38:
1034:
979:
631:
857:
829:
529:
847:, which is an integer between 0 and 9. The calculated number can be less than 0 or more than 9, but in those cases either 0 or 9 is used instead. The formula for cutting off the calculated value of
1139:
648 000 is the number of arc seconds in a half circle, so a value greater than 9 would be meaningless as we would have no idea where the object will be in 10 years within the orbit.
434:
vs. optical), and the geometry of the observations. Of these parameters, the time spanned by the observations generally has the greatest effect on the orbital uncertainty.
788:
664:
755:
723:
694:
517:
1442:
Desmars, Josselin; Bancelin, David; Hestroffer, Daniel; Thuillot, William (Jun 2011). Alecian, G.; Belkacem, K.; Samadi, R.; Valls-Gabaud, D. (eds.).
974:{\displaystyle U=\min \left\{~9,~\max {\Bigl \{}\;0,\;\left\lfloor 9\cdot {\frac {\log r}{\;\log 648{,}000\;}}\right\rfloor +1\;{\Bigr \}}~\right\}}
126:
448:
Objects with a āDā have only been observed for a single opposition, and have been assigned two (or more) different designations ("double").
626:{\displaystyle r=\left(\Delta \tau \cdot e+10\cdot {\frac {\;\Delta P\;}{P}}\right)\cdot 3600\cdot 3\cdot {\frac {\;k_{\text{o}}\;}{P}}}
794:
1428:
1361:
1214:
1185:
1163:
832:
523:
per decade is calculated, (i.e. the discrepancy between the observed and calculated position extrapolated over ten years):
1382:
105:
437:
Occasionally, the Minor Planet Center substitutes a letter-code (āDā, āEā, āFā) for the uncertainty parameter.
520:
65:
1416:
463:
with a condition code āEā in the place of a numeric uncertainty parameter denotes orbits for which the listed
80:
after 10 years. The larger the number, the larger the uncertainty. The uncertainty parameter is also known as
1269:
85:
31:
1275:(Report). The Minor Planet Circulars / Minor Planets and Comets. 1995-02-15. p. 24597. MPC 24597ā24780
172:
37:
1486:
1451:
1244:
985:
698:
464:
334:
1424:
1357:
1210:
1181:
1159:
419:
198:
61:
42:
766:
646:
470:
was assumed, rather than determined. Objects with assumed eccentricities are generally considered
357:
311:
377:
1177:
988:
technically has an uncertainty of around −2.6, but is instead displayed as the minimal 0.
288:
1353:
265:
238:
218:
737:
93:
73:
46:
1324:
253:
1033:
995:
for the logarithm, so long as the same logarithm is used throughout the formula; e.g. for "
1481:
431:
427:
843:
Then, the obtained in-orbit longitude runoff is converted to the "uncertainty parameter"
76:
from 0 to 9 that measures the anticipated longitudinal uncertainty in the minor planet's
1455:
1206:
1155:
727:
708:
679:
502:
474:
if they have not recently been observed because their orbits are not well constrained.
17:
1475:
471:
92:
value should not be used as a predictor for the uncertainty in the future motion of
212:
77:
69:
1298:
1240:
423:
232:
1394:
669:
1448:
SF2A 2011: Annual
Meeting of the French Society of Astronomy and Astrophysics
1030:
remains the same if the logarithm is the same in both places in the formula.
992:
186:
499:
parameter is calculated in two steps. First the in-orbit longitude runoff
113:
371:
49:. However, large numbers of smaller NEAs have highly uncertain orbits.
1325:"Definition / description for SBDB parameter / field: condition code"
1299:
Strategic implications of human exploration of near-Earth asteroids
1443:
1032:
167:
36:
1444:"Statistical analysis on the uncertainty of asteroid ephemerides"
418:
Orbital uncertainty is related to several parameters used in the
1386:
1302:
1248:
824:{\displaystyle 0.01720209895\cdot {\frac {180^{\circ }}{\pi }}}
1390:
482:
Objects with an āFā fall in both categories āDā and āEā.
1292:
1290:
426:(measurements), the time spanned by those observations (
30:
For the quantification of uncertainty in general, see
1085:
19.6 arc seconds – 1.4 arc minutes
860:
797:
769:
740:
711:
682:
649:
532:
505:
991:The result is the same regardless of the choice of
973:
823:
782:
749:
717:
688:
658:
625:
511:
1383:"Near-Earth objects close-approach uncertainties"
1201:
1199:
1197:
1195:
958:
892:
45:are generally well known, though a few have been
887:
867:
404:ccentricity was guessed instead of determined.
27:Parameter introduced by the Minor Planet Center
1348:
1346:
1344:
1342:
8:
1247:. Mission Design Center Trajectory Browser.
1235:
1233:
1231:
984:For instance: As of 10 September 2016,
1040:
955:
940:
930:
904:
897:
759:uncertainty in the orbital period in days
616:
605:
575:
568:
392:ata insufficient for orbit determination.
103:
957:
956:
916:
891:
890:
859:
810:
804:
796:
774:
768:
739:
710:
681:
648:
610:
602:
565:
531:
504:
430:), the quality of the observations (e.g.
1385:. JPL Near-Earth Object Program Office.
1156:"Orbits for Near Earth Asteroids (NEAs)"
1354:"Export format for minor-planet orbits"
1147:
411:
399:
387:
64:(MPC) to quantify the uncertainty of a
7:
1301:(Report). NASA Technical Reports.
741:
650:
569:
544:
25:
1109:28 arc minutes – 2.1Ā°
1429:International Astronomical Union
1393:. 31 August 2005. Archived from
1362:International Astronomical Union
1215:International Astronomical Union
1186:International Astronomical Union
1164:International Astronomical Union
1077:4.4–19.6 arc seconds
422:process including the number of
1241:"Trajectory Browser User Guide"
1093:1.4–6.4 arc minutes
1069:1.0–4.4 arc seconds
833:Gaussian gravitational constant
412: Both āDā and āEā apply.
1101:6.4–28 arc minutes
1061:< 1.0 arc second
41:The orbits of kilometre class
1:
106:Classical Kuiper belt objects
1053:Longitude runoff per decade
783:{\displaystyle k_{\text{o}}}
659:{\displaystyle \Delta \tau }
1327:. JPL Solar System Dynamics
1207:"Uncertainty parameter 'U'"
86:Small-Body Database Browser
1503:
1450:. Paris, France: 639ā642.
370:
347:
324:
301:
278:
251:
231:
211:
184:
166:
29:
1050:
1045:
138:(millions of kilometers)
1026:the calculated value of
750:{\displaystyle \Delta P}
701:of the determined orbit
1297:Drake, Bret G. (2011).
835:, converted to degrees
68:orbital solution for a
32:Measurement uncertainty
18:Uncertainty Parameter U
1038:
975:
825:
784:
751:
719:
690:
660:
627:
513:
108:40ā50 AU from the Sun
50:
1036:
976:
826:
785:
752:
720:
691:
661:
628:
514:
135:distance from the Sun
72:. The parameter is a
60:is introduced by the
55:uncertainty parameter
40:
1245:Ames Research Center
858:
795:
767:
738:
709:
680:
647:
530:
503:
1456:2011sf2a.conf..639D
1425:Minor Planet Center
1358:Minor Planet Center
1211:Minor Planet Center
1182:Minor Planet Center
1178:"M.P. Orbit Format"
1160:Minor Planet Center
1042:
1037:Function graph U(r)
668:uncertainty in the
420:orbit determination
109:
100:Orbital uncertainty
62:Minor Planet Center
1041:
1039:
971:
821:
780:
747:
715:
686:
656:
623:
509:
156:Table setting: 39
104:
94:near-Earth objects
51:
1137:
1136:
965:
942:
886:
877:
839:
838:
819:
777:
718:{\displaystyle P}
689:{\displaystyle e}
621:
613:
580:
512:{\displaystyle r}
486:
485:
416:
415:
380:
360:
337:
314:
291:
268:
241:
221:
201:
74:logarithmic scale
16:(Redirected from
1494:
1467:
1466:
1464:
1462:
1439:
1433:
1432:
1413:
1407:
1406:
1404:
1402:
1397:on 24 March 2004
1379:
1373:
1372:
1370:
1368:
1350:
1337:
1336:
1334:
1332:
1321:
1315:
1314:
1312:
1310:
1294:
1285:
1284:
1282:
1280:
1274:
1270:Editorial Notice
1266:
1260:
1259:
1257:
1255:
1237:
1226:
1225:
1223:
1221:
1203:
1190:
1189:
1174:
1172:
1170:
1152:
1117:2.1Ā°–9.2Ā°
1048:
1043:
1029:
1025:
1018:
1014:
1005:
998:
980:
978:
977:
972:
970:
966:
963:
962:
961:
948:
944:
943:
941:
928:
917:
896:
895:
884:
875:
850:
846:
830:
828:
827:
822:
820:
815:
814:
805:
789:
787:
786:
781:
779:
778:
775:
756:
754:
753:
748:
724:
722:
721:
716:
695:
693:
692:
687:
665:
663:
662:
657:
641:
640:
632:
630:
629:
624:
622:
617:
615:
614:
611:
603:
586:
582:
581:
576:
566:
518:
516:
515:
510:
462:
456:Objects such as
445:D
442:
441:
376:
356:
353:
333:
330:
310:
307:
287:
284:
280:(160256) 2002 PD
264:
261:
259:
258:
237:
217:
197:
194:
192:
191:
110:
21:
1502:
1501:
1497:
1496:
1495:
1493:
1492:
1491:
1472:
1471:
1470:
1460:
1458:
1441:
1440:
1436:
1420:
1415:
1414:
1410:
1400:
1398:
1381:
1380:
1376:
1366:
1364:
1352:
1351:
1340:
1330:
1328:
1323:
1322:
1318:
1308:
1306:
1296:
1295:
1288:
1278:
1276:
1272:
1268:
1267:
1263:
1253:
1251:
1239:
1238:
1229:
1219:
1217:
1205:
1204:
1193:
1176:
1168:
1166:
1154:
1153:
1149:
1145:
1125:9.2Ā°–41Ā°
1052:
1046:
1027:
1024:
1020:
1016:
1013:
1007:
1004:
1000:
996:
929:
918:
909:
905:
874:
870:
856:
855:
848:
844:
806:
793:
792:
770:
765:
764:
736:
735:
707:
706:
678:
677:
645:
644:
606:
604:
567:
543:
539:
528:
527:
501:
500:
493:
461:
457:
428:observation arc
352:
348:
329:
325:
306:
302:
283:
279:
256:
255:
254:(15807) 1994 GV
252:
189:
188:
185:
155:
153:
150:
144:
137:
134:
131:
129:
122:
119:
116:
102:
35:
28:
23:
22:
15:
12:
11:
5:
1500:
1498:
1490:
1489:
1484:
1474:
1473:
1469:
1468:
1434:
1418:
1408:
1374:
1338:
1316:
1305:. 2011-0020788
1286:
1261:
1227:
1191:
1146:
1144:
1141:
1135:
1134:
1133:> 41Ā°
1131:
1127:
1126:
1123:
1119:
1118:
1115:
1111:
1110:
1107:
1103:
1102:
1099:
1095:
1094:
1091:
1087:
1086:
1083:
1079:
1078:
1075:
1071:
1070:
1067:
1063:
1062:
1059:
1055:
1054:
1049:
1022:
1009:
1002:
982:
981:
969:
960:
954:
951:
947:
939:
936:
933:
927:
924:
921:
915:
912:
908:
903:
900:
894:
889:
883:
880:
873:
869:
866:
863:
841:
840:
837:
836:
818:
813:
809:
803:
800:
790:
773:
761:
760:
757:
746:
743:
732:
731:
728:orbital period
725:
714:
703:
702:
696:
685:
674:
673:
666:
655:
652:
634:
633:
620:
609:
601:
598:
595:
592:
589:
585:
579:
574:
571:
564:
561:
558:
555:
552:
549:
546:
542:
538:
535:
521:seconds of arc
508:
492:
489:
488:
487:
484:
483:
480:
476:
475:
459:
454:
450:
449:
446:
414:
413:
410:
406:
405:
398:
394:
393:
386:
382:
381:
374:
369:
366:
362:
361:
354:
350:
346:
343:
339:
338:
331:
327:
323:
320:
316:
315:
308:
304:
300:
297:
293:
292:
285:
281:
277:
274:
270:
269:
262:
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243:
242:
235:
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215:
210:
207:
203:
202:
195:
183:
180:
176:
175:
170:
168:(134340) Pluto
165:
162:
158:
157:
154:Location: @sun
146:
139:
133:Uncertainty in
124:
101:
98:
82:condition code
26:
24:
14:
13:
10:
9:
6:
4:
3:
2:
1499:
1488:
1485:
1483:
1480:
1479:
1477:
1457:
1453:
1449:
1445:
1438:
1435:
1430:
1426:
1422:
1412:
1409:
1396:
1392:
1388:
1384:
1378:
1375:
1363:
1359:
1355:
1349:
1347:
1345:
1343:
1339:
1326:
1320:
1317:
1304:
1300:
1293:
1291:
1287:
1271:
1265:
1262:
1250:
1246:
1242:
1236:
1234:
1232:
1228:
1216:
1212:
1208:
1202:
1200:
1198:
1196:
1192:
1187:
1183:
1179:
1165:
1161:
1157:
1151:
1148:
1142:
1140:
1132:
1129:
1128:
1124:
1121:
1120:
1116:
1113:
1112:
1108:
1105:
1104:
1100:
1097:
1096:
1092:
1089:
1088:
1084:
1081:
1080:
1076:
1073:
1072:
1068:
1065:
1064:
1060:
1057:
1056:
1044:
1035:
1031:
1012:
994:
989:
987:
967:
952:
949:
945:
937:
934:
931:
925:
922:
919:
913:
910:
906:
901:
898:
881:
878:
871:
864:
861:
854:
853:
852:
834:
816:
811:
807:
801:
799:0.01720209895
798:
791:
771:
763:
762:
758:
744:
734:
733:
729:
726:
712:
705:
704:
700:
697:
683:
676:
675:
672:time in days
671:
667:
653:
643:
642:
639:
638:
637:
618:
607:
599:
596:
593:
590:
587:
583:
577:
572:
562:
559:
556:
553:
550:
547:
540:
536:
533:
526:
525:
524:
522:
506:
498:
490:
481:
478:
477:
473:
469:
467:
455:
452:
451:
447:
444:
443:
440:
439:
438:
435:
433:
429:
425:
421:
408:
407:
403:
396:
395:
391:
384:
383:
379:
375:
373:
367:
364:
363:
359:
355:
344:
341:
340:
336:
332:
321:
318:
317:
313:
309:
298:
295:
294:
290:
286:
275:
272:
271:
267:
263:
260:
248:
245:
244:
240:
236:
234:
228:
225:
224:
220:
216:
214:
208:
205:
204:
200:
196:
193:
181:
178:
177:
174:
171:
169:
163:
160:
159:
152:
147:
143:
140:
136:
128:
125:
121:
115:
112:
111:
107:
99:
97:
95:
91:
87:
83:
79:
75:
71:
67:
63:
59:
56:
48:
44:
39:
33:
19:
1459:. Retrieved
1447:
1437:
1411:
1399:. Retrieved
1395:the original
1377:
1365:. Retrieved
1329:. Retrieved
1319:
1307:. Retrieved
1277:. Retrieved
1264:
1252:. Retrieved
1218:. Retrieved
1167:. Retrieved
1150:
1138:
1010:
990:
983:
842:
699:eccentricity
635:
496:
494:
465:
436:
424:observations
417:
401:
389:
213:20000 Varuna
148:
141:
132:
130:January 2018
117:
89:
81:
78:mean anomaly
70:minor planet
57:
54:
52:
1487:Measurement
1401:15 November
1331:15 November
1220:15 November
491:Calculation
468:ccentricity
233:19521 Chaos
118:Uncertainty
1476:Categories
1143:References
670:perihelion
935:
923:
914:⋅
817:π
812:∘
802:⋅
742:Δ
730:in years
654:τ
651:Δ
600:⋅
594:⋅
588:⋅
570:Δ
563:⋅
551:⋅
548:τ
545:Δ
173:E2022-J69
151:Ephemeris
149:Reference
120:parameter
84:in JPL's
66:perturbed
1417:"2003 UU
946:⌋
907:⌊
127:Horizons
114:JPL SBDB
1461:3 March
1452:Bibcode
1367:3 March
1309:3 March
1279:3 March
1254:3 March
1169:25 June
938:648,000
458:2003 UU
400:
388:
372:1995 GJ
368:Ā±1,600
349:1995 KJ
326:1999 CQ
303:1999 DH
187:2013 BL
145:
123:
1482:Orbits
1051:Runoff
964:
885:
876:
229:Ā±0.84
209:Ā±0.14
182:Ā±0.04
164:Ā±0.01
142:Object
88:. The
1273:(PDF)
1019:, or
986:Ceres
636:with
432:radar
345:Ā±590
322:Ā±190
276:Ā±8.2
249:Ā±1.4
1463:2016
1403:2011
1387:NASA
1369:2016
1333:2011
1311:2016
1303:NASA
1281:2016
1256:2016
1249:NASA
1222:2011
1175:via
1171:2020
999:" =
993:base
591:3600
495:The
472:lost
409:āFā
397:āEā
385:āDā
299:Ā±70
53:The
47:lost
43:NEAs
1419:291
1391:JPL
1021:log
1008:log
1001:log
997:log
932:log
920:log
888:max
868:min
851:is
808:180
519:in
460:291
378:JPL
358:JPL
335:JPL
328:153
312:JPL
289:JPL
282:149
266:JPL
239:JPL
219:JPL
199:JPL
1478::
1446:.
1427:.
1423:.
1389:/
1360:.
1356:.
1341:^
1289:^
1243:.
1230:^
1213:.
1209:.
1194:^
1184:.
1180:.
1162:.
1158:.
1130:9
1122:8
1114:7
1106:6
1098:5
1090:4
1082:3
1074:2
1066:1
1058:0
1017:ln
1015:,
1006:,
1003:10
831:,
560:10
479:F
453:E
365:9
342:8
319:7
296:6
273:5
246:4
226:3
206:2
190:76
179:1
161:0
96:.
1465:.
1454::
1431:.
1421:"
1405:.
1371:.
1335:.
1313:.
1283:.
1258:.
1224:.
1188:.
1173:.
1047:U
1028:U
1023:2
1011:e
968:}
959:}
953:1
950:+
926:r
911:9
902:,
899:0
893:{
882:,
879:9
872:{
865:=
862:U
849:U
845:U
776:o
772:k
745:P
713:P
684:e
619:P
612:o
608:k
597:3
584:)
578:P
573:P
557:+
554:e
541:(
537:=
534:r
507:r
497:U
466:e
402:E
390:D
351:1
305:8
257:9
90:U
58:U
34:.
20:)
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