Delivered-To: igsmail@igscb.jpl.nasa.gov Message-ID: <5ACEEE96F4F9D41190790002A528B51E78E7C1@s0-ott-x11.nrcan.gc.ca> From: =?iso-8859-1?Q?=22Ferland=2C_R=E9mi=22?= To: "'igsmail@igscb.jpl.nasa.gov'" Subject: [IGSMAIL-4666]: IGS00 (v2) Final Date: Wed, 29 Oct 2003 09:25:45 -0500 Sender: owner-igsmail Precedence: bulk ****************************************************************************** IGS Electronic Mail 29 Oct 06:25:59 PST 2003 Message Number 4666 ****************************************************************************** Author: R. Ferland Dear colleagues, You have received on Oct 9, the proposed update to the IGS realization of ITRF2000. Following some suggestions/comments two minor changes were made: 1) The ordering of the parameters in the "IGS03P33_RS99.snx" was modified, so that the coordinates/velocity are all ordered in the usual manner. There is however no changes to the numerical values. 2) In the report (README file and included at the end) section 7, the formulas: (R X) - dXp =3D 0.011 mas (R Y) - dYp =3D -0.006 mas were incorrect. To be consistent with the convention, they should have been: (R X) - dYp =3D -0.007 mas (R Y) - dXp =3D 0.010 mas Fortunately, the differences are still well within the noise level so the conclusions are unchanged. Thanks to Jim Ray for pointing this out. A copy of the updated README file is attached. As before, five files are also available: README - Description of the analysis (Updated & attached) IGS00_v2_7.xls - An excel file used to summarize some statistics on several stations (some info may be out of date). IGS03P33_RS99.snx - A SINEX file containing the stations retained in this second iteration (Updated). Original_54.tiff - Stations distribution in the current IGS realization. proposed_99.tiff - Station distribution in the proposed IGS realization. You can find them at: ftp macs.geod.emr.ca cd /pub/requests/sinex/rfwg Unless something happens to stations in the proposed station list; this should conclude the final iteration for the version 2 of the proposed=20 realization of ITR2000. Thanks to all who contributed either directly with your comments, suggestions and tests, and also to all who have been contributing all your weekly SINEX solutions. Best Regards, Remi, R=E9mi Ferland rferland@NRCan.gc.ca, 613-995-4002, fascimile/t=E9l=E9copieur = 613-995-3215 Natural Resources Canada, 456-615 Booth Street, Ottawa, Ontario K1A 0E9 Ressources naturelles Canada, 456-615 rue Booth, Ottawa, Ontario K1A = 0E9 Government of Canada / Gouvernement du Canada README File: ------------ 1) Introduction After ITRF2000 was made available in early 2001, a realization of the frame was prepared using the cumulative solution from GPS week 1131 "IGS01P37.snx". It is referred below as IGS2000(v1). An important reason for doing this was to improve internal consistency. More about this can be found in: Kouba, J., J. Ray and M.M. Watkins, IGS Reference Frame Realization, 1998 IGS Analysis Center Workshop Proceedings, European Space Operations Centre, Darmstadt, Germany. For IGS2000(v1), a subset of "high quality" stations was agreed to within the reference frame working group. It originally included 54 stations and was implemented on GPS week 1143 (01/12/02). Since then, the number of usable stations for the reference frame realization has gradually decreased to about 45 stations. Suggestions were made last spring to improve the existing realization (namely from J.Ray, M. Heflin and G. Gendt) by increasing the number of stations. Those suggestions were combined. Several of those suggested were located in Europe and North America. Those two regions have already a good coverage. In an attempt to improve the global distribution, the selection effort I made, was mainly concentrated in locations with relatively sparse coverage. Altogether, close to 200 stations were considered, about half of them have passed all the selection process steps. The criterions used for the selections generally followed the in Kouba et al. (reference above). The selection criterions were also reiterated and expanded in: Ray, J.R., Reinforcing and securing the IGS Reference Tracking Network, .... As was the case in the past, few stations met equally well all the criterions listed in the above references.=20 During the iterations, some subjective decision making took place. If you find the selection of some stations unreasonable (excluding politics), the suggested set can certainly be adjusted. It was suggested that for some stations which did experience discontinuities, to use separately, the appropriate portion of the solution for the alignment and for the realization. This suggestion was implemented. In those cases, the velocity estimate for the segments was forced to be unique. This will cause some temporary side effects on the alignment of the cumulative solution which can easily be handled. The idea was also extended to split the stations contributing to the alignment to ITRF2000 and the stations forming the realization. Although most stations are common, this allowed to retain some remote stations that would otherwise have been rejected. Some stations had limited data available when ITRF2000 was made available about 2.5 years ago. Also, the=20 most recent data used in ITRF2000 to estimate the stations coordinates/velocity estimates is at least 3 years old. In some cases, this caused some occasional differences. After the alignment and realization processes, the magnitude of the discontinuity between the current and proposed realizations should be small, since both subsets were extracted from consistent solutions. 2) Review of some stations IGS2000(v1) BRMU Discontinuity last spring (Mar. 22). Suggest to drop it. DGAR Station performance is currently deficient. It is located in an isolated location. Suggest to keep it in. KERG Station has had occasional data problems. Suggest to keep it in. KWJ1 Station down since 02/11. No sign of change. Suggest to Drop it. LHAS Station has had some problems recently. Suggest to keep it in based on past performance. OHIG Off. Use OHI2. SHAO Station down since 02/10. No sign of change. Suggest to Drop it. THU1 Off. Use THU3 ZWEN No data since 03/03. No sign of change. Suggest to Drop it. 3) Suggested stations in the new realization IGS2000(v2) The proposed set currently includes 99 stations: ALGO ALIC ARTU ASC1 AUCK BAHR BILI BOR1 BRUS CAS1 CEDU CHAT CHUR COCO CRO1 DARW DAV1 DGAR DRAO DUBO EISL FAIR FLIN FORT GLSV GODE GOLD GOUG GRAS GRAZ GUAM HOB2 HOFN HRAO IISC IRKT JAB1 JOZE KARR KELY KERG KIT3 KOKB KOUR KSTU LAMA LHAS LPGS MAC1 MAG0 MALI MANA MAS1 MATE MAW1 MCM4 MDO1 MKEA NICO NKLG NLIB NOUM NRC1 NTUS NYAL OHI2 ONSA PERT PETP PIE1 POL2 POTS RBAY RIOG SANT SCH2 SFER STJO SYOG THTI THU3 TIDB TIXI TOW2 TRAB TRO1 TSKB UNSA URUM VESL VILL WES2 WSRT WTZR YAKT YAR1 YELL YSSK ZIMM 7 stations from IGS2000(v1) have not been retained in the proposed IGS2000(v2), Those are: BRMU KWJ1 OHIG SHAO THU1 TROM ZWEN Some solutions (OHIG -> OHI2 , THU1 -> THU3 , TROM -> TRO1 ) had alternative solution at the same site. There is 47 common stations between IGS2000(v1) and IGS2000(v2). They are: ALGO ASC1 AUCK BAHR CAS1 CEDU CHAT DAV1 DGAR DRAO FAIR FORT GODE GOLD GRAZ GUAM HOB2 HRAO IRKT KERG KIT3 KOKB KOUR LHAS LPGS MAC1 MALI MAS1 MATE MCM4 MDO1 NLIB NYAL ONSA PERT PIE1 POTS RIOG SANT TIDB TSKB VILL WES2 WSRT WTZR YAR1 YELL 52 new stations are in the proposed in IGS2000(v2): ALIC ARTU BILI BOR1 BRUS CHUR COCO CRO1 DARW DUBO EISL FLIN GLSV GOUG GRAS HOFN IISC JAB1 JOZE KARR KELY KSTU LAMA MAG0 MANA MAW1 MKEA NICO NKLG NOUM NRC1 NTUS OHI2 PETP POL2 RBAY SCH2 SFER STJO SYOG THTI THU3 TIXI TOW2 TRAB TRO1 UNSA URUM VESL YAKT YSSK ZIMM 4) Sites with different alignment & realization points Six sites used in the reference frame realization had experienced significant discontinuity since the original IGS realization and since ITRF2000 became official. In the IGS cumulative solution (updated weekly), at stations with identified discontinuities, the position/velocity were estimated independently. For the alignment/realization, the independent velocity estimates at a station were combined to provide a unique velocity per site. The sites with estimated discontinuity are: BILI COCO FAIR GUAM HOFN KOKB The cumulative solution for GPS week 1231 (IGS03P33.snx) was used for the proposed IGS2000(v2). 5) Alignment to ITRF2000 After forcing unique velocity estimate at selected sites on the cumulative solution IGS03P33.snx; the 71 common stations between ITRF2000 and the IGS2000(v2) realization (listed below) were used for the alignment: ALGO ASC1 AUCK BAHR BOR1 BRUS CAS1 CHAT CHUR COCO DAV1 DGAR DRAO DUBO EISL FAIR FLIN FORT GLSV GODE GOLD GRAS GRAZ HOB2 HOFN HRAO IISC IRKT KARR KELY KERG KIT3 KOUR KSTU LAMA LHAS LPGS MAC1 MAS1 MATE MAW1 MCM4 MDO1 MKEA NLIB NOUM NRC1 NTUS NYAL ONSA PERT PIE1 POL2 POTS RIOG SANT SCH2 STJO SYOG TIDB TIXI TOW2 TROM TSKB VILL WES2 WSRT WTZR YAR1 YELL ZIMM =20 The other stations were not used in the alignment either because: 1) There was significant difference in position and/or velocity between ITRF and its IGS proposed realization. - or - 2) The station was not available in ITRF2000. Those 28 "orphan" stations are: ALIC ARTU BILI CEDU CRO1 DARW GOUG GUAM JAB1 JOZE KOKB MAG0 MALI MANA NICO NKLG OHI2 PETP RBAY SFER THTI THU3 TRAB TRO1 UNSA URUM VESL YAKT YSSK Note: unit weights were used for the alignment process. 5.1) ITRF2000 - IGS03P33_RS99.snx The residuals (below) between ITRF2000 and the 71 stations used in the alignment. The RMS of the residuals is sub-mm in the horizontal position and velocity, and 2.6mm & 1.5mm/y in vertical position and velocity. Code Pt Soln d. Lat d. Lon d. Hei d.VLat d.VLon d.VHei (mm) (mm) (mm) (mm/y) (mm/y) (mm/y) ALGO A ---- -.1 -.1 2.0 -.3 -.2 -1.9 ASC1 A ---- .1 -.8 2.2 .3 .3 -1.6 AUCK A ---- .8 .3 -.6 -.3 .9 1.7 BAHR A ---- -.5 .7 1.1 -.4 -2.0 -1.0 BOR1 A ---- -.2 -.4 2.2 -.1 -.4 -.2 BRUS A ---- -.1 -.4 .2 .3 .0 -.6 CAS1 A ---- .4 .5 -4.3 .3 .1 .8 CHAT A ---- .9 -.1 -.6 -.2 .3 1.5 CHUR A ---- -.3 -.3 -.6 -.4 -.1 2.1 COCO A 1 -.5 2.3 .0 .4 -2.3 .0 DAV1 A ---- -.7 .2 -1.2 .8 .1 1.7 DGAR A ---- -.4 .0 -.8 .3 -.1 .6 DRAO A ---- -.2 -.7 -.1 -.5 .0 -.4 DUBO A ---- -1.0 -.3 1.7 .1 .3 -2.4 EISL A ---- .0 1.1 -2.5 1.1 -1.4 2.0 FAIR A 1 -.5 -.3 .0 -.8 -.6 3.1 FLIN A ---- -.7 -.1 -2.0 -1.2 .5 1.5 FORT A ---- .3 -.1 4.3 1.3 -.4 1.0 GLSV A ---- -.2 .5 -1.3 -.5 -.5 1.7 GODE A ---- .3 .2 -2.1 -.4 .0 .1 GOLD A ---- .2 -1.2 -.6 .2 2.9 -3.0 GRAS A ---- -.8 -.5 -2.6 -.2 -.1 -.6 GRAZ A ---- -.4 .1 .0 .2 .7 -2.1 HOB2 A ---- .8 .0 -.2 .1 .6 -3.2 HOFN A 1 .6 -.3 -5.5 -.6 .9 .6 HRAO A ---- .6 -1.4 -3.0 .5 .1 .4 IISC A ---- -.5 .5 -1.1 .4 .2 1.8 IRKT A ---- -.5 -.1 .6 .0 .6 -1.2 KARR A ---- -.9 .6 -6.7 .8 -.3 1.6 KELY A ---- -.6 -.4 -1.3 -.5 .1 1.3 KERG A ---- -.5 .6 3.5 .2 .3 .6 KIT3 A ---- -.2 .3 1.1 .4 .3 1.3 KOUR A ---- .0 .0 4.0 1.0 -.1 -1.0 KSTU A ---- -.1 .7 4.3 -1.5 .0 -2.6 LAMA A ---- -.5 .7 -2.3 .9 .6 2.4 LHAS A ---- -1.1 .4 1.5 .2 1.3 1.3 LPGS A ---- .5 1.5 2.3 1.0 -.6 -.8 MAC1 A ---- .3 -.3 .8 -.8 .9 -1.0 MAS1 A ---- -.1 -.7 .3 -.3 .4 .2 MATE A ---- -.1 -.3 1.8 .3 -.8 -1.7 MAW1 A ---- -.4 -.8 -3.8 .6 .5 1.8 MCM4 A ---- .0 .5 3.2 .2 .8 -1.0 MDO1 A ---- .0 -.9 -1.7 .0 .3 -.3 MKEA A ---- .2 -1.6 2.4 -.3 .8 -2.2 NLIB A ---- .0 -.5 .7 .2 .4 -2.3 NOUM A ---- 2.9 1.5 -.9 -.5 -.3 -.6 NRC1 A ---- .0 -.6 -.3 .0 .1 .1 NTUS A ---- -2.1 .2 2.2 3.0 .7 -.1 NYAL A ---- .1 -1.0 2.9 .0 -.3 -.9 ONSA A ---- -.3 -.3 -.1 -.3 .1 2.0 PERT A ---- -.1 .1 3.0 .1 .3 2.4 PIE1 A ---- -.7 -1.2 -4.8 -.5 -.8 -2.0 POL2 A ---- -.8 .5 2.5 -.5 .3 .3 POTS A ---- -.2 -.3 -.9 .1 .1 -.2 RIOG A ---- -1.4 1.0 -4.3 1.2 .0 .7 SANT A ---- .7 .9 2.2 1.4 -1.9 1.9 SCH2 A ---- -.4 -.1 -3.2 -.6 -.3 .5 STJO A ---- .1 -.2 -.4 -.4 -1.0 -.6 SYOG A ---- 1.8 .0 4.0 -.6 -.5 -2.5 TIDB A ---- .6 -.4 -.2 .1 .7 -2.0 TIXI A ---- .5 2.7 2.0 -.6 -1.3 .2 TOW2 A ---- -.1 -.8 -4.4 .5 1.1 2.2 TROM A ---- .0 -2.2 3.3 -.1 -1.3 1.4 TSKB A ---- -.9 -1.2 4.7 -1.6 -.7 -.6 VILL A ---- -.5 -.2 2.1 .2 -.3 -1.1 WES2 A ---- -.9 2.2 .6 .2 .7 -1.8 WSRT A ---- .0 -.1 -.8 -.1 .3 .5 WTZR A ---- -.2 -.4 1.5 -.1 -.2 -1.2 YAR1 A ---- -.3 .1 -1.0 .2 .2 -.1 YELL A ---- -.2 -.4 .5 .0 -.1 -.5 ZIMM A ---- -1.3 .3 -6.5 .5 -.7 2.2 =20 5.2) NNR-NUVEL1A - IGS03P33_RS99.snx Comparison with the plate motion model provides some "quality" control over the estimated velocity field in the cumulative solution. Since the current plate motion model is limited to the horizontal components, the estimated vertical velocity is=20 compared to a null (0.0mm/y) velocity. On most of the Earth surface, vertical velocity is expected to be small, except in active zones. The vertical velocity for the stations CHUR & SCH2 is consistent with expected post-glacial rebound. Stations with large horizontal residuals are generally located close to tectonic plate boundaries (E.g.: GUAM, LHAS, SANT). Excluding stations CHUR, EISL, GUAM, IISC, LHAS, MAC1, NTUS, PETP, SANT, SCH2 and URUM, the RMS between NNR-NUVEL1A and the proposed realization is 3.0mm/y,2.3mm/y and 2.9mm/y in the north, east and vertical velocity components. Code Pt Soln d.VLat d.VLon d.VHei =20 (mm/y) (mm/y) (mm/y) =20 ALGO A ---- 1.5 -.6 -4.3 ALIC A ---- 1.4 .9 -3.7 ARTU A ---- -2.1 -.4 .7 ASC1 A ---- 1.4 -.5 1.0 AUCK A ---- -1.3 1.8 -1.4 BAHR A ---- 6.7 -2.8 -1.5 BILI A ---- .1 2.0 -1.6 BOR1 A ---- -1.0 -.1 1.0 BRUS A ---- .7 .4 -1.1 CAS1 A ---- 1.2 -.6 -2.9 CEDU A ---- .9 -.4 -2.1 CHAT A ---- -.8 1.2 -1.1 CHUR A ---- 1.1 -1.5 -10.0 COCO A 2 4.5 -.1 -1.9 CRO1 A ---- -1.7 -6.2 5.8 DARW A ---- 3.5 1.9 -1.9 DAV1 A ---- 2.8 -.7 -2.6 DGAR A ---- 9.5 -1.8 -2.1 DRAO A ---- -1.6 -1.8 -1.7 DUBO A ---- .3 -.7 2.9 EISL A ---- -.3 11.6 1.8 FAIR A 2 1.6 -2.1 2.7 FLIN A ---- 1.3 -.9 -1.6 FORT A ---- .8 -1.6 .1 GLSV A ---- -1.1 .6 .7 GODE A ---- .4 -.5 2.0 GOLD A ---- -6.3 7.7 -1.7 GOUG A ---- .5 4.3 5.2 GRAS A ---- -.5 -.3 .3 GRAZ A ---- -1.2 -.4 .2 GUAM A 2 -2.5 -29.9 -1.8 HOB2 A ---- -.9 -.4 -4.5 HOFN A 2 1.0 -.9 -6.4 HRAO A ---- 2.7 2.7 .0 IISC A ---- 8.0 -.4 .0 IRKT A ---- -1.1 -1.3 -1.1 JAB1 A ---- 3.1 1.1 -1.5 JOZE A ---- -.8 -.4 1.9 KARR A ---- 3.1 1.3 -4.5 KELY B ---- 2.0 -1.4 .8 KERG A ---- 2.0 .7 -4.3 KIT3 A ---- -3.4 -1.6 2.8 KOKB A 2 -.3 4.5 -2.7 KOUR A ---- .1 -1.4 -3.6 KSTU A ---- -1.5 -.7 .5 LAMA A ---- -.7 1.6 4.3 LHAS A ---- 28.9 -7.1 1.3 LPGS A ---- .3 -.8 -1.9 MAC1 A ---- -5.9 -9.0 -1.1 MAG0 A ---- 4.3 2.2 2.8 MALI A ---- 3.5 -1.2 -1.9 MANA A ---- -5.4 .0 -3.1 MAS1 A ---- .6 .8 -1.2 MATE A ---- -4.9 -2.4 -.7 MAW1 A ---- 3.5 .8 -.9 MCM4 A ---- .2 -1.3 -1.7 MDO1 A ---- .1 .5 .3 MKEA A ---- -.8 5.3 .9 NICO A ---- -4.7 5.3 -1.0 NKLG A ---- 2.4 3.2 1.1 NLIB A ---- .3 -.3 .6 NOUM A ---- -1.9 2.7 -.7 NRC1 A ---- 1.3 -.5 -3.5 NTUS A ---- -2.3 -9.4 -1.5 NYAL A ---- -.4 2.2 -7.3 OHI2 A ---- 3.7 -.6 -8.4 ONSA A ---- -.3 1.4 -.6 PERT A ---- 1.8 -.7 2.4 PETP A ---- -12.0 12.7 .7 PIE1 A ---- .6 .2 -1.6 POL2 A ---- -5.3 -1.6 .3 POTS A ---- -.7 .7 1.1 RBAY A ---- 4.0 2.5 -2.8 RIOG A ---- -.7 -1.6 -4.5 SANT A ---- -5.5 -21.7 -2.8 SCH2 A ---- .2 -.7 -10.8 SFER A ---- 1.4 2.1 -1.4 STJO A ---- 1.0 -.3 -.8 SYOG A ---- 3.1 1.4 -4.6 THTI A ---- -.1 4.0 2.3 THU3 A ---- .0 .0 4.4 TIDB A ---- -1.1 .0 -3.4 TIXI A ---- -.5 .8 .9 TOW2 A ---- .7 1.8 -3.3 TRAB A ---- -4.2 -.9 -.4 TRO1 A ---- -3.1 .1 -2.3 TSKB A ---- 15.0 .4 .0 UNSA A ---- -.4 -8.1 -.1 URUM A ---- -11.5 -3.9 -2.7 VESL A ---- 2.1 3.6 -4.2 VILL A ---- .1 -.8 .4 WES2 A ---- 1.5 .2 -.8 WSRT A ---- -.8 .6 -.2 WTZR A ---- -1.0 -.1 -.3 YAKT A ---- -1.2 -3.7 -7.1 YAR1 A ---- 3.4 .1 -.4 YELL A ---- .7 -1.3 -5.5 YSSK A ---- -1.7 5.0 -2.8 ZIMM A ---- -.3 -1.1 2.7 =20 6) Transformation IGS2000(v2) -> IGS2000(v1) IGS2000(v1) was originally aligned to ITRF2000 using 54 stations. It included data up to fall 2001. IGS2000(v2) was also aligned to ITRF2000 using 70 stations. It includes data until a few weeks ago. A 14 parameter transformation was estimated using the following 44 stations:=20 ALGO ASC1 AUCK BAHR CAS1 CHAT DAV1 DGAR DRAO FAIR FORT GODE GOLD GRAZ HOB2 HRAO IRKT KERG KIT3 KOUR LHAS LPGS MAC1 MALI MAS1 MATE MCM4 MDO1 NLIB NYAL ONSA PERT PIE1 POTS RIOG SANT TIDB TROM TSKB VILL WES2 WTZR YAR1 YELL 6.1) Estimated 14 parameters: R X (mas) : .00069 R Y (mas) : .00380 R Z (mas) : -.00598 T X (m) : -.00011 T Y (m) : .00016 T Z (m) : .00015 SCL (ppb) : .11586 d R X (mas/y) : -.00405 d R Y (mas/y) : -.00506 d R Z (mas/y) : .00008 d T X (m/y) : -.00004 d T Y (m/y) : -.00022 d T Z (m/y) : -.00012 d SCL (ppb/y) : -.05650 At reference epoch 1998.0 In a perfect world, the transformation parameters would be null. However due to data & network selection effects, there are some small transformations. Note: unit weights were used for the alignment process. 6.2) Residuals IGS01P37_RS54.snx - IGS03P33_RS99.snx(transformed): Code Pt Soln d. Lat d. Lon d. Hei d.VLat d.VLon d.VHei (mm) (mm) (mm) (mm/y) (mm/y) (mm/y) ALGO A ---- .1 .1 -.1 .0 .3 .6 ASC1 A ---- -.1 -.1 .9 -.4 .2 -1.6 AUCK A ---- .0 .1 -.5 -.2 .3 .1 BAHR A ---- .0 .7 .1 -.1 -1.0 .4 CAS1 A ---- .1 -.3 -.1 .1 .4 -.2 CHAT A ---- -.1 .0 -.2 -.3 -.3 -.5 DAV1 A ---- .1 -.2 -.9 .0 .3 1.0 DGAR A ---- -.2 .2 -1.0 .4 -.1 .7 DRAO A ---- .2 .1 .1 -.2 -.4 -.4 FAIR A 1 .1 .2 .0 -.4 -.1 -.9 FORT A ---- .1 -.3 .1 -.1 -.8 .3 GODE A ---- .1 .1 -.5 -.1 .9 .6 GOLD A ---- .3 .1 .4 -.2 -.2 -1.5 GRAZ A ---- -.1 .0 .0 .1 .6 -.1 HOB2 A ---- -.1 -.3 .1 .4 .3 -.3 HRAO A ---- -.8 -.4 -1.4 .7 .3 .5 IRKT A ---- .0 .1 .2 .0 .1 .1 KERG A ---- -.1 .2 .0 -.1 .2 1.0 KIT3 A ---- .0 .0 -.2 .3 -.1 .5 KOUR A ---- .1 .0 .1 -.4 -.5 -.3 LHAS A ---- -.1 .3 .4 .3 .3 -1.2 LPGS A ---- .2 .1 .1 -.1 .2 .3 MAC1 A ---- .1 -.3 -.3 -.5 .5 .0 MALI A ---- .0 .3 -.2 1.1 -2.2 -1.2 MAS1 A ---- -.1 -.1 -.8 .0 .3 .9 MATE A ---- -.1 -.1 -.2 .0 .2 .5 MCM4 A ---- -.1 .0 .2 .0 .5 1.7 MDO1 A ---- .3 .0 .4 -.2 -.1 -1.3 NLIB A ---- .2 .0 .2 .0 .1 -.6 NYAL A ---- .3 -.1 .3 1.1 .5 .2 ONSA A ---- .0 -.1 .3 .3 .2 -.6 PERT A ---- -.1 -.5 .6 .3 .4 1.5 PIE1 A ---- .3 .1 .3 -.5 .0 -.6 POTS A ---- .0 -.2 -.1 .1 .2 .2 RIOG A ---- -1.5 .6 1.2 .7 -.4 -.5 SANT A ---- .4 .1 .3 -.1 -.2 .6 TIDB A ---- .0 -.4 -.2 .7 .6 -.2 TROM A ---- .0 -.2 .4 .0 .3 1.0 TSKB A ---- -.2 .3 .2 .1 -.9 .4 VILL A ---- -.1 .0 -.4 .0 .2 .2 WES2 A ---- .3 .2 -.2 .4 .7 .6 WSRT A ---- .0 -.1 -.8 -.1 .3 .5 WTZR A ---- -.1 -.2 -.2 .0 .1 .5 YAR1 A ---- -.2 -.4 .7 .1 .8 -2.4 YELL A ---- .1 .2 -.1 -.1 -.3 .1 =20 R.M.S. .3 .3 .5 .4 .5 .8 =20 These residuals show the effect of adding about two years of weekly solutions to the cumulative solution IGS01P37.snx.=20 7) ERP's The effect of the new IGS realization of ITRF2000 on the ERP's can be estimated with the above estimate of the transformation parameters using formula: (R X) =3D (R X)o + (d R X)*dt (R Y) =3D (R Y)o + (d R Y)*dt With the proposed alignment/realization procedure, there are some small approximations because the realization includes a somewhat different stations set than the transformation parameters estimation uses. As suggested above, these effects are expected to be small. To verify the magnitude of the approximation, eleven weeks (1220-1230) were used to compare the effect of the actual realization changes and the estimated changes (with the 14 parameters transformation) on the pole position. The GPS weeks were reprocessed using the proposed IGS2000(v2) realization. The estimated daily ERP's were compared with the ERP's aligned using the current realization. The difference of the two realizations (IGS00(v1) - IGS00(v2)) on the ERP's are: dXp =3D -0.033 +- 0.005 mas dYp =3D -0.017 +- 0.007 mas Using the above formula, the estimated rotations at GPS week 1225.5 is: (R X) =3D -0.024 mas (R Y) =3D -0.023 mas The two estimates agree at the 0.01mas: (R X) - dYp =3D -0.007 mas (R Y) - dXp =3D 0.010 mas This validates that the estimated transformation parameters are valid, and precise to about 0.01mas. This also indicates that network effects, other than those predicted by the usual 14 transformation parameters are very small on the ERP's. The small rotational differences (-0.007, 0.010mas) can probably be attributed to the additional 52 stations. This is an indication that the station coordinates are highly consistent. The additional stations in the proposed realization probably contribute to the noise reduction in the ERP's. The sigmas on the differences (0.005, 0.007 mas) are probably an indication of the maximum level of that reduction. 8) Apparent Geocenter Similarly, the effect of the proposed IGS realization of ITRF2000 on the apparent geocenter can be estimated with the above transformation parameters using formula: (Xgc) =3D (T X)o + (d T X)*dt (Ygc) =3D (T Y)o + (d T Y)*dt (Zgc) =3D (T Z)o + (d T Z)*dt The approximations discussed above also apply here. The reprocessed weeks can also be used here to verify the effect of the proposed realization on the apparent geocenter. The difference of the two realizations (igs00(v1)-igs00(v2)) on the apparent geocenter are: dXGC =3D -0.4 +- 0.5 mm dYGC =3D -1.2 +- 0.5 mm dZGC =3D 0.0 +- 0.6 mm Using the above formula, the estimated effect on the apparent geocenter for GPS week 1225.5 is: (T X) =3D -0.3 mm (T Y) =3D -1.1 mm (T Z) =3D -0.5 mm Their differences are: (T X) - dXGC =3D 0.1 mm (T Y) - dYGC =3D -0.1 mm (T Z) - dZGC =3D 0.5 mm The two estimates are almost identical (at 0.1mm) in the X&Y components. Although, the level of agreement is slightly less in the Z component, it is still within the noise level. This is a check of the estimated transformation parameters. The discussion above on the ERP's comparison, can certainly be extended to the translation/geocenter test. 9) Misc. The residuals between the proposed realization and the weekly (1220-1230) solutions were also checked. Except for one isolated case, the residuals were all within 3 sigmas. Adding/removing a few stations would unlikely have a=20 significant impact on the above results. Once the final set is agreed, the latest cumulative solution will be used to generate the final set.