1、 Recommendation ITU-R P.528-3(02/2012)Propagation curves for aeronautical mobileand radionavigation services usingthe VHF, UHF and SHF bandsP SeriesRadiowave propagationii Rec. ITU-R P.528-3 Foreword The role of the Radiocommunication Sector is to ensure the rational, equitable, efficient and econom
2、ical use of the radio-frequency spectrum by all radiocommunication services, including satellite services, and carry out studies without limit of frequency range on the basis of which Recommendations are adopted. The regulatory and policy functions of the Radiocommunication Sector are performed by W
3、orld and Regional Radiocommunication Conferences and Radiocommunication Assemblies supported by Study Groups. Policy on Intellectual Property Right (IPR) ITU-R policy on IPR is described in the Common Patent Policy for ITU-T/ITU-R/ISO/IEC referenced in Annex 1 of Resolution ITU-R 1. Forms to be used
4、 for the submission of patent statements and licensing declarations by patent holders are available from http:/www.itu.int/ITU-R/go/patents/en where the Guidelines for Implementation of the Common Patent Policy for ITU-T/ITU-R/ISO/IEC and the ITU-R patent information database can also be found. Seri
5、es of ITU-R Recommendations (Also available online at http:/www.itu.int/publ/R-REC/en) Series Title BO Satellite delivery BR Recording for production, archival and play-out; film for television BS Broadcasting service (sound) BT Broadcasting service (television) F Fixed service M Mobile, radiodeterm
6、ination, amateur and related satellite services P Radiowave propagation RA Radio astronomy RS Remote sensing systems S Fixed-satellite service SA Space applications and meteorology SF Frequency sharing and coordination between fixed-satellite and fixed service systems SM Spectrum management SNG Sate
7、llite news gathering TF Time signals and frequency standards emissions V Vocabulary and related subjects Note: This ITU-R Recommendation was approved in English under the procedure detailed in Resolution ITU-R 1. Electronic Publication Geneva, 2012 ITU 2012 All rights reserved. No part of this publi
8、cation may be reproduced, by any means whatsoever, without written permission of ITU. Rec. ITU-R P.528-3 1 RECOMMENDATION ITU-R P.528-3*,*Propagation curves for aeronautical mobile and radionavigation services using the VHF, UHF and SHF bands (Question ITU-R 203/3) (1978-1982-1986-2012) Scope This R
9、ecommendation contains a method for predicting basic transmission loss in the frequency range 125-15 500 MHz for aeronautical and satellite services. The method uses an interpolation method on basic transmission loss data from sets of curves. These sets of curves are valid for ground-air, ground-sat
10、ellite, air-air, air-satellite, and satellite-satellite links. The only data needed for this method are the distance between antennas, the heights of the antennas above mean sea level, the frequency, and the time percentage. This Recommendation, also, gives the calculations for the expected protecti
11、on ratio or wanted-to-unwanted signal ratio exceeded at the receiver for at least 95% of the time, R (0.95). This calculation requires the following additional data for both the wanted and unwanted signals: the transmitted power, the gain of transmitting antenna, and the gain of receiving antenna. T
12、he ITU Radiocommunication Assembly, considering a) that there is a need to give guidance to engineers in the planning of radio services in the VHF, UHF, and SHF bands; b) that the propagation model used to generate the curves given in Annex 2 is based on a considerable amount of experimental data (s
13、ee Annex 1); c) that the aeronautical service often provides a safety of life function and therefore requires a higher standard of availability than many other services; d) that a time availability of 0.95 should be used to obtain more reliable service, recommends 1 that the curves given in Annex 3
14、be adopted to determine the basic transmission losses for 1%, 5%, 10%, 50% and 95% of the time for antenna heights (for both the ground station and aircraft) likely to be encountered in the aeronautical services. NOTE 1 It must be emphasized that these curves are based on data obtained mainly for a
15、continental temperate climate. The curves should be used with caution for other climates. NOTE 2 The curves give basic transmission loss, that is, the loss between ideal loss-free isotropic antennas. Where surface reflection multipath at the ground station or the facility has been mitigated using co
16、unterpoises or a directional vertical radiation pattern suitable antenna radiation patterns should be included within analysis. *This Recommendation is brought to the attention of Study Group 5. *Radiocommunication Study Group 3 made editorial amendments to this Recommendation in 2000 in accordance
17、with Resolution ITU-R 44. 2 Rec. ITU-R P.528-3 Annex 1 Development and application of the curves Transmission loss prediction methods have been extended and incorporated into the IF-77 propagation model that determine basic transmission losses for 1%, 5%, 10%, 50% and 95% of the time for 10%, antenn
18、a heights applicable to the aeronautical services. These methods are based on a considerable amount of experimental data, and extensive comparisons of predictions with data have been made. In performing these calculations, a smooth (terrain parameter h = 0) Earth with an effective Earth radius facto
19、r k of 4/3 (surface refractivity Ns= 301) was used along with compensation for the excessive ray bending associated with the k = 4/3 model at high altitudes. Constants for average ground horizontal polarization, isotropic antennas, and long-term power fading statistics for a continental temperate cl
20、imate were also used. Although these parameters may be considered either reasonable or worst-case for many applications, the curves should be used with caution if conditions differ drastically from those assumed. With the exception of a region “near” the radio horizon, values of median basic transmi
21、ssion loss for “within-the-horizon” paths were obtained by adding the attenuation due to atmospheric absorption (in decibels) to the transmission loss corresponding to free-space conditions. Within the region “near” the radio horizon, values of the transmission loss were calculated using geometric o
22、ptics, to account for interference between the direct ray and a ray reflected from the surface of the Earth. Segments of curves resulting from these two methods were joined to form a curve that shows median basic transmission loss as increasing monotonically with distance. The two-ray interference m
23、odel was not used exclusively for within-the-horizon calculations, because the lobing structure obtained from it for short paths is highly dependent on surface characteristics (roughness as well as electrical constants), atmospheric conditions (the effective Earth radius is variable in time), and an
24、tenna characteristics (polarization, orientation and gain pattern). Such curves would often be more misleading than useful, i.e., the detailed structure of the lobing is highly dependent on parameters that are difficult to determine with sufficient precision. However, the lobing structure is given s
25、tatistical consideration in the calculation of variability. For time availabilities other than 0.50, the basic transmission loss, Lb, curves do not always increase monotonically with distance. This occurs because variability changes with distance can sometimes overcome the median level changes. Vari
26、ability includes contributions from both hourly-median or long-term power fading and within-the-hour or short-term phase interference fading. Both surface reflection and tropospheric multipath are included in the short-term fading. The curves provided in Annex 3 are selected curves from a much large
27、r set of computer-generated smoothed curves. The basic transmission loss, Lb(0.05) curves may be used to estimate Lbvalues for an unwanted interfering signal that is exceeded during 95% (100% 5%) of the time. Median (50%) propagation conditions may be estimated with the Lb(0.50) curves. The Lb(0.95)
28、 curves may be used to estimate the service range for a wanted signal at which service would be available for 95% of the time in the absence of interference. The expected protection ratio or wanted-to-unwanted signal ratio exceeded at the receiver for at least 95% of the time, R(0.95), can be estima
29、ted using the Annex 3 curves as follows: R(0.95) = R(0.50) + YR(0.95) (1) R(0.50) = Pt+ Gt+ Gr Lb(0.50)Wanted Pt+ Gt+ Gr Lb(0.50)Unwanted(2) Rec. ITU-R P.528-3 3 and YR= Lb(0.95) Lb(0.50)2Wanted+ Lb(0.05) Lb(0.50)2Unwanted(3) In equation (2), Ptis the transmitted power, and Gtand Grare the isotropic
30、 gains of the transmitting and receiving antennas expressed in dB. Additional variabilities could easily be included in equation (3) for such things as antenna gain when variabilities for them can be determined. Continuous (100%) or simultaneous channel utilization is implicit in the R(0.95) formula
31、tion provided above so that the impact of intermittent transmitter operation must be considered separately. Although transmission loss values may be read directly from the curves presented as figures in Annex 3 of this Recommendation, there are tabulated transmission loss values available. See that
32、part of the ITU-R website dealing with Radiocommunication Study Group 3. The tabulated data is available on the SG 3 website. Annex 2 Description of interpolation methods 1 Introduction This Annex describes separate stages of the calculation. A step-by-step description of the overall interpolation m
33、ethod is given in 8 of this Annex. Section 2 gives the calculation for field strength from the transmission loss value(s) taken from the curves in Annex 3. Sections 3 to 8 of this Annex describe how to interpolate for distance, h1, h2,frequency and percentage time. 2 Equivalent field strength The fi
34、eld strength equivalent to a given transmission loss is given by: fLEtlog203.139 += dB (V/m) (4) where: E : field strength (dB (V/m) for 1 kW e.r.p. Lt: transmission loss (dB) f : frequency (MHz). 4 Rec. ITU-R P.528-3 3 Antenna heights, h1and h2If the value of h1or h2coincides with one of the height
35、s for which curves are provided, the required transmission loss values may be obtained directly from the plotted curves or the associated tabulations. Otherwise the required transmission loss should be interpolated from transmission losses obtained from two curves using: )/log(/)/log()(21 infsupinfo
36、rinfsupinfhhhhLLLL += dB (5) where: h1, h2: the antenna heights above mean sea level for which the prediction is required (m) hinf: the nearest nominal effective height below h1 or 2hsup: the nearest nominal effective height above h1 or 2Linf: transmission loss value for hinfat the required distance
37、 Lsup: transmission loss value for hsupat the required distance. 4 Interpolation of transmission loss as a function of distance Unless d coincides with one of the distances given in the tabulated values, the transmission loss, should be linearly interpolated for the logarithm of the distance using:
38、)/log(/)/log()(infsupinfinfsupinfddddLLLL += dB (6) where: d : distance for which the prediction is required (km) dinf: nearest tabulation distance less than d dsup: nearest tabulation distance greater than d Linf: transmission loss value for dinfLsup: transmission loss value for dsup.5 Interpolatio
39、n of transmission loss as a function of frequency If the frequency for the prediction is not one of the frequencies represented in the figures of this Recommendation or in the tabulated data, the required transmission loss should be calculated using: )/log(/)/log()(infsupinfinfsupinfffffLLLL += dB (
40、7) where: f : frequency for which the prediction is required (MHz) finf: lower nominal frequency fsup: higher nominal frequency Linf: transmission loss value for finfLsup: transmission loss value for fsup. Rec. ITU-R P.528-3 5 6 Interpolation of transmission loss as a function of percentage time Tra
41、nsmission loss values for a given percentage of time should be calculated by interpolation using: )/()()/()(supinfsuptinfsupinftinfsupQQQQLQQQQLL += dB (8) where: t : percentage time for which the prediction is required tinf: lower nominal percentage time tsup: upper nominal percentage time Qt= Qi(t
42、/100) Qinf= Qi(tinf /100) Qsup= Qi(tsup /100) Linf: transmission loss value for time percentage tinfLsup:transmission loss value for time percentage tsupwhere Qi(x) is the inverse complementary cumulative normal distribution function described in 7. 7 An approximation to the inverse complementary cu
43、mulative normal distribution function The following approximation to the inverse complementary cumulative normal distribution function, Qi(x), is valid for 0.01 x 0.99: )()()( xxTxQi= if x 0.5 (9a) )1()1()( xxTxQi= if x 0.5 (9b) where: )ln(2)( xxT = (9c) 1)()()()()(=)(123012+xTDxTDxTDCxTCxTCx(9d) C0
44、= 2.515517 C1= 0.802853 C2= 0.010328 D1= 1.432788 D2= 0.189269 D3= 0.001308 Values given by the above equations are given in Table 1. 6 Rec. ITU-R P.528-3 TABLE 1 Approximate inverse complementary cumulative normal distribution values q% Qi (q/100) q% Qi (q/100) q% Qi (q/100) q% Qi (q/100) 1 2.327 2
45、6 0.643 51 0.025 76 0.706 2 2.054 27 0.612 52 0.050 77 0.739 3 1.881 28 0.582 53 0.075 78 0.772 4 1.751 29 0.553 54 0.100 79 0.806 5 1.645 30 0.524 55 0.125 80 0.841 6 1.555 31 0.495 56 0.151 81 0.878 7 1.476 32 0.467 57 0.176 82 0.915 8 1.405 33 0.439 58 0.202 83 0.954 9 1.341 34 0.412 59 0.227 84
46、0.994 10 1.282 35 0.385 60 0.253 85 1.036 11 1.227 36 0.358 61 0.279 86 1.080 12 1.175 37 0.331 62 0.305 87 1.126 13 1.126 38 0.305 63 0.331 88 1.175 14 1.080 39 0.279 64 0.358 89 1.227 15 1.036 40 0.253 65 0.385 90 1.282 16 0.994 41 0.227 66 0.412 91 1.341 17 0.954 42 0.202 67 0.439 92 1.405 18 0.9
47、15 43 0.176 68 0.467 93 1.476 19 0.878 44 0.151 69 0.495 94 1.555 20 0.841 45 0.125 70 0.524 95 1.645 21 0.806 46 0.100 71 0.553 96 1.751 22 0.772 47 0.075 72 0.582 97 1.881 23 0.739 48 0.050 73 0.612 98 2.054 24 0.706 49 0.025 74 0.643 99 2.327 25 0.674 50 0.000 75 0.674 8 Procedure for interpolati
48、ng the values in this Recommendation The step-by-step procedure given below is intended to be applied to values derived from the field strength versus distance tables available from the Radiocommunication Bureau. They may, however, also be applied to values obtained from the curves. Step 1: For any
49、given percentage of time determine two nominal time percentages as follows: record the nearest nominal time percentage below the wanted time percentage (this is the lower nominal value, tinf); record the nearest nominal time percentage above the wanted time percentage (this is the higher nominal value, tsup). Rec. ITU-R P.528-3 7 If the required percentage of time is equal to 1%, 5%, 10%, 50%, or 95%, this value should
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