This year will see the convening of the 2000 World Radio Conference and the termination of work on allocations between 71 and 275 GHz. It should also see the completion of the band- by-band study into the protection needs of radio astronomy and what consideration we can expect from other services. This is where we think we're at.

The Band-by-Band Study

The mandate of the band-by-band study is for a study of the protection needs of radio astronomy on a band-by-band basis, and a statement by the satellite industry as to what it feels is practical to provide by way of protection for us. In practice, it has already become a battle to justify, for each band, the level of protection we have. Since the limits on interference radiated in the radio astronomy bands were calculated on the basis of what we need to be able to observe effectively, we cannot relax those levels. However, the various national delegations don't see things in such terms. An illusion has been built up that the levels can set to a higher level as a compromise to suit all parties. We are working to educate the other parties in the discussions.

The situation is being exacerbated by the various lobbyists spreading the view that radio astronomy is a completely ivory- tower activity and should not be given the consideration that "useful radio services" deserve. Our counter arguments are that firstly radio astronomy is recognized as radio service by the ITU, and therefore has the right shared by all radio services so recognized, of having a right to operate effectively. This of course begs the question as to what these criteria happen to be. Moreover, they need to be similar to those applied to other radio services. Our second point is that we are not arguing against the implementation of the new services; we are opposing their saving money by allowing un-needed by-product signals to be radiated into bands allocated to radio astronomical applications.

Since we have to go through with this study, we have to grab the opportunities it provides, which are:

1. to show that the levels in RA769.1 (which states the maximum permissible levels of interference that other services can radiate into radio astronomy bands before damaging observations) must stay as they are;
2. to define a set of criteria that can be used to describe a window of time, frequency and power level that can be used by the ITU and licensing authorities to address interference problems;
3. to define areas where all concerned services can contribute to a solution - with the burden falling equally on all;
4. to define a measure of effectiveness that can be applied to radio observatories and other radio facilities.

1. not more than 5% of the observing time in an observing session, or of the total available observing time at any particular facility should be lost through man-made interference. This is an aggregate of all interference contributions. To maintain these limits, licensing authorities should not permit any single source of interference to degrade more than 2% of the total observing time;
2. cooperative scheduling may be used to some extent to mitigate interference problems. However, because of observation priorities and administrative overheads, the percentage of observing time committed to such arrangements should not be expected to exceed 15%;
3. radio observatories are expected to do all they can to minimize the sensitivities of radio telescopes to services in adjacent bands, and the active services in adjacent bands are also required to do everything possible to minimize their emissions of interference. If it is not possible through the combined efforts of all parties to avoid detrimental interference to radio astronomical observations, the interfering services cannot operate there;
4. some radio astronomy bands can be shared with other services (e.g., the situation in the 406.1-410MHz band), provided that geographic and operational factors prevent them interfering excessively (see 1.) with radio astronomical observations;

This approach shows our willingness to see the "Big Picture" and defines criteria that can be used in licensing and spectrum management. The effectiveness argument in terms of costs is the same as that which you would apply to any other radio service.

Our proposal is getting heavy opposition from the satellite lobby, but we have growing support in the Canadian and other national delegations. If we can get this through, we will be able to wrap up the band-by-band study in a way that respects the needs of radio astronomy and other services and helps to get us additional spectral coverage.

It might appear that our problem is that the ITU and our national spectrum managers in Industry Canada are pro-industry and anti-radio astronomy. This is not the case. They are trying very hard to balance a number of different interests. However, we are working with two handicaps: firstly although the spectrum managers at Industry Canada have a good, solid radio engineering background, they don't really understand radio astronomy. We are working hard to remedy this problem, and IC is quite appreciative of our efforts. The second problems is that we are few in number compared with the industry lobbyists and have not the resources or skills to compete in pressure. The policy we are adopting is to be as open, honest and helpful as possible, and always to promote a balanced view.

Stop Press I have just attended a meeting of ITU Working Party 7D in Orlando. The 5%/2% issue (see point 1 above) is now internationally agreed and will pass to the next level (Study Group 7). After that it needs passing at a world radio conference. There will be opposition, but it cannot now meaningfully come from Canada, UK, USA, The Netherlands, France, Russia or Germany, since they all supported it.

Frequencies Between 71 and 275 GHz

This issue has been going on for a while, and we seem at last to be converging on agreement. The atmosphere has changed from one of extreme urgency to one of "what's the hurry". I think that some people were surprised at the speed with which astronomers around the world achieved a common proposal. It showed that the other parties seeking spectral space were not always clear on what they wanted to do with it. They appear to be laying aside "investments for the future". However, our proposals have forced others to increase the level of detail in theirs.

These are the radio astronomy bands currently (more-or-less) agreed to internationally:

Bottom	Top	Status	Width of Band
<---(GHz)--->			(GHz)
76.0	77.5	(Primary)	1.5
77.5	78.0	(Secondary)	0.5
78.0	94.0	(Primary)	16.0
94.0	94.1	(Secondary)	0.1
94.1	116.0	(Primary)	21.9
123.0	130.0	(Secondary)	7.0
130.0	134.0	(Primary)	4.0
134.0	136.0	(Secondary)	2.0
136.0	158.5	(Primary)	22.5
164.0	167.0	(Primary)	3.0
200.0	231.5	(Primary)	31.5
235.0	238.0	(Primary)	3.0
241.0	248.0	(Primary)	7.0
250.0	275.0	(Primary)	25.0
			145.0

Mainly as primary users, more than 70% of the spectrum between 71 and 275 GHz is proposed for our use.

We should now be getting our thoughts together as to what we want between 275 and 1000 GHz because the allocations of these frequencies is coming up next, and will probably be on the agenda for the 2003 World Radio Conference.

Some Help from a "Free Radical"

Millimeter and submillimeter bands are of crucial interest to Canadian astronomers. It's therefore crucial that we have some on-line participation by someone conversant with millimeter and submillimeter matters. That lets me out. Fortunately Paul Feldman has agreed to come on board. As he is not bonded to any national delegation, as I am, he is free to interact with whomever he feels appropriate. He will play a big part in making our choices of what we want above 275GHz, and how we will protect our new observatories from the growing cacophony of man-made interference.

ken.tapping@hia.nrc.ca

Comments from Paul

Canada currently is a partner in the JCMT on Mauna Kea and hopes to join the international consortium building the ALMA array in Chile. The JCMT operates common-user heterodyne receivers in the 211-276, 318-373, 430-510, and 630-710 GHz ranges. On occasion, it has hosted guest instruments at other frequencies, especially in the 810 GHz band. The JCMT also features a continuum receiver (SCUBA) with wide bands in atmospheric windows ranging from 2000 to 350 microns (frequency coverage as high as 880 GHz). The ALMA specifications are not yet fixed, but it is expected that frequency coverage will be nearly continuous in all atmospheric windows ranging from 30 GHz to 700 GHz. At this time the 800-900 GHz window seems to be considered a possible option for a second phase of ALMA development.

I would like to solicit opinions from current and future users of both telescopes as to what they consider to be the highest priorities for frequency protection. The common molecular and atomic tracers of density and temperature are obvious candidates for strict protection. For example, I am confident that we will succeed without too much trouble in protecting the (accessible) CO lines from 345 to 922 GHz as well as the lines of their more abundant isotopomers (13CO, C18O, and C17O). It is much less obvious that radio astronomers will succeed in obtaining strict (or even good) protection for all the astrochemically interesting species that can be observed in the submm. Furthermore, because ALMA is being designed to be a sensitive probe of extragalactic gas, it is necessary to factor in the need to protect redshifted bands for the most easily detectable molecular and atomic species (e.g., the lower-J lines of CO and both fine-structure lines of CI).

The simple solution of requesting protection for radio astronomy across the entire 275-900 GHz range is simply not in the cards. The best we are likely to get, even after making an excellent scientific case, is protection for a sizable fraction of the band (similar to what we anticipate for the 75-275 GHz allocations). Even better would be an early designation of the Chilean Llano de Chajnantor site as a special radio-interference-free zone, subject to much stricter and more comprehensive limits on radio interference than the rest of the planet. (It would be useful to have a similar designation for the Island of Hawaii, but this is a very unlikely possibility.)

I need your opinions and input sooner than later. I anticipate that a fierce battle for frequencies above 275 GHz will begin in a few months, after the 75-275 GHz allocations are made. We have to be ready with our priorities. Satellite-satellite communications at high frequencies is already a reality, with a Canadian company part of the first wave. Now is the time to begin staking our claims.

Paul.Feldman@hia.nrc.ca

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