:
evidently, the electro-magnetic spectrum is a very precious natural
resource!!!it must be protected, on the other hand reasonable use has to accepted
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
oxygen lines around 60 GHz
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Weighting function for MSU at nadir
• Weighting function has a peak at specific altitude
• Each channel had different sensitivity to altitudes
• by measuring at several channels within the steep slope of the O2 absorption spectrum
and correcting for several factors (for which information is obtainable in the 31 GHz and 24 GHz frequency bands), an accurate temperature profile of the atmosphere results
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
water vapor absorption around 24 GHz
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Frequency hoppingthe basics of Ultras Wide Band (UWB) systems
frequency
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
principle of UWB (Ultra Wide Band) systems
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Jodrell Bank UK
compared to radioastronomers, meteorologists are really modest:
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Measurements in the 10.6 to
10.7 GHz band with the
Effelsberg 100 m radio
telescope
… but both have the same problems:
normal
with a UWB system active
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
• Site control
• Jodrell Bank Consultation Zone
• Protection of particular frequency bands to agreed distances e.g. TV channel 38, 606-614 MHz
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Greenbank Radio-Quiet Zone
1956 West Virginia state law puts zoning restrictions on the use of electrical equipment within 10 miles of any radio astronomy facility.
1958 National Radio Quiet Zone established by FCC: 13,000 square miles of Virginia and West Virginia.
(The laws were set up before the radio telescopes were built and before any frequency bands were allocated to the RAS.)
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Network for the detection of Stratospheric Change
Measurements:
ground-basedbut alsoballoon-borneairbornesatellite-borne
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Remote sensing of the atmosphere: ground-based used frequencies
ATMOSPHERIC OPACITY IN FREQUENCY RANGE 1-275 GHz
1.E-07
1.E-06
1.E-05
1.E-04
1.E-03
1.E-02
1.E-01
1.E+00
1.E+01
1.E+02
1.E+03
1 26 51 76 101 126 151 176 201 226 251
Frequency (GHz)
Vertical opacity (dB)
Minor constituents
OxygenWater vapour tropical
Water vapour sub-arctic
Range10 to 280 GHz 22 GHz H2O110 GHz O3
142 GHz O3
183 GHz H2O
200-210 GHz O3, ClO, HNO3, N2O, HO2
H218O, HO2
265-280 GHzO3, ClO, HCN, HNO3, N2O
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Some ground-based microwave radiometers
University of BernMIAWARA: Middle Atmospheric Water Vapor Radiometer22 GHz, H20 line
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
University Bordeaux 1/OASUFloirac => Pic du MidiOzone microwave radiometer110.836 GHz, O3 line
Some ground-based microwave radiometers
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
University of BernGROMOS: Radiometer142 GHz, O3 line
Some ground-based microwave radiometers
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
University of BremenUniv. BordeauxDanish Meteorology Institute, University of Leeds
Radiometer at Summit: RAMASSIS junction, cooled to 4 K
265 to 281 GHzO3, ClO, HCN, HNO3, N2O
Some ground-based microwave radiometers
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Mitigation methods - howadaptive cancellation using reference antennas
F. Briggs
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Resultsadaptive cancellation
• WSRT example, using neighboring telescopes as reference antennas– observation at 355 MHz– crosscorrelation RT 5 and 6
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
GALILEO30 satellites in3 orbits
GLONASS13 satellites in3 orbits
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Picture from http://www.ee.surrey.ac.uk/Personal/L.Wood/constellations/teledesic.html
• LEO satellites promised better solution + services in polar regions
• Teledesic: 840 (1994)
or 288 (1997) active satellites – suspended Oct.
2002 and died
Low-Earth-Orbit Constellations
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Stratospheric radio
• Radio station at stratospheric heights, or constellations of such stations
• HAPS = High-Altitude Platform Station • The concept similar to that of LEO satellites but reduced to
stratospheric heights
• Cheaper than terrestrial or satellite radio• Satisfy “business” needs (profit), military needs,• “humanitarian” needs (“digital gap”)
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Helios
On June 26, 2003, the Helios aircraft was lost
in the Pacific Ocean (Hawaii) during tests of a
new fuel cell system for
overnight flight operations in the
stratosphere
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Japan’s project
• Constellation (dozens) of stations
• Operational in 2008
• Long. 250.0 m weight 32.0 t payload 1.0 tpower 10.0 kW
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
“Stratospheric satellites” StratoSatTM
Model of Fully-Pressurized Balloons In Flight. Picture courtesy of NASA.
• Constellation of stratospheric balloons powered by solar array
• Could be steered/ directed to fly over specific areas
• Payloads up to 2 tons at ~35 km
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
StratoSatTM
• 400 stations/hemisphere
• Projected life: 3 to 10 years.
• Costs: 10 to 100 times less than present space satellite or aircraft communications platforms
according to http://www.gaerospace.com/ (06.2002)
– Infrastructure: < $ 160 million
– Operation: < $ 10 million per year
– Life-cycle cost < $ 400,000 per unit
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Space Data
• “Swarm” - millions (?) of low-cost “weather-type” balloons moving freely with the wind
• Reusable payload • Built from “of-the-shelf” low-cost components
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Footnote to Radio Regulations:
S5.340 All emissions are prohibited in the following bands:1 400 - 1 427 MHz2 690 - 2 700 MHz except those provided for by Nos. S5.421 an S5.42210.68 - 10.7 GHz except those provided for by No. S5.483 15.35 - 15.4 GHz except those provided for by No. S5.511 23.6 - 24 GHz31.3-31.5 GHz31.5-31.8 GHz in Region 248.94-49.04 GHz from airborne stations51.4-54.25 GHz58.2-59 GHz64-65 GHz86-92 GHz105-116 GHz140.69-140.98 GHz from airborne stations and from space stations in the
space-to-Earth direction182-185 GHz except those provided for by No. S5.563217-231 GHz.
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Footnote to Radio Regulations:
S5.340 All emissions are prohibited in the following bands:1 400 - 1 427 MHz2 690 - 2 700 MHz except those provided for by Nos. S5.421 an S5.42210.68 - 10.7 GHz except those provided for by No. S5.483 15.35 - 15.4 GHz except those provided for by No. S5.511 23.6 - 24 GHz…..…..
particularly disturbing:
unwanted emissions: consist of spurious emissions and out-of-band emissions
we all know: there are unwanted emissions!
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
out-of-band emissions: Emissions on a frequency or frequencies immediately outside the necessary band- width which results from the modulation process, but excluding spurious emissions
spurious emissions: Emissions on a frequency or frequencies which are outside the necessary bandwidth and the level of which may be reduced without affecting the corresponding transmission of information. Spurious emissions include harmonic emissions, parasitic emissions, intermodulation products and frequencies and frequency conversion products, but exclude out-of-band emissions.
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Footnote to Radio Regulations:
S5.340 All emissions are prohibited in the following bands:1 400 - 1 427 MHz2 690 - 2 700 MHz except those provided for by Nos. S5.421 an S5.42210.68 - 10.7 GHz except those provided for by No. S5.483 15.35 - 15.4 GHz except those provided for by No. S5.511 23.6 - 24 GHz
intentional
particularly disturbing:
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Re-radiation
• Terrestrial radiations reflected by the HAPS
• Threat of nullifying terrain shadowing and direction selectivity
• Not treated in the Radio Regulations
HAPS
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
absorption lines between 275 GHz and 1 THz -- tomorrows resources!?
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Satellite versus conventional: NH height
Sat data largest
impact ~10 hr gain
Fore
cast
skill
Roger Saunders, SFCG24
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Sat data largest
impact ~ 48 hr gain
Satellite versus conventional: SH heightFore
cast
skill
Roger Saunders, SFCG24
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Conclusions and recommendations (1)
Radiofrequency issues for ground-based passive systems are basically the same as for other, say, space-based passive systems.
Potential interference of active systems depends much on the siting.
Topographic shielding might prove to be not effective due to re-radiation (reflection).
Air and/or space-borne emissions are generally more problematic for ground-based passive systems than terrestrial sources.
The biggest threat for any passive sensor are ultra wide band (UWB) systems; even if they do not cause direct interference, they increase the noise level.
The number of interference sources is ever increasing; ground-based, satellites, high altitude platforms.
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Conclusions and recommendations (2)
To a limited extent, mitigation techniques will allow observations in contami-nated bands.
Mitigation is the second choice, primarily interference must be avoided.
The dialog with the telecommunication community must be improved.
Bands currently protected by Radio Regulations must not be used by UWB systems!
The scientific community should carefully select those bands which must be protected; it will not be possible to protect all bands.
The scientific community should take all steps necessary for keeping some frequency bands free on any intentional emission - including ultra wide band.
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
Conclusions and recommendations (3)
Protection requirements in the not yet regulated frequency bands (>275 GHz)should be formulated before this band is used by active systems.
The operators of ground-based passive systems are poorly organized.
The operators of ground-based systems should compile an inventory of their instruments.
All operators of passive systems should combine their protection efforts.
As technology progresses, higher frequencies are used.
In many countries, the cooperation between telecom administrations and the scientific and meteorological community should be intensified.
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva(thanks to Guy Rochard, † Dec 05)
Mr. Telecom
some unknown scientist
WMO SG RFC: Radio Frequencies for Meteorology: Ground-based passive sensors
Hans Richner, IACETH, March 20/21, 2006, Geneva
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