29 th October 2004ESF Workshop, Cagliari WRC-07 and WRC-10 Agenda Items Important for Radio Astronomy Jim Cohen Jim Cohen Jodrell Bank Observatory University of Manchester Jodrell Bank Observatory University of Manchester 29 th October th October 2004

ESF Workshop, Cagliari WRC-07 agenda items 1.7, 1.8, 1.11, 1.17, 1.21 WRC-10 agenda item 2.2 (sub-mm bands) Radio-Quiet Zones WRC-07 agenda items 1.7, 1.8, 1.11, 1.17, 1.21 WRC-10 agenda item 2.2 (sub-mm bands) Radio-Quiet Zones Outline of Talk

29 th October 2004ESF Workshop, Cagliari 1.7 to consider the results of ITU-R studies regarding sharing between the mobile-satellite service and the space research service (passive) in the band MHz, and between the mobile-satellite service and the mobile service in the band MHz in accordance with Resolution 744 [COM5/12](WRC-03); WRC-03 allocated 7 MHz to MSS (INMARSAT): studies of SRS and MS sharing afterwards! Space-based VLBI (very long baseline interferometry) telescopes operate in the space research (passive) service, since 1997 (Japanese HALCA 8-m dish). 1.7 MSS and SRS (passive)

29 th October 2004ESF Workshop, Cagliari 1.8 High Altitude Platform Stations (HAPS) 1.8 to consider the results of ITU-R studies on technical sharing and regulatory provisions for the application of high altitude platform stations operating in the bands GHz and GHz in response to Resolution 145 [COM5/17] (WRC-03), and for high altitude platform stations operating in the bands GHz and GHz in response to Resolution 122 (Rev.WRC-03); In Bhutan, Korea (Rep. of), the Russian Federation, Indonesia, Iran (Islamic Republic of), Japan, Kazakhstan, Lesotho, Malaysia, Maldives, Mongolia, Myanmar, Uzbekistan, Pakistan, Philippines, Kyrgyzstan, the Dem. People’s Rep. of Korea, Sri Lanka, Thailand and Viet Nam. 300 MHz sub-band ↓, with GHz ground-to-HAPS.

29 th October 2004ESF Workshop, Cagliari Footnote 5.543A … Systems using HAPS in the band GHz shall not cause harmful interference to the radio astronomy service having a primary allocation in the band GHz, taking into account the protection criterion as given in Recommendation ITU ‑ R RA.769. … 5.BC07The power flux-density in the band GHz produced by any geostationary space station in the fixed-satellite service (space-to-Earth) operating in the bands GHz and GHz shall not exceed –151.8 dB(W/m2) in any 500 kHz band at the site of any radio astronomy station. (WRC ‑ 03) Current Protection

29 th October 2004ESF Workshop, Cagliari 1.11 to review sharing criteria and regulatory provisions for the protection of terrestrial services, in particular terrestrial television broadcasting services, in the band MHz from BSS networks and systems, in accordance with Resolution 545 [COM4/5](WRC-03) ; 1.11 HEOs Highly elliptical orbits (HEOs) HEO constellation ground track

29 th October 2004ESF Workshop, Cagliari WORKING DOCUMENT TOWARDS A PDNR ON PROTECTION OF THE RADIOASTRONOMY SERVICE FROM UNWANTED EMISSIONS OF HEO BSS SYSTEMS OPERATING IN THE BAND MHZ [ANFR1] TABLE 5 Maximum pfd levels per HEO BSS satellite to protect RAS RAS band (MHz) pfd limit per satellite (dBW/m 2 ) Reference bandwidth (MHz) (reference) (spectral line) (continuum) (spectral line) Epfd limits to protect RA bands at 610 MHz and 1400 MHz; pfd per satellite reduced by 74 dB from maximum radiated.

29 th October 2004ESF Workshop, Cagliari 1.11 HEOs 2% of sky blockage at zenith Article 22.5C.1 Equivalent power flux density (epfd) is the sum of the pfds produced by a satellite system, taking into account the off-axis discrimination of a reference antenna. Calculation of the effect of a HEO constellation, in terms of epfd. In some parts of the sky there is a high probability of interference.

29 th October 2004ESF Workshop, Cagliari 1.17 to consider the results of ITU-R studies of compatibility between the fixed satellite service and other services around 1.4 GHz, in accordance with Resolution 745[COM5/14](WRC-03); further resolves to invite ITU-R, as a matter of urgency 3 to carry out studies, including the measurement of emissions from equipment that would be employed in operational systems, to validate that the systems meet all requirements for the protection of passive services in the band MHz from unwanted emissions from FSS feeder links around 1.4 GHz for non ‑ GSO satellite systems in the MSS with service links operating below 1 GHz; 1.17 FSS Feeder Links near 1.4 GHz

29 th October 2004ESF Workshop, Cagliari % of sky blockage at horizon WDTPDNR-1 pfd limit per satellite to protect RAS: 90dB of rejection needed. This time the interference is near the horizon.

29 th October 2004ESF Workshop, Cagliari WDTPDNR-2 Assuming an unwanted emission power limit of –60 dBW radiated in the band MHz by MSS feeder link Earth stations operating in the band ‑ MHz, (imposed by the protection of the EESS), it is necessary to have a protection zone around each RAS station operating in this band of radius of about km. Based on 98% propagation loss (blockage). FSS Uplink 2% of blockage near horizon 2% + 2% + 2 % + … of passive band lost

29 th October 2004ESF Workshop, Cagliari 1.21 Band by band studies TG1/ to consider the results of studies regarding compatibility between the radio astronomy service and the active space services in accordance with Resolution 740[COM4/17](WRC-03) in order to review and update, if appropriate, the Tables of threshold levels used for consultation that appear in the Annex to Resolution 739[COM4/15](WRC-03); TG1/3, 1/5, 1/7, 1/9 (a long sad history)

29 th October 2004ESF Workshop, Cagliari Line of sight: can’t shield against them! Global coverage: all terrestrial sites affected Spread spectrum: radio pollution of passive bands Many satellite bands near radio astronomy bands Many examples (GLONASS, Astra, Tex, Iridium, … ) Malfunctions are difficult to repair in space Long timescale for change, once launched More than 100 satellites launched per year No pre-launch check on total emissions (environmental impact) Satellite Interference to RA

29 th October 2004ESF Workshop, Cagliari Appendix 3 Spurious Emission Limits for Satellites (TG1/5, WRC-00) LEO GSO RA.769 For new satellites from 2003 and all satellites from 2012 After 6 years!

29 th October 2004ESF Workshop, Cagliari resolves 1that an administration takes all reasonable steps to ensure that space stations being designed and constructed to operate in the bands in the Annex meet the values given therein at any radio astronomy station operating in the corresponding bands identified in the Annex; 2… if the unwanted emissions from the space station cannot meet the values given in the Annex … b)the concerned administrations enter into a consultation process in order to identify further steps with a view to achieving a mutually acceptable solution; Res.739 (WRC-03) TG1/7

29 th October 2004ESF Workshop, Cagliari Further band pairs are under study in TG1/9, for WRC-07. But unwanted emission levels are not measured before launch anyway! What incentive to get it right? In the event of interference the ITU-R recommends consultation. Will this help RA? WP4A continues to be unhelpful, e.g. new PNDR Practical Levels of Unwanted Emissions. However, when new satellite allocations are made, RA limits are accepted into the RR (via new Footnotes). TG1/9 and WRC-07

29 th October 2004ESF Workshop, Cagliari 7.2 WRC-10 Agenda 2.2to consider frequency allocations between 275 GHz and GHz taking into account the result of ITU-R studies in accordance with Resolution 950 [COM7/1](WRC-03); resolves 2That administrations may submit for inclusion in the Master International Frequency Register details on systems which operate between 275 and GHz … Currently Footnote identifies frequency bands within the range GHz that are used by passive services for spectral line measurements.

29 th October 2004ESF Workshop, Cagliari WRC-2000 Results Success takes time and planning. We need to start now, preparing our sub-mm case and agreeing our common position.

29 th October 2004ESF Workshop, Cagliari 2.7to consider the progress of ITU-R studies concerning the technical and regulatory issues relative to the fixed service in the 81 ‑ 86 and GHz frequency bands, taking into account Resolutions 731 (WRC ‑ 2000) and 732 (WRC ‑ 2000); (FS,MS,RA sharing) RES731to determine if and under what conditions sharing is possible between active and passive services in the bands above 71 GHz RES732 that appropriate measures should be taken to meet the spectrum requirements for active services for which the technology will be commercially available at a later time. 2.7 Review > 71GHz

29 th October 2004ESF Workshop, Cagliari Radio-Quiet Reserves ITU-R Working Party 7D, Draft New Question 2004 (answer by WRC-2010) 1.What are the characteristics of existing radio quiet zones? 2.What characteristics of the instruments of the Radio Astronomy Service have stimulated the development of radio quiet zones? 3.What characteristics of the electromagnetic environment stimulated the development of radio quiet zones?

29 th October 2004ESF Workshop, Cagliari Site control Jodrell Bank Consultation Zone Protection of particular frequency bands to agreed distances e.g. TV channel 38, MHz

29 th October 2004ESF Workshop, Cagliari ITU-R Radio Regulations: Passive frequency bands; protection from recognized radio transmitters; coordination procedures for transmitters in- band or in nearby bands. Local and National Law: Radio-Quiet Zones governing any electrical interference, not just from radio transmitters. May be helpful against new technologies such as PLC. Site Control: Self-protection from astronomers and modern electronics! Layers of Protection

29 th October 2004ESF Workshop, Cagliari Screened box for 2 Workstations Computers Radiate in Passive Bands Galaxy-like emissions recorded at ~10 Jy

29 th October 2004ESF Workshop, Cagliari 1956 West Virginia state law puts zoning restrictions on the use of electrical equipment within 10 miles of any radio astronomy facility 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 West Virginia state law puts zoning restrictions on the use of electrical equipment within 10 miles of any radio astronomy facility 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. Greenbank Radio-Quiet Zone

29 th October 2004ESF Workshop, Cagliari Cerro-Chascón Science Preserve (ALMA) Protected against mining etc. by Chilean Government Supreme Decree No. 185, June 1998 San Pedro 2,500 m ALMA 5,000 m

29 th October 2004ESF Workshop, Cagliari ALMA Quiet Zone Exempt Resolution No. 1055, 17 August Protection for primary allocated bands, via zones. 30-km radius Protection Zone: no transmitters in RA bands used by ALMA. 120-km Coordination Zone: transmitters in RA bands only by negotiation/coordination. Limits to unwanted emissions based on Rec.RA Plus eirp limits on all transmitters in Coordination Zone operating below 31.3 GHz. No protection from satellites or HAPS, or mobiles outside the Protection zone.

29 th October 2004ESF Workshop, Cagliari Forte Satellite: Earth at 131 MHz Radio-quiet zones (controlled emission zones) can provide extra protection for new mega-facilities such as SKA that will need to observe outside the allocated frequency bands. What about LOFAR? ?