Technical Provisions for Mode S Services and Extended Squitter

More documents

Recommendations

Info

C-56 Technical Provisions for Mode S Services and Extended Squitter decode resulting from the most recently received Position Message shall be checked to be identical to within 5 meters for an airborne decode and 1.25 meters for a surface decode.. If the two positions are not identical to within this tolerance, the validation is failed and the initial Globally Unambiguous CPR decode under validation shall be discarded and the track shall be reinitialized. Note.— The position obtained from the initial global CPR decode is subsequently updated using local CPR decoding, until an independent ”odd” and “even” Position Message pair has been received. When this occurs, a second global CPR decode is performed. The resulting position is compared to the position update obtained from the local CPR decode using the most recently received Position Message. These two positions should agree since they are computed from the same message. C.2.6.10.3 Reasonableness Test Applied to Position Determined from Locally Unambiguous Decoding A reasonableness test shall be applied to a position computed using the Locally Unambiguous CPR decoding per §C.2.6.5 for Airborne, TIS-B or Intent Participants, or per §C.2.6.6 for Surface Participants. Upon receipt of the “even” or “odd” encoded Position Message that completes the Locally Unambiguous CPR decode, the receiver shall perform a reasonableness test on the most recently received position decode by performing the following test: If the difference between the TOMRs of the previously received Position Message and the most recently received Position Message is 30 seconds or less, and the difference in the reported position in the most recently received Position Message is greater than or equal to X NM, where: X=6 for Airborne Participants receiving Airborne Position Messages, or X=2.5 for Airborne Participants that have received a Surface Position Message, or X=2.5 for Surface Participants that have received an Airborne Position Message, or X=0.75 for Surface Participants receiving Surface Position Messages, then the validation shall be considered failed, and: 1) the most recently received position shall not be used to update the track, and 2) the received position shall be used to initiate or update a candidate duplicate address track or update a duplicate address track in accordance with §C.2.6.10.4. Notes.— DRAFT - Working Paper ASP TSGWP11-01 for review by the TSG during the meeting in June 2011 in Paris Draft 1. If no duplicate address or candidate duplicate address Report exists for this ICAO 24-bit address, the position message is used to initiate a candidate duplicate address Report. If a candidate duplicate address Report exists, the position message is used to update the candidate duplicate address Report. Otherwise, the position message is used to update the duplicate address Report unless the position message fails this validation test (see §C.2.6.10.4). 2. The position threshold value is based on the assumption of a maximum aircraft velocity of V knots (where V=600 for Airborne and V=50 for Surface) over a maximum time period of 30 seconds. This yields a maximum positional difference of approximately 5 NM for Airborne, and 0.5 NM for Surface. An additional measure of 1 NM for Airborne, and 0.25 NM for Surface are added to account for additional ADS-B positional measurement uncertainty. The position threshold of 2.5 nautical miles between surface and airborne participants was derived from the assumption of 250 knots maximum speed for a target transitioning from the surface state to an airborne state over 30 seconds, yielding approximately 2 nautical miles, with an additional 0.5 NM being added to allow for positional errors. C.2.6.10.4 Duplicate Address Processing The ICAO 24-bit address transmitted in each ADS-B Message and the derived Address Qualifier is used to identify and associate the messages for a particular aircraft/vehicle. Though each aircraft/vehicle should have a unique ICAO 24-bit address, there may be occasions on which more than one aircraft/vehicle is transmitting the same ICAO 24 bit address. It is important for ADS-B applications that receive 1090ES ADS- DRAFT - Working Paper ASP TSGWP11-01 for review by the TSG during the meeting in June 2011 in Paris
Appendix C C-57 B Reports to have knowledge of aircraft within receiving range. The requirements in the following subparagraphs enable detection of a duplicate address aircraft/vehicle when horizontal position separation is outside of the local CPR reasonableness test criteria of §C.2.6.10.3. Notes.— 1. Without duplicate address detection, an aircraft/vehicle that enters the range of the receiver with the same ICAO 24-bit address as that of an existing ADS-B Report would go undetected and message data from the undetected aircraft/vehicle could be erroneously associated with the existing ADS-B Report. 2. Duplicate Address processing is not required for TIS-B targets. The assumption is that the ADS-B Ground Stations will protect against any Duplicate Address situation. C.2.6.10.4.1 Candidate Duplicate Address Report A candidate duplicate address Report shall be initiated when a position message is received for an ICAO 24bit address that fails the local CPR reasonableness test validation of §C.2.6.10.3 and no candidate duplicate address Report or duplicate address Report is currently active for the received ICAO 24-bit address. If initiated, the candidate duplicate address Report is set to Initialization State as per RTCA DO-260B, §2.2.10.2 and the position message is stored for this candidate duplicate address Report. The ADS-B Report for which the position message did not pass the validation test of §C.2.6.10.3, the local CPR reasonableness test, is the primary ADS-B Report for this ICAO 24-bit address. Once a candidate duplicate address Report is initiated, association of subsequent position messages with this ICAO 24-bit address shall be first attempted on the primary ADS-B Report for this ICAO 24-bit address. If the position message does not pass the validation test of §C.2.6.10.3 on the primary ADS-B Report, the position message shall be used to attempt Track Initialization on the candidate duplicate address Report as per RTCA DO-260B, §2.2.10.2. Notes.— 1. TIS-B Reports and ADS-R Reports are separate and distinct from ADS-B Reports as per §C.3 and §C.4, so there is no duplicate address issues between these Report types and ADS-B Reports. 2. Inter-source correlation is addressed in RTCA DO-317. Draft C.2.6.10.4.2 Duplicate Address Condition A duplicate address condition shall be declared for an ICAO 24-bit address when a global CPR decode is completed by the receipt of both an even and odd position message within 10 seconds for the candidate duplicate address and passes the global CPR reasonableness test. Once declared, a duplicate address condition shall result in the Duplicate Address Flag in the State Vector Report set to “ON” in the ADS-B Report upon output of either ADS-B Report in the duplicate address condition. ADS-B Position Messages shall be associated with the ADS-B Report in the duplicate address condition that passes the local CPR reasonableness test in §C.2.6.10.3. Each ADS-B Report in the duplicate address condition shall be updated upon receipt of other Extended Squitter Messages containing the duplicate ICAO 24-bit address since there is no means to associate these messages with the correct aircraft. ADS-B Position, Velocity, Aircraft Identification and Category and Emergency / Priority Status (Subtype=1) Messages from aircraft/vehicles with ICAO 24-bit addresses identified as Duplicate Addresses shall be processed as Version ZERO (0) format Messages. Since Target State and Status Messages can be associated with the appropriate MOPS Version Number based on the Subtype, and Operational Status Messages contain the MOPS Version Number, these messages can be decoded directly. Notes.— DRAFT - Working Paper ASP TSGWP11-01 for review by the TSG during the meeting in June 2011 in Paris 1. The Duplicate Address Flag is used to indicate to ADS-B applications that information associated with that address can not be correctly associated with either ADS-B Report in the duplicate address condition. Additionally, the correct MOPS Version Number for each of the aircraft/vehicles can not be readily determined so interpretation of message data defaults to Version ZERO (0). 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:
Page 191 and 192:
Page 193 and 194: Appendix C C-5 Table C-2. “TYPE
Page 195 and 196: DRAFT - Working Paper ASP TSGWP11-0
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 and 240: Appendix C C-51 3. The decoded posi
Page 243: DRAFT - Working Paper ASP TSGWP11-0
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 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

Create successful ePaper yourself

Delete template?

Save as template?