0 - Technical description of solution iaa2008a.crf

 1 - Technique:   VLBI

 2 - Analysis Centre:
       IAA
     
 3 - Software used:
       QUASAR
     
 4 - Data span:
     Jan 1980 - Mar 2009
     6353387 observations total.

 5 - Celestial Reference Frame: ICRF-Ext2 

     a - Nature:
     
         extragalactic

     b - Definition of the orientation:
         no-net-rotation using 203 defining radio sources of the ICRF (see Appendix B).

 6 - Terrestrial Reference Frame: vtrf2008 and associated 
                                  vtrf2008 velocity field 
                                  
        
      Definition of the origin:
     
         No net translation condition for 11 stations in the TRF
         (KOKEE   , WETTZELL, WESTFORD, ALGOPARK, NYALES20, ONSALA60,
          LA-VLBA , MATERA  , FORTLEZA, NOTO    , MK-VLBA)

	 i.e. sum over all translations of these stations is zero.

      Definition of the orientation:
     
         No net rotation condition for 11 stations in the TRF
         (KOKEE   , WETTZELL, WESTFORD, ALGOPARK, NYALES20, ONSALA60,
          LA-VLBA , MATERA  , FORTLEZA, NOTO    , MK-VLBA)
	 i.e. sum over all rotations of these stations is zero.

       Reference epoch:
     
         2000.0

     Constraints for time evolution:
     
         No net velocity adjustment condition in translation 
         and rotation for 11 stations in the TRF 
         (KOKEE   , WETTZELL, WESTFORD, ALGOPARK, NYALES20, ONSALA60,
          LA-VLBA , MATERA  , FORTLEZA, NOTO    , MK-VLBA)
        i.e. sum over all velocities adjustments in translation 
         and rotation of these stations TRF is zero.
         
     VLBI antenna axis offsets:      
     
       The values of VLBI antenna axis offsets were taken from official IVS list.


 7 - Earth orientation:

     a - A priori precession model:
     
	IAU 2000A Precession-Nutation Model
         
     b - A priori nutation model:
     
	IAU 2000A Precession-Nutation Model

     c - Short-period tidal variations in x, y, UT1:

    IERS convention 2003 model

 8 - Estimated Parameters:

    a. celestial frame: right ascension, declination (global)
 
    b. terrestrial frame:  X, Y, Z, Xdot, Ydot, Zdot (global)
 
    c. Earth orientation: Xp, Yp, UT1-TAI, Xc, Yc (local)
 
    d. zenith troposphere:   linear + stochastic signal (local).
 
    e. troposphere gradient: east and north (local)
 
    f. station clocks: quadratic (local) + stochastic signal (local).
 
 9 - Comments
 
   For coordinates of sources that observed lesser than 5 times the soft 10m constraint was applied.
   For velocities of station that operated less than in 5 session or time span less than 1 year
   the soft 10cm constraint was applied. (List of that sources and stations in Appendix A)

Appendix A:
Sources observed <5 times:
1020-103
0028-396
0142-398
3C343   
3C343.1 
2252+618
1109-567
2205-636
1540-828
1221-829
1215-457
2300-683
0833-450
1217+295
1345+061
1853-179
1855-252
0945-287
1740-190
1934-065
1917-386
2157-375
0604-004
1537-389
1258+145
1645-262
0557-182
0603+882
0822-243
0804-172
0907-179
0930-200
1119-044
1150-050
0920+313
1224+439
0930+396
1004+054
1204-267
1253-216
1347-163
1354-107
1536+057
1606-219
1630-107
1649+216
1628+071
1639-287
1701+016
1709-182
1732-059
2004-125
2020-122
2141+333
2122-148
2137+130
2156-013
2208+199
2245-091
2347+079
2337-234
2354-251
0158-141
0231+045
0256-256
0514+074
0515-179
0609-119
0701-130
0708-204
0835-339
2201+676
0548+689
2236+678
0238+711
0733+597
0753+519
1016+635
1238+702
1245+676
1532+680
1822+682
1902+556
1700+685
0035+503
0144+584
2003+662
2119+664
0758+594
0252-712
1117-248
0527-253
1205+545
1227+587
1250+532
1303+557
1312+533
1324+574
1550+582
1607+563
2046+535
0024+597
0200+539
0335+599
0601+578
0627+532
0702+612
0843+575
0900+520
1600+431
1256+802

Stations ((Nsess<5).or.(MJD_last-MJD_first<365)):
TSUKUB32
CTVASBAY
TIDBIN64
NRAO 140
CHLBOLTN
ROBLED32
MAMMOTHL
PVERDES 
DEADMANL
OCOTILLO
FLAGSTAF
NOME    
SOURDOGH
YAKATAGA
WHTHORSE
YELLOWKN
PENTICTN
VERNAL  
SEATTLE1
MIYAZAKI
AUSTINTX
CARROLGA
BERMUDA 
BLOOMIND
LEONRDOK
MILESMON
HALEAKAL
GOLDMARS
FTD 7900
FORTORDS
TSUKUBA 
GORF7102
HOHENFRG
METSHOVI
TROMSONO
CARNUSTY
BREST   
GRASSE  
NOBEY 6M
SEST    
VICTORIA
NOTOX   
MIZUSGSI
TOULOUSE
AZORES  
KIRSBERG
KARLBURG
HOFN    
MIAMI20 
WHTHOR87
MOJAVE92
PRESID89
YAKATA87
SOURDO87

Appendix B:
203 source for NNR constraints
1726+455
0133+476
0955+476
0718+792
1606+106
0804+499
2037+511
1219+044
2136+141
1418+546
1954-388
0642+449
0521-365
0256+075
1745+624
2000-330
0749+540
0805+410
1128+385
1057-797
0556+238
1954+513
2113+293
0917+624
0400+258
1600+335
1038+528
1849+670
1038+064
0636+680
0446+112
0202+319
1236+077
2052-474
0544+273
1130+009
2329-162
1856+737
1342+663
1221+809
0818-128
0457+024
2319+272
0829+046
0954+658
1624+416
2254+074
0952+179
1823+568
0239+108
0422+004
0306+102
0454+844
0745+241
0215+015
1039+811
2029+121
2320+506
2021+317
2209+236
0109+224
0820+560
0821+394
0743+259
0945+408
1150+497
1705+018
1150+812
2017+745
1416+067
0754+100
1226+373
1347+539
0707+476
1845+797
1725+044
0003+380
0833+585
2143-156
0131-522
0426-380
0629-418
0648-165
0342+147
1020+400
1213+350
1445-161
1604-333
2106-413
2329-384
1252+119
1324+224
0812+367
1538+149
0159+723
0507+179
0615+820
1215+303
0138-097
2059+034
1257+145
2229+695
0716+714
0723-008
0148+274
1504+377
0733-174
1030+415
1727+502
0859+470
1116+128
0917+449
1514+197
1616+063
0839+187
0722+145
0309+411
2030+547
0912+297
0458+138
1342+662
0422-380
1147+245
0826-373
1800+440
0530-727
0414-189
2008-068
0539-057
0537-286
0955+326
1032-199
1111+149
1706-174
1743+173
2204-540
2312-319
1637+574
2051+745
1751+441
1155+251
1459+480
2150+173
0440-003
1842+681
0039+230
1442+101
0502+049
1040+123
1435+638
0149+218
0302-623
0423+051
1148-671
0834-201
0406+121
2232-488
0437-454
1549-790
1012+232
0454-810
2326-477
0738-674
1758-651
1619-680
1143-245
0007+171
0047-579
0135-247
1532+016
0220-349
1049+215
1903-802
2146-783
0123+257
1830+285
0230-790
0506-612
2109-811
0516-621
2059-786
1718-649
0308-611
1251-713
1236-684
1216+487
1656+348
0828+493
0609+607
1749+701
0007+106
0010+405
1038+529
2048+312
1547+507
0153+744
0224+671
0248+430
0831+557
0219+428
0850+581
0538+498
0518+165