ITU-R RA 314-10-2003 Preferred frequency bands for radio astronomical measurements《射电天文业务在与其他业务共享频段内的保护》.pdf

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1、 Rec. ITU-R RA.314-10 1 RECOMMENDATION ITU-R RA.314-10 Preferred frequency bands for radio astronomical measurements (Question ITU-R 145/7) (1953-1956-1959-1966-1970-1974-1978-1982-1986-1990-1992-2002-2003) The ITU Radiocommunication Assembly, considering a) that the development of radio astronomy h

2、as led to major technological advances, particularly in receiving techniques and to improved knowledge of fundamental radio-noise limitations of great importance to radiocommunication, and promises further important results; b) that the advancement of radio astronomy requires the protection of certa

3、in frequency bands from interference; c) that the International Astronomical Union (IAU) is maintaining and updating the list of spectral lines of the greatest importance to radio astronomy; d) that radio astronomers study spectral lines both in bands allocated to the radio astronomy service and, as

4、 far as spectrum usage by other services allows, outside the allocated bands, and that this has resulted in the detection of more than 3 000 spectral lines as illustrated in Fig. 1 of Annex 1; e) that account should be taken of the Doppler shifts of the lines, due to the relative motion of source an

5、d observer; f) that certain frequency bands have been allocated for continuum observations, and that the exact positions of these bands in the spectrum are not of critical importance, but that their centre frequencies should be in the ratio not more than two to one, taking the width of relevant atmo

6、spheric windows into account; g) that radio astronomers have made useful astronomical observations from the Earths surface in all available atmospheric windows ranging from 2 MHz to 1 000 GHz and above; h) that the technique of space radio astronomy, which involves the use of radio telescopes on spa

7、ce platforms, provides access to the entire radio spectrum above about 10 kHz, including parts of the spectrum not accessible from the Earth due to absorption in the atmosphere; j) that some types of high-resolution interferometric observations require simultaneous reception, at the same radio frequ

8、ency, by receiving systems located in different countries, on different continents, or on space platforms; k) that world administrative radio conferences and world radiocommunication conferences have made improved frequency allocations for radio astronomy, but that protection in many bands, particul

9、arly those shared with other services, may still need careful planning, 2 Rec. ITU-R RA.314-10 recommends 1 that administrations should afford all practicable protection to the frequencies used by radio astronomers in their own and neighbouring countries; 2 that particular attention should be given

10、to securing or maintaining adequate protection for the frequency bands listed in Tables 1 and 2, which contain rest frequencies and Doppler-shifted frequencies of the astrophysically most important spectral lines identified by the General Assembly of the IAU, and in Table 3, which contains the frequ

11、ency bands allocated to the radio astronomy service that are preferred for continuum observations; 3 that administrations be asked to provide assistance in the coordination of observations of spectral lines in bands not allocated to radio astronomy. TABLE 1 Radio-frequency lines of the greatest impo

12、rtance to radio astronomy at frequencies below 275 GHz Substance Rest frequency Suggested minimum band Notes(1)Deuterium (DI) 327.384 MHz 327.0-327.7 MHz Hydrogen (HI) 1 420.406 MHz 1 370.0-1 427.0 MHz (2), (3) Hydroxyl radical (OH) 1 612.231 MHz 1 606.8-1 613.8 MHz (4) Hydroxyl radical (OH) 1 665.4

13、02 MHz 1 659.8-1 667.1 MHz (4) Hydroxyl radical (OH) 1 667.359 MHz 1 661.8-1 669.0 MHz (4) Hydroxyl radical (OH) 1 720.530 MHz 1 714.8-1 722.2 MHz (3), (4) Methyladyne (CH) 3 263.794 MHz 3 252.9-3 267.1 MHz (3), (4) Methyladyne (CH) 3 335.481 MHz 3 324.4-3 338.8 MHz (3), (4) Methyladyne (CH) 3 349.1

14、93 MHz 3 338.0-3 352.5 MHz (3), (4) Formaldehyde (H2CO) 4 829.660 MHz 4 813.6-4 834.5 MHz (3), (4) Methanol (CH3OH) 6 668.518 MHz 6 661.8-6 675.2 MHz (3) Helium (3He+) 8 665.650 MHz 8 657.0-8 674.3 MHz (3), (6) Methanol (CH3OH) 12.178 GHz 12.17-12.19 GHz (3), (6) Formaldehyde (H2CO) 14.488 GHz 14.44

15、-14.50 GHz (3), (4) Cyclopropenylidene (C3H2) 18.343 GHz 18.28-18.36 GHz (3), (4), (6) Water vapour (H2O) 22.235 GHz 22.16-22.26 GHz (3), (4) Ammonia (NH3) 23.694 GHz 23.61-23.71 GHz (4) Ammonia (NH3) 23.723 GHz 23.64-23.74 GHz (4) Ammonia (NH3) 23.870 GHz 23.79-23.89 GHz (4) Sulphur monoxide (SO) 3

16、0.002 GHz 29.97-30.03 GHz (6) Methanol (CH3OH) 36.169 GHz 36.13-36.21 GHz (6) Silicon monoxide (SiO) 42.519 GHz 42.47-42.57 GHz (6), (8) Silicon monoxide (SiO) 42.821 GHz 42.77-42.86 GHz Silicon monoxide (SiO) 43.122 GHz 43.07-43.17 GHz Silicon monoxide (SiO) 43.424 GHz 43.37-43.47 GHz Dicarbon mono

17、sulphide (CCS) 45.379 GHz 45.33-45.44 GHz (6) Rec. ITU-R RA.314-10 3 TABLE 1 (end) Substance Rest frequency Suggested minimum band Notes(1)Carbon monosulphide (CS) 48.991 GHz 48.94-49.04 GHz Oxygen (O2) 61.1 GHz 56.31-63.06 GHz (5), (6), (7) Deuterated water (HDO) 80.578 GHz 80.50-80.66 GHz Cyclopro

18、penylidene (C3H2) 85.339 GHz 85.05-85.42 GHz Silicon monoxide (SiO) 86.243 GHz 86.16-86.33 GHz Formylium (H13CO+) 86.754 GHz 86.66-86.84 GHz Silicon monoxide (SiO) 86.847 GHz 86.76-86.93 GHz Ethynyl radical (C2H) 87.3 GHz 87.21-87.39 GHz (5) Hydrogen cyanide (HCN) 88.632 GHz 88.34-88.72 GHz (4) Form

19、ylium (HCO+) 89.189 GHz 88.89-89.28 GHz (4) Hydrogen isocyanide (HNC) 90.664 GHz 90.57-90.76 GHz Diazenylium (N2H+) 93.174 GHz 93.07-93.27 GHz Carbon monosulphide (CS) 97.981 GHz 97.65-98.08 GHz (4) Sulphur monoxide (SO) 99.300 GHz 99.98-100.18 GHz Methyl acetylene (CH3C2H) 102.5 GHz 102.39-102.60 G

20、Hz (5) Methanol (CH3OH) 107.014 GHz 106.91-107.12 GHz Carbon monoxide (C18O) 109.782 GHz 109.67-109.89 GHz Carbon monoxide (13CO) 110.201 GHz 109.83-110.31 GHz (4) Carbon monoxide (C17O) 112.359 GHz 112.25-112.47 GHz (6) Cyano radical (CN) 113.5 GHz 113.39-113.61 GHz (5) Carbon monoxide (CO) 115.271

21、 GHz 114.88-115.39 GHz (4) Oxygen (O2) 118.750 GHz 118.63-118.87 GHz (7) Formaldehyde (H213CO) 137.450 GHz 137.31-137.59 GHz (6) Formaldehyde (H2CO) 140.840 GHz 140.69-140.98 GHz Carbon monosulphide (CS) 146.969 GHz 146.82-147.12 GHz Nitric oxide (NO) 150.4 GHz 149.95-150.85 GHz (5) Methanol (CH3OH)

22、 156.602 GHz 156.45-156.76 GHz Water vapour (H2O) 183.310 GHz 183.12-183.50 GHz Carbon monoxide (C18O) 219.560 GHz 219.34-219.78 GHz Carbon monoxide (13CO) 220.399 GHz 219.67-220.62 GHz (4) Cyano radical (CN) 226.6 GHz 226.37-226.83 GHz (5) Cyano radical (CN) 226.8 GHz 226.57-227.03 GHz (5) Carbon m

23、onoxide (CO) 230.538 GHz 229.77-230.77 GHz (4) Carbon monosulphide (CS) 244.953 GHz 244.72-245.20 GHz (6) Nitric oxide (NO) 250.6 GHz 250.35-250.85 GHz (5) Ethynyl radical (C2H) 262.0 GHz 261.74-262.26 GHz (5) Hydrogen cyanide (HCN) 265.886 GHz 265.62-266.15 GHz Formylium (HCO+) 267.557 GHz 267.29-2

24、67.83 GHz Hydrogen isocyanide (HNC) 271.981 GHz 271.71-272.25 GHz 4 Rec. ITU-R RA.314-10 Notes relating to Table 1: (1)If Notes (2)or (4)are not listed, the band limits are the Doppler-shifted frequencies corresponding to radial velocities of 300 km/s (consistent with line radiation occurring in our

25、 galaxy). (2)An extension to lower frequency of the allocation of 1 400-1 427 MHz is required to allow for the higher Doppler shifts for HI observed in distant galaxies. (3)The current international allocation is not primary and/or does not meet bandwidth requirements. See the Radio Regulations (RR)

26、 for more detailed information. (4)Because these line frequencies are also being used for observing other galaxies, the listed bandwidths include Doppler shifts corresponding to radial velocities of up to 1 000 km/s. It should be noted that HI has been observed at frequencies redshifted to 500 MHz,

27、while some lines of the most abundant molecules have been detected in galaxies with velocities up to 50 000 km/s, corresponding to a frequency reduction of up to 17%. (5)There are several closely spaced lines associated with these molecules. The listed bands are wide enough to permit observations of

28、 all lines. (6)This line frequency is not mentioned in RR Article 5. (7)These lines are observable only outside the atmosphere. (8)A portion of the “suggested minimum band” for this line extends outside the band allocated to the radio astronomy service. Protection for observations conducted in this

29、portion of the band may not be practicable. NOTE 1 A more extended list of astrophysically important and often observed line frequencies, the “Recommended Rest Frequencies for Observed Interstellar Molecular Microwave Transitions”, is maintained by a group at the National Institute of Standards and

30、Technology (NIST) in Gaithersburg, Maryland, United States of America, (http:/physics.nist.gov/PhysRefData/).TABLE 2 Radio-frequency lines of the greatest importance to radio astronomy at frequencies between 275 and 1 000 GHz (not allocated in the RR) Substance Rest frequency (GHz) Suggested minimum

31、 band (GHz) Notes(1)Diazenylium (N2H+) 279.511 279.23-279.79 Carbon monosulphide (CS) 293.912 292.93-294.21 Hydronium (H3O+) 307.192 306.88-307.50Deuterated water (HDO) 313.750 313.44-314.06 Carbon monoxide (C18O) 329.330 329.00-329.66Carbon monoxide (13CO) 330.587 330.25-330.92 Carbon monosulphide

32、(CS) 342.883 342.54-343.23 Carbon monoxide (CO) 345.796 345.45-346.14 Hydrogen cyanide (HCN) 354.484 354.13-354.84 Rec. ITU-R RA.314-10 5 TABLE 2 (continued) Substance Rest frequency (GHz) Suggested minimum band (GHz) Notes(1)Formylium (HCO+) 356.734 356.37-357.09 Oxygen (O2) 368.498 368.13-368.87Di

33、azenylium (N2H+) 372.672 372.30-373.05 (2) Water vapour (H2O) 380.197 379.81-380.58(2) Hydronium (H3O+) 388.459 388.07-388.85 Carbon monosulphide (CS) 391.847 390.54-392.24 Oxygen (O2) 424.763 424.34-425.19Carbon monoxide (C18O) 439.088 438.64-439.53 Carbon monoxide (13CO) 440.765 440.32-441.21Carbo

34、n monoxide (CO) 461.041 460.57-461.51 Deuterated water (HDO) 464.925 464.46-465.39 Carbon (C) 492.162 491.66-492.66 Deuterated water (HDO) 509.292 508.78-509.80 Hydrogen cyanide (HCN) 531.716 529.94-532.25 (2) Carbon monosulphide (CS) 538.689 536.89-539.23 (2) Water vapour (H218O) 547.676 547.13-548

35、.22(2) Carbon monoxide (13CO) 550.926 549.09-551.48 (2) Water vapour (H2O) 556.936 556.37-557.50(2) Ammonia (15NH3) 572.113 571.54-572.69(2) Ammonia (NH3) 572.498 571.92-573.07 (2) Carbon monoxide (CO) 576.268 574.35-576.84 (2) Carbon monosulphide (CS) 587.616 587.03-588.20 (2) Deuterated water (HDO

36、) 599.927 599.33-600.53 (2) Water vapour (H2O) 620.700 620.08-621.32(2) Hydrogen chloride (HCI) 625.040 624.27-625.67 Hydrogen chloride (HCI) 625.980 625.35-626.61 Carbon monosulphide (CS) 636.532 634.41-637.17 Carbon monoxide (13CO) 661.067 658.86-661.73Carbon monoxide (CO) 691.473 690.78-692.17 Ox

37、ygen (O2) 715.393 714.68-716.11(2) Carbon monosulphide (CS) 734.324 733.59-735.06 (2) Water vapour (H2O) 752.033 751.28-752.79(2) Oxygen (O2) 773.840 773.07-784.61(2) Hydrogen cyanide (HCN) 797.433 796.64-798.23 Formylium (HCO+)802.653 801.85-803.85Carbon monoxide (CO) 806.652 805.85-807.46 Carbon (

38、C) 809.350 808.54-810.16 Carbon monosulphide (CS) 832.057 829.28-832.89 Oxygen (O2) 834.146 833.31-834.986 Rec. ITU-R RA.314-10 TABLE 2 (end) TABLE 3 Frequency bands allocated to the radio astronomy service that are preferred for continuum observations Substance Rest frequency (GHz) Suggested minimu

39、m band (GHz) Notes(1)Carbon monosulphide (CS) 880.899 877.96-881.78 Water vapour (H2O) 916.172 915.26-917.09(2) Carbon monoxide (CO) 921.800 918.72-922.72 (2) Carbon monosulphide (CS) 929.723 926.62-930.65 Water vapour (H2O) 970.315 969.34-971.29(2) Carbon monosulphide (CS) 978.529 977.55-979.51 (2)

40、 Water vapour (H2O) 987.927 986.94-988.92(2) (1)The band limits are the Doppler-shifted frequencies corresponding to radial velocities of 300 km/s (consistent with line radiation occurring in our galaxy). (2)These lines are observable only outside the atmosphere. Frequency band (MHz) Frequency band

41、(GHz) 13.360-13.410 10.6-10.7 25.550-25.670 15.35-15.4 37.5-38.25(1)22.21-22.50 73-74.6(2)23.6-24.0 150.05-153(3)31.3-31.8 322-328.6 42.5-43.5 406.1-410 76-116(1)608-614(4)1 400-1 427 123-158.5(1)1 660-1 670 164-167 2 655-2 700(1)200-231.5 4 800-5 000(1)241-275(1)(1)These bands include secondary all

42、ocations. (2) Allocation (primary) in Region 2, protection recommended in Regions 1 and 3. (3)Allocation (primary) in Region 1, Australia and India. (4)Allocation (primary) in Region 2, the African Broadcasting Area (606-614 MHz), China (606-614 MHz) and India. In Region 1 (except the African Broadc

43、asting Area) and in Region 3 this band is allocated on a secondary basis. Rec. ITU-R RA.314-10 7 Annex 1 0314-01020 40 60 80100 0100100100100100120140160180200220240260280300320340360380400420440460480500520540560580600200150100500FIGURE 1Frequency distribution of spectral lines detected by radio as

44、tronomical observations andatmospheric transparency below 600 GHz10.80.60.40.20Frequency (GHz)Number of spectral linesAtmospheric transparencyNumberofspectrallinesAtmospherictransparencyNote Histogram shows the number of currently detected spectral lines, in 5 GHz bins. Several lines have been detec

45、ted above 600-625.9 GHz (HCI), 691.5 GHz (CO), 806.9 GHz (CO) and 809.3 GHz (C). The US standard atmosphere model was used for the calculation of atmospheric transparency. The transparency was calculated in every 5 GHz bin for: altitude = 4.2 km, H2O pressure = 1 mm precipitation, and pressure = 640 hPa. Atmospheric transparency is the fraction of energy from outside of the atmosphere, that reaches the surface of the Earth. It can be related with the atmospheric attenuation by attenuation (dB) = 10 log (transparency).