Technical Provisions for Mode S Services and Extended Squitter

More documents

Recommendations

Info

DRAFT - Working Paper ASP TSGWP11-01 for review by the TSG during the meeting in June 2011 in Paris C-52 Technical Provisions for Mode S Services and Extended Squitter b. Compute the latitude index: j = ⎛ 59⋅ YZ0 − 60⋅ YZ ⎜ ⎝ 2 floor 17 1 1 ⎞ + ⎟ 2 ⎠ c. Compute the values of Rlat0 and Rlat1 using the following equation: Rlat i ⎛ YZ = Dlati ⋅⎜ MOD 17 ⎝ ⎞ i ( j, 60 − i) + ⎟ 2 ⎠ Southern hemisphere values of Rlati shall fall in the range from 270° to 360°. Subtract 360° from such values, thereby restoring Rlati to the range from −90° to +90°. d. If NL(Rlat0) is not equal to NL(Rlat1) then the two positions straddle a transition latitude—thus a solution for global longitude is not possible. Wait for positions where they are equal. Note 3.— When performing the NL function, the encoding process must ensure that the NL value is established in accordance with Note 5 of §C.2.6.2.d. This is more important in the Global Unambiguous Decode because large longitude errors are induced if the decode function is not selecting the NL value properly as discussed in Note 5 of §C.2.6.2.d. e. If NL(Rlat0) is equal to NL(Rlat1) then proceed with computation of Dloni, according to whether the most recently received Airborne Position Message was encoded with the even format (i = 0) or the odd format (i = 1) : Dlon i = 360° n i where n i = greater of NL(Rlat i) − i f. Compute m, the longitude index: , ⎛ XZ ⎜ ⎝ ⋅ [ ] and 1. ( NL −1) − XZ1 ⋅ NL 1 ⎞ + ⎟ 2 ⎠ Draft 0 m = floor , 17 where NL NL( Rlat ) 2 = i . g. Compute the global longitude, Rlon0 or Rlon1, according to whether the most recently received Airborne Position Message was encoded using the even format (that is, with i = 0) or the odd format (i = 1): ⎛ Rloni = Dloni ⋅ ⎜ MOD m,ni ⎝ ⎞ ( )+ XZi 2 17 ⎟ , ⎠ [ ] and 1. where n i = greater of NL(Rlat i) − i h. A reasonableness test shall be applied to the resulting decoded position in accordance with §C.2.6.10.2. C.2.6.8 GLOBALLY UNAMBIGUOUS CPR DECODING OF SURFACE POSITION This algorithm shall utilize one CPR surface position encoded “even” format message together with one CPR surface position encoded “odd” format message, to regenerate the geographic position of the aircraft or target. DRAFT - Working Paper ASP TSGWP11-01 for review by the TSG during the meeting in June 2011 in Paris
DRAFT - Working Paper ASP TSGWP11-01 for review by the TSG during the meeting in June 2011 in Paris Appendix C C-53 As surface-format messages are initially received from a particular aircraft, if there is no prior history of this aircraft, then a global decode shall be performed using “even” and “odd” format receptions, as described in this section. Note 1.— If the aircraft has been transmitting airborne format messages and their receptions were intrack, then it is not necessary to use even-odd decoding. Beginning with the first individual Surface Position Message reception, the location can be decoded using the local-decode technique, based on the previous target location as the reference. Note 2.— Even if the aircraft is appearing for the first time in surface format receptions, any single message could be decoded by itself into multiple locations, one being the correct location of the transmitting aircraft, and all of the others being separated by 90 NM or more from the correct location. Therefore, if it were known that the transmitting aircraft cannot be farther away than 45 NM from a known location, then the first received message could be decoded using the locally unambiguous decoding method described in §C.2.6.6. Under some circumstances it may be possible for an aircraft to be first detected when it is transmitting Surface Position Messages farther than 45 NM away from the receiving station. For this reason, even-odd decoding is required when messages are initially received from a particular aircraft. After this initial decode, as subsequent messages are received, they can be decoded individually (without using the even-odd technique), provided that the intervening time is not excessive. This subsequent decoding is based on the fact that the aircraft location has not changed by more than 45 NM between each new reception and the previously decoded location. The even-odd decoding process shall begin by identifying a pair of receptions, one in the “even” format, the other in the “odd” format, and whose separation in time does not exceed the time interval of X seconds, where X=50 seconds, unless the Ground Speed in either Surface Position Message is greater than 25 knots, or is unknown, in which cases X=25 seconds. Note 3.— The limit of 25 seconds is based on the possible change of location within this time interval. Detailed analysis of CPR indicates that if the change of location is 0.75 NM or less, then the decoding will yield the correct location of the aircraft. To assure that the change of location is actually no larger, and considering the maximum aircraft speed of 100 knots specified for the transmission of the surface format, the combination indicates that 25 seconds will provide the needed assurance. For targets on the airport surface when speeds are much less and the transmission rate is as low as one per 5 seconds, the corresponding time limit is 50 seconds. Given a CPR 17-bit surface position encoded in the “even” format (XZ0, YZ0) and another encoded in the “odd” format (XZ1, YZ1), separated by no more than X seconds, the algorithm shall regenerate the geographic position (latitude Rlat, and longitude Rlon) of the aircraft or target by performing the following sequence of steps: Draft a. Compute the latitude zone sizes Dlat 0 and Dlat 1 from the equation: Dlati = 90° 60 − i b. Compute the latitude index: ⎛ 59 ⋅YZo − 60YZ1 1 ⎞ j = floor⎜ + ⎟ 17 ⎝ 2 2 ⎠ c. Latitude. The following formulas will yield two mathematical solutions for latitude (for each value of i), one in the northern hemisphere and the other in the southern hemisphere. Compute the northern hemisphere solution of Rlat 0 and Rlat 1 using the following equation: ⎛ Rlati = Dlati⎜ MOD j,60−i ⎝ ( )+ YZi 2 17 DRAFT - Working Paper ASP TSGWP11-01 for review by the TSG during the meeting in June 2011 in Paris ⎞ ⎟ ⎠
Page 1 and 2:
DRAFT - Working Paper ASP TSGWP11-0
Page 3 and 4:
Page 5 and 6:
Page 7 and 8:
Page 9 and 10:
Page 11 and 12:
Page 13 and 14:
Page 15 and 16:
Page 17 and 18:
Page 19 and 20:
Page 21 and 22:
Page 23 and 24:
Page 25 and 26:
Page 27 and 28:
Page 29 and 30:
Page 31 and 32:
Appendix A A-7 TYPE Code Format Hor
Page 33 and 34:
Page 35 and 36:
Page 37 and 38:
Appendix A A-13 The supersonic vers
Page 39 and 40:
Appendix A A-15 The transponder sha
Page 41 and 42:
Page 43 and 44:
Page 45 and 46:
Page 47 and 48:
Page 49 and 50:
Page 51 and 52:
Page 53 and 54:
Page 55 and 56:
Page 57 and 58:
Page 59 and 60:
Page 61 and 62:
Page 63 and 64:
Page 65 and 66:
Appendix A A-41 MB FIELD DRAFT - Wo
Page 67 and 68:
Appendix A A-43 MB FIELD 1 MSB TRAN
Page 69 and 70:
Page 71 and 72:
Appendix A A-47 MB FIELD 1 2 3 4 5
Page 73 and 74:
Page 75 and 76:
Page 77 and 78:
Page 79 and 80:
Appendix A A-55 MB FIELD 1 BDS A,8
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Appendix A A-97 a) the PI sends a T
Page 123 and 124:
Appendix A A-99 This subfield shall
Page 125 and 126:
Appendix A A-101 These channels hav
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Appendix A A-109 A.4. MODE S BROADC
Page 135 and 136:
Appendix A A-111 Note 1.— This st
Page 137 and 138:
Page 139 and 140:
Appendix B B-3 TYPE code Subtype co
Page 141 and 142:
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
Page 153 and 154:
Appendix B B-17 Coding (Binary) (De
Page 155 and 156:
Appendix B B-19 a) ACAS operational
Page 157 and 158:
Appendix B B-21 Subfield Coding: DR
Page 159 and 160:
Appendix B B-23 Coding (Binary) (De
Page 161 and 162:
Page 163 and 164:
Page 165 and 166:
Page 167 and 168:
Page 169 and 170:
Appendix B B-33 MB FIELD DRAFT - Wo
Page 171 and 172:
Page 173 and 174:
Page 175 and 176:
Page 177 and 178:
Appendix B B-41 CF value ICAO/Mode
Page 179 and 180:
Page 181 and 182:
Page 183 and 184:
Page 185 and 186:
Page 187 and 188:
Page 189 and 190: DRAFT - Working Paper ASP TSGWP11-0
Page 193 and 194: Appendix C C-5 Table C-2. “TYPE
Page 199 and 200: Appendix C C-11 C.2.3.2.2 Time Sync
Page 213 and 214: Appendix C C-25 Notes.— DRAFT - W
Page 219 and 220: Msg Bit # “ME” Bit # Appendix C
Page 221 and 222: Appendix C C-33 Msg Bit # "ME” Bi
Page 231 and 232: Appendix C C-43 Notes. — DRAFT -
Page 239: Appendix C C-51 3. The decoded posi
Page 245 and 246: Appendix C C-57 B Reports to have k
Page 247 and 248: Appendix C C-59 Register 0516 DRAFT
Page 253 and 254: Appendix C C-65 Register 0A16 Figur
Page 259 and 260: Appendix C C-71 Table C-37. CF Fiel
Page 287 and 288: Appendix CD CD-3 ACTIONS EVENTS DRA
Page 291 and 292:
Appendix CD CD-7 too many broadcast
Page 293 and 294:
Page 295 and 296:
Page 297 and 298:
Appendix CD CD-13 CD.2.4.4.1.2 Poss
Page 299 and 300:
Appendix CD CD-15 D.2.4.4.2.1.2 A32
Page 301 and 302:
Appendix CD CD-17 AP/FD mode V/S-FP
Page 303 and 304:
Page 305 and 306:
Page 307 and 308:
Appendix CD CD-23 CD.2.4.7.5 BINARY
Page 309 and 310:
Page 311 and 312:
Appendix CD CD-27 Zone no. DRAFT -
Page 313 and 314:
Page 315 and 316:
Appendix CD CD-31 CD.4 IMPLEMENTATI
Page 317 and 318:
Page 319 and 320:
Page 321 and 322:
Page 323 and 324:
Page 325 and 326:
Appendix DE DE-7 c. for GNSS, the p
Page 327 and 328:
Appendix DE DE-9 MB FIELD DRAFT - W
Page 329 and 330:
Appendix DE DE-11 MB FIELD DRAFT -
show all

Technical Provisions for Mode S Services and Extended Squitter

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?