This is an update of the original analysis that was done in May 2001 when the first "Proposed realization of ITRF2000" was made available within the Reference Frame Working Group. 0) Introduction ITRF2000 has recently been made available. A realization of ITRF is proposed following the "IGS Terms of Reference", specifically regarding the accuracy of the products: "Realization of global accessibility to and the improvement of the International Terrestrial Reference Frame(ITRF)" The proposed new realization of the reference frame stations coordinates and velocity, will contribute, when implemented to improve the global accessibility of the ITRF2000. "IGS2000" is suggested as the name for the "proposed" IGS realization of ITRF2000. It is derived from the accumulation of the AC solutions between GPS weeks 0837 and 1110 inclusively. It is formed in a manner very similar to the current IGS97 and with the same accuracy, consistency and coverage objectives. The rationale has been described 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. With the procedures currently in place, the consistency with the other IGS products should be maintained. The "IGS2000" realization is extracted from the cumulative solution "IGS01P37.snx" which currently contains 216 stations. That solution is itself a subset of a more complete solution including all the stations ever contained in the AC weekly solutions since GPS week 0837. The complete solution currently contains 277 stations. 61 stations are currently not released because either: missing essential info such as dome #, missing site logs, short time span (e.g. < 1 year) which prevent reliable velocity estimation, or stations located in geographical areas already well covered (e.g. North America and Europe). ITRF2000 already includes an IGS cumulative solution which was provided last fall. That cumulative solution was an edited solution derived from IGS00P46.snx (GPS weeks 0837 to 1088). The AC/GNAAC (cod,gfz,jpl, ngs,ncl) also provided their own global cumulative solution which are included in ITRF2000. The sections below present the analysis between ITRF97/ITRF2000 and IGS97/IGS2000 using the current Reference Frame (RF) stations. Section 1 gives a short review of some RF stations performance as well as a few strategically located stations considered for the expansion of the RF list. Using the RF stations in ITRF97 and ITRF2000, Section 2 shows the estimated transformation parameters and the residuals between the two ITRF subsets. The same procedure is repeated between the current IGS realization of ITRF97 and the proposed IGS realization of ITRF2000 (IGS2000). Also included in section 3 are comparisons between ITRF97 and IGS 97, as well as between ITRF2000 and IGS2000. In section 4, the ITRF/IGS solutions are propagated from their respective reference epoch to epoch 2001.5 (GPS Week 1121). Since the rate of changes are small, it should closely approximate expected discontinuity at the time of IGS2000 implementation. Section 5 shows some comparisons ot the ITRF/IGS estimated RF stations w.r.t. to NNR-NUVEL1A plate motion model. Some comparisons involving ITRF97/IGS97 have been included to show the level of change since last year implementation of IGS97. The proposed realization of ITRF will cause a small discontinuity on the ERPs. Section 6 summarize the expected effect on the pole position. 1) Review of some stations Most RF stations are providing consistent quality data. The RF stations in the northern hemisphere have generally excellent performance. There is however some sites that are of concern in the southern hemisphere. This is also where alternate quality sites are difficult to find. To include alternate sites in some areas may require to accept some shortcomings. BRAZ is of concern. It was only present in the weekly combination for only one week during the last year. There is unfortunately no alternate sites in the area. The two closest sites are AREQ and FORT. They are already used as RF stations. It is proposed not to include it in IGS2000. One possibility further south at the southern tip of South America is RIOG. It has a stable time series residuals (over 3 years) in the IGS combination. The vertical velocity large at 8mm/y. It is already used by most AC most of the time. The performance is also excellent most of the time. The antenna is on a concrete pillar. It is also collocated with DORIS. It is proposed to add it in IGS2000. Folloing J. Ray suggestion, the station LPGS (La Plata, Argentina) was added in south America. KIT3 contribution has been irregular lately due to communication problems. Measures are being taken to resolve the problem by the responsible on-site agency. Once the internet connection is available at the site(May 2001?), the situation is expected to get back to normal. It is proposed to keep it. (As of October, the situation is still not resolved????). POL2 is being considered as a possible alternative. Some weekly solutions for stations MALI were missing lately, but with the recent improvements in the communication, the station is expected to resume normal operations. It is proposed to keep it. (As of October, the station is performing well). Weekly solutions for PERT have not been available for the last 3 months. A potential alternative may be CEDU. It is located half way between YAR1 and TID2. Time series has been available for about 2.5 years. Its horizontal (N,E) velocity agree well (-1.8 mm/y, 2.0mm/y) with the plate motion model. However, its vertical velocity is at the moment somewhat of a concern (9mm/y). TID2 and YAR1 have respectively 3.4mm/y and -2.0mm/y. The antenna is mounted on a concrete pillar. PERT was used by most AC while CEDU is used regularly by only 2 AC. Following J. Ray suggestion, PERT is kept and CEDU is added. As of October, PERT has resumed normal operation. NKLG (Gabon) and YKRO (Cote d'Ivoire) are strategically located in Africa. They were considered for addition to the RF list; but their time series are still too short (less than one year) to have reliable velocity. Monumentation stability is unknown. It is proposed not to include them at this time. As of October, NKLG is continues normal operations, while no data is currently available from YKRO. Two other potential additions considered are ASC1 and DGAR. They both have stable time series residuals (5 years) with small vertical velocity (ASC1 -2.7mm/y, DGAR 1.7mm/y). ASC1 (Ascension Island) is located halfway between South America and Africa. DGAR is located halfway between Africa and Australia; ASC1 time series was interrupted recently (GPS weeks 1092-1101). Both ASC1 and DGAR would fill a void on either side of Africa. Quality indicators available for those stations show that they generally provide quality and timely data. All the AC includes those two stations most of the time. However, both sites have roof top monumentation, which may cause some stability concerns, and neither site is collocated. The two stations have been added. The station AREQ was removed due to an earthquake that did occur on June 23. A new solution was started after the earthquake. The estimated mouvement, based on the cumulative solution "IGS01P38.snx" using the "before" and "after" estimates for the station propagated at the epoch of the earthquake is: Station dx dy dz Distance from dp dl dh to (m.) (m.) (m.) (m.) AREQ A 1 -.466 -.026 -.294 AREQ A 2 -.317 -.450 -.035 .551 The latest list of proposed RF stations includes 54 stations. The station changes, in summary: - Removed: BRAZ, AREQ - Added: ASC1, CEDU, DGAR, LPGS, RIOG. 2) ITRF2000 -> ITRF97 (1997.0) ITRF97 and ITRF2000 RF stations are compared at their reference epoch (1997.0). A 14-parameters transformation is estimated (Table 2.1). In the table, the estimated parameters are derived from an unweighted least-squares adjustment. This ensures consistency with previously estimated transformations and weekly combinations. Transformation parameters estimates with the covariance information are almost identical to those provided below. The "Formal Sigmas" in the table are derived from the propagation of the covariance information of the RF stations contained in the two ITRF solutions without rescaling. The [XYZ] translations, the scale, the Z rotation Rate and the YZ translation rate are the more significant parameters (at >3sigmas, see * below). The residuals are shown in Table 2.2. The RMS of the residuals are at the mm and mm/y for the horizontal components, while they are at the 3mm and 3mm/y for the vertical position and velocity respectively. Table 2.1 Transformation (from ITRF2000 to ITRF97) (1997.0) --------- Parameter Estimate Formal Sigma Normalized R X (mas) : .03924 .01697 2.3 R Y (mas) : .00293 .01776 0.2 R Z (mas) : .01035 .01674 0.6 T X (m) : .00620 .00072 8.6 * T Y (m) : .00634 .00076 8.3 * T Z (m) : -.01832 .00122 -15.0 * SCL (ppb) : 1.32540 .32246 4.1 * d R X (mas/y) : -.00418 .00250 -1.7 d R Y (mas/y) : -.00888 .00324 -2.7 d R Z (mas/y) : .03543 .00274 12.9 * d T X (m/y) : -.00003 .00010 -0.3 d T Y (m/y) : -.00089 .00012 -7.4 * d T Z (m/y) : -.00157 .00030 -5.2 * d SCL (ppb/y) : .06735 .04286 1.6 Table 2.2 Residuals (ITRF2000(transformed) minus ITRF97. --------- Code Pt Soln d d. Lat d. Lon d. Hei d.VLat d.VLon d.VHei (mm) (mm) (mm) (mm/y) (mm/y) (mm/y) ALGO A ---- d -.4 .1 -.1 .0 .3 1.4 AUCK A ---- d .4 -.1 -1.1 .7 -.1 1.3 BAHR A ---- d 1.0 -.1 5.0 -1.9 -1.1 -2.7 BRMU A ---- d -.4 -.3 -.4 .3 -.2 -.7 CAS1 A ---- d -.3 2.9 -4.9 1.0 .1 -5.3 CHAT A ---- d .4 -.6 -3.0 -.3 -.1 3.0 DAV1 A ---- d -1.7 1.3 -4.0 .7 .3 .1 DRAO A ---- d -.8 -.2 -1.9 -.1 .2 -.6 FAIR A ---- d -.5 .2 -13.0 -.1 .4 -.3 FORT A ---- d .5 -1.3 .4 1.1 .1 .2 GODE A ---- d .0 .2 3.5 -.1 .6 -1.5 GOL2 A ---- d -1.6 -1.6 -1.4 -.3 .0 -.3 GRAZ A ---- d -.3 .2 -1.5 .4 .3 -1.7 GUAM A ---- d -.7 -1.5 -.9 .1 -1.6 1.9 HOB2 A ---- d .5 .1 -.6 .6 .0 .7 IRKT A ---- d -.6 -.2 2.6 -.1 -.5 -2.0 KERG A ---- d -.8 1.7 3.1 1.1 -.1 -2.5 KIT3 A ---- d -.4 .2 .7 -.2 -.9 -3.9 KOKB A ---- d -1.7 .9 3.3 -.4 .4 -1.5 KOUR A ---- d .0 -1.2 1.3 .5 -.7 2.1 KWJ1 A ---- d -.7 -.3 1.4 .9 -.9 2.3 LHAS A ---- d -.4 -.9 .2 -1.2 1.0 -3.5 MAC1 A ---- d .2 .9 .5 -.4 -2.4 -1.8 MALI A ---- d .4 .3 -1.0 .8 .0 7.6 MAS1 A ---- d .8 -.2 .4 1.1 .9 1.2 MATE A ---- d -.1 .4 -.4 .0 .3 -1.3 MCM4 A ---- d -.6 1.3 -4.3 -.8 -1.7 9.6 MDO1 A ---- d -1.3 -.2 .5 -.1 .6 -1.4 NLIB A ---- d -1.0 -.4 1.5 -.1 .4 .9 NYAL A ---- d .8 -.2 10.5 .1 -.1 4.8 OHIG A ---- d .8 1.1 .5 1.3 -.7 -1.7 ONSA A ---- d .3 .1 -3.7 .0 .0 .0 PERT A ---- d .3 .7 3.4 .0 .3 -2.3 PIE1 A ---- d -1.4 .6 -.3 -.6 .1 -1.0 POTS A ---- d .2 .2 -2.0 .0 -.4 -1.5 SANT A ---- d .7 -.1 1.7 2.3 1.6 -1.2 SHAO A ---- d -.9 -1.1 .6 -.2 -.1 -1.0 THU1 A ---- d -.4 -.6 -6.8 -.9 .4 4.8 TIDB A ---- d 1.4 .8 -.7 .5 .3 2.0 TROM A ---- d -.2 1.1 1.1 -.5 .7 1.7 TSKB A ---- d -.8 -1.6 .6 1.3 -1.0 2.8 VILL A ---- d .0 -.2 3.6 1.0 1.0 -2.7 WES2 A ---- d -2.0 2.3 1.7 -.2 .5 .3 WSRT A ---- d .1 .3 .5 .0 .4 -1.2 WTZR A ---- d .0 .1 .1 .3 .0 .5 YAR1 A ---- d .1 .8 2.0 .1 .9 -1.8 YELL A ---- d -1.1 -.7 -1.2 -.2 -.2 .2 ZWEN A ---- d -.2 .1 2.1 -.4 .1 -3.6 Obs. Mean -.3 .1 .0 .1 .0 .0 Mean Std. .8 .9 3.4 .7 .7 2.8 R.M.S. .8 .9 3.4 .7 .7 2.8 3) IGS2000 -> IGS97 (1998.0) The IGS2000 solution was aligned to ITRF2000 with an unweighted 14-parameters similarity transformation using the RF stations at the reference epoch (1998.0) . The IGS97 was already aligned in a very similar way to ITRF97. Since the IGS97 was generated from solution IGS00P04.snx, an extra 83 weeks have been added to the cumulative solution. IGS97 and IGS2000 stations are compared at their reference epoch (1998.0). The 14-parameters transformation and the formal sigmas are estimated as described in section 2. The residuals are shown in Table 3.2. The residuals show the effect of the additionnal 83 weeks in the more recent cumulative solution. Note that when brought back to the same epoch, the estimated transformation parameters in Tables 2.1 and 3.1 are identical (within 1 sigma). Table 3.3 and 3.4 show respectively the level of agreement between ITRF97/ITRF2000 and their IGS realizations IGS97/IGS2000. The Z translation and scale parameters in Table 3.1 are also here the more significant parameters (at 3 sigmas). Table 3.1 Transformation (from IGS2000 to IGS97) (1998.0) --------- Parameter Estimate Formal Sigma Normalized R X (mas) : .04039 .05332 0.8 R Y (mas) : -.00144 .05957 0.0 R Z (mas) : .04268 .03586 1.2 T X (m) : .00600 .00253 2.4 T Y (m) : .00561 .00327 1.7 T Z (m) : -.02007 .00508 -4.0 * SCL (ppb) : 1.40332 .12066 11.6 * d R X (mas/y) : -.00422 .03800 -0.1 d R Y (mas/y) : .00133 .03998 0.0 d R Z (mas/y) : .02960 .03366 0.9 d T X (m/y) : -.00038 .00165 -0.2 d T Y (m/y) : -.00083 .00193 -0.4 d T Z (m/y) : -.00152 .00277 -0.5 d SCL (ppb/y) : .01215 .12191 0.1 Table 3.2 Residuals (IGS2000(transformed) minus IGS97). --------- Code Pt Soln d d. Lat d. Lon d. Hei d.VLat d.VLon d.VHei (mm) (mm) (mm) (mm/y) (mm/y) (mm/y) ALGO A ---- d -.2 .1 .2 -.2 -.1 .1 AUCK A ---- d .1 -.1 -.5 .1 .2 -1.4 BAHR A ---- d .2 -.3 -.1 .4 1.2 1.6 BRMU A ---- d -.1 .0 .0 -.1 -.4 -.6 CAS1 A ---- d -.3 .0 1.4 -.6 .0 3.4 CHAT A ---- d .0 -.1 -.6 .1 .2 -1.4 DAV1 A ---- d -.2 .0 .9 -.7 -.2 1.6 DRAO A ---- d .2 .3 .1 .5 .3 .1 FAIR A ---- d .0 .1 .8 .0 .3 1.4 FORT A ---- d -.4 .5 -1.1 -.9 .4 -2.5 GODE A ---- d -.1 -.1 .6 .1 -.5 .9 GOL2 A ---- d .1 -.6 .3 .3 -1.3 1.1 GRAZ A ---- d .3 .0 .4 .4 -.1 2.2 GUAM A ---- d -.1 -.3 -.6 .0 -.1 -1.6 HOB2 A ---- d -.1 -.2 -.3 -.4 -.1 2.8 IRKT A ---- d .1 .2 .8 .4 -.1 2.5 KERG A ---- d .1 -.5 -.6 -.3 -.8 -1.8 KIT3 A ---- d -.2 -.2 .6 -.2 -.7 .2 KOKB A ---- d .1 -.1 -.3 .5 -.4 -.9 KOUR A ---- d -.5 -.6 -1.0 -.8 -1.0 -3.0 KWJ1 A ---- d .0 .1 -.5 .1 .4 -1.9 LHAS A ---- d .1 -.2 -.6 .1 -1.3 -4.6 MAC1 A ---- d .2 .0 -.1 .7 .2 -.8 MALI A ---- d -.3 .2 -.4 -1.0 2.1 1.7 MAS1 A ---- d .2 -.1 .7 .3 -.5 1.4 MATE A ---- d .0 .3 .3 -.1 .5 .0 MCM4 A ---- d -.1 .0 1.1 -.2 .1 2.2 MDO1 A ---- d .2 .3 .7 .5 .1 1.8 NLIB A ---- d .1 .3 .0 .3 .2 -1.1 NYAL A ---- d .0 .3 -.8 .2 .1 -2.5 OHIG A ---- d .0 -.6 .3 -.4 -1.0 -1.0 ONSA A ---- d .2 .1 .5 .3 .1 1.6 PERT A ---- d .2 -.1 -1.1 .1 -.5 -2.6 PIE1 A ---- d .3 .2 .5 .6 .1 1.6 POTS A ---- d .1 .1 .3 .1 .0 .7 SANT A ---- d .1 .5 -.3 -.1 1.1 -1.3 SHAO A ---- d -.3 .0 .8 -.1 .3 .3 THU1 A ---- d -.2 -.1 .5 -.4 -.4 1.0 TIDB A ---- d -.1 -.3 .2 -.3 -.5 2.0 TROM A ---- d .0 1.0 -3.0 .2 .5 -3.2 TSKB A ---- d .4 .5 -.2 1.0 1.7 -1.8 VILL A ---- d .3 .1 -.4 .4 .2 -.8 WES2 A ---- d -.3 .1 .0 -.4 -.5 -.8 WSRT A ---- d .0 -.1 -.9 .4 .0 1.9 WTZR A ---- d .1 .1 .5 .2 .0 .6 YAR1 A ---- d .3 -.1 .2 .2 -.5 .4 YELL A ---- d -.3 .3 .1 -.5 .4 .3 ZWEN A ---- d .1 .0 .5 -.4 -.2 .2 Obs. Mean .0 .0 .0 .0 .0 .0 Mean Std. .2 .3 .7 .4 .7 1.8 R.M.S. .2 .3 .7 .4 .6 1.8 Table 3.3 Residuals (ITRF97 minus IGS97). --------- Code Pt Soln d d. Lat d. Lon d. Hei d.VLat d.VLon d.VHei (mm) (mm) (mm) (mm/y) (mm/y) (mm/y) ALGO A ---- d .0 -.2 .4 -.4 -.5 -3.1 AREQ A ---- d -2.2 .6 -.4 -.9 -.4 .4 AUCK A ---- d -.6 1.0 -1.9 -1.0 .8 -.8 BAHR A ---- d .8 .9 -2.3 2.1 1.4 3.9 BRAZ A ---- d -2.8 -.5 -5.5 -2.6 -1.8 -11.5 BRMU A ---- d -.1 .8 .8 -.1 -.1 .5 CAS1 A ---- d -1.3 -2.4 6.4 -1.3 -1.0 10.4 CHAT A ---- d .4 1.1 -1.9 .0 .8 -2.0 DAV1 A ---- d -.4 -1.8 3.5 -.2 -1.1 2.9 DRAO A ---- d .7 -.2 1.7 .4 .9 1.2 FAIR A ---- d -.1 -.7 13.3 -.2 -.5 6.4 FORT A ---- d -1.4 2.1 2.2 -.4 1.2 -1.1 GODE A ---- d .3 -.5 -3.5 -.1 -1.5 2.5 GOL2 A ---- d 1.7 1.3 .3 1.2 2.1 .4 GRAZ A ---- d .0 -.4 2.9 .1 -.2 2.9 GUAM A ---- d .4 2.4 2.2 -.6 2.6 -2.3 HARK A ---- d 2.0 -2.2 -2.2 -3.2 -1.8 -3.3 HOB2 A ---- d -.9 .5 -1.7 -1.5 -.2 -.3 IRKT A ---- d .4 .9 -.3 .5 .8 4.1 KERG A ---- d -.9 -2.2 1.4 -.6 -.8 1.2 KIT3 A ---- d .2 .9 4.2 .0 .5 5.9 KOKB A ---- d 2.2 -2.0 5.1 1.2 -.4 -3.3 KOUR A ---- d -.6 1.7 -.8 .2 .7 -4.9 KWJ1 A ---- d -.2 .8 -1.6 -1.2 1.5 -3.4 LHAS A ---- d .6 .0 2.8 1.4 -1.4 2.4 MAC1 A ---- d .0 1.9 1.2 .4 2.7 .5 MALI A ---- d -1.1 -1.0 -5.3 -.8 -.2 -10.9 MAS1 A ---- d -1.4 -1.4 -.2 -1.0 -.9 .6 MATE A ---- d .2 -.5 3.4 .2 -.6 .2 MCM4 A ---- d .6 1.3 -2.1 .3 1.8 -9.5 MDO1 A ---- d 1.3 -.6 -1.0 .9 .4 4.6 NLIB A ---- d 1.1 .1 -2.5 .7 .5 -3.0 NYAL A ---- d -1.1 -.4 -14.1 -1.2 -.6 -7.5 OHIG A ---- d -1.5 -.6 .0 -1.3 -.3 3.4 ONSA A ---- d -.4 -.2 3.1 -.4 .1 5.2 PERT A ---- d -.6 -.5 -1.1 -.1 -1.3 1.2 PIE1 A ---- d 1.4 -1.3 -3.9 1.3 -.5 1.6 POTS A ---- d -.2 .2 2.4 -.1 .6 2.9 SANT A ---- d -2.1 .3 .6 -1.0 -1.5 1.9 SHAO A ---- d .2 1.5 2.8 -.3 1.6 .6 THU1 A ---- d .4 .1 -1.4 .4 -.1 -3.5 TIDB A ---- d -2.0 -1.0 -2.2 -1.7 -1.1 -1.3 TROM A ---- d .8 -2.8 -3.5 .5 -1.7 -3.5 TSKB A ---- d -.8 2.0 -.3 -1.8 2.7 -5.0 VILL A ---- d -1.1 -1.0 .7 -.5 -1.0 1.7 WES2 A ---- d .7 -.4 -1.6 -.4 -.5 -2.7 WSRT A ---- d -.4 -.8 -2.7 .1 -.5 3.9 WTZR A ---- d -.3 -.3 .9 -.3 -.1 -.4 YAR1 A ---- d -.4 -1.2 -2.9 .3 -2.3 5.1 YELL A ---- d .6 .7 1.1 -.1 1.0 .2 ZWEN A ---- d .7 -.3 3.5 .6 -.5 4.7 Obs. Mean -.1 -.1 .0 -.2 .0 .0 Mean Std. 1.1 1.2 3.8 1.0 1.2 4.3 R.M.S. 1.1 1.2 3.7 1.0 1.2 4.3 Table 3.4 Residuals (ITRF2000 minus IGS2000). --------- Code Pt Soln d d. Lat d. Lon d. Hei d.VLat d.VLon d.VHei (mm) (mm) (mm) (mm/y) (mm/y) (mm/y) ALGO A ---- d -.4 -.1 1.3 -.2 -.3 -2.2 ASC1 A ---- d .2 -.7 .8 .6 .4 .3 AUCK A ---- d .5 .5 -.8 .1 .3 1.8 BAHR A ---- d -.5 .1 .2 -.3 -1.0 -.8 BRMU A ---- d -.4 .2 -.6 .4 -.2 -.1 CAS1 A ---- d .1 .7 -4.9 .5 -.4 1.3 CEDU A ---- d -.1 1.1 -2.7 .3 -.7 .8 CHAT A ---- d .6 .2 -1.1 .2 .2 2.2 DAV1 A ---- d -1.0 .1 -1.0 1.1 -.1 1.0 DGAR A ---- d -.4 -.2 -.6 .2 .1 .4 DRAO A ---- d -.6 -.6 -1.0 -.1 .5 .2 FAIR A ---- d -.8 -.3 -.9 -.2 -.6 4.4 FORT A ---- d .2 .4 3.7 1.3 .6 1.0 GODE A ---- d .0 .2 -2.3 -.3 -.7 -.3 GOL2 A ---- d -.5 .2 -1.7 .7 3.1 -1.3 GRAZ A ---- d -.3 .1 -.7 .1 .2 -1.4 GUAM A ---- d -.2 -.4 4.1 -.3 1.1 1.2 HOB2 A ---- d .6 .5 -1.0 .0 .1 -2.5 HRAO A ---- d 1.4 -1.1 -2.2 -.1 .0 .4 IRKT A ---- d -.5 .0 -.6 .0 .4 -.7 KERG A ---- d -.6 .2 2.8 .6 .3 .1 KIT3 A ---- d -.2 .4 .4 .1 .4 1.4 KOKB A ---- d -.3 -.8 7.4 .5 .1 -4.0 KOUR A ---- d -.1 .2 3.4 1.4 .6 -.4 KWJ1 A ---- d .1 -.7 2.8 -.1 .1 .8 LHAS A ---- d -1.0 .3 .2 .1 .9 3.2 LPGS A ---- d .4 1.7 1.7 1.0 -.7 -1.0 MAC1 A ---- d -.2 .2 .3 -.1 .1 -.7 MALI A ---- d .3 -.7 1.8 .9 -2.2 -5.6 MAS1 A ---- d .0 -.5 .5 -.3 .3 -.3 MATE A ---- d -.1 -.1 1.2 .2 -.8 -1.7 MCM4 A ---- d -.2 .7 2.4 .4 .1 -2.4 MDO1 A ---- d -.5 -.6 -2.7 .4 .5 1.2 NLIB A ---- d -.4 -.3 -.2 .3 .4 -1.4 NYAL A ---- d -.2 -1.0 1.8 -1.3 -.8 -.6 OHIG A ---- d .1 .3 -1.4 .0 -.5 2.2 ONSA A ---- d -.3 -.2 -1.2 -.7 .0 3.2 PERT A ---- d -.3 .6 1.6 .1 -.2 1.3 PIE1 A ---- d -1.2 -1.0 -5.8 .2 -.8 -1.2 POTS A ---- d -.2 -.2 -1.5 -.2 .1 .2 RIOG A ---- d .2 .6 -6.0 .2 .4 1.4 SANT A ---- d .4 1.1 1.4 1.3 -1.6 1.4 SHAO A ---- d -.7 .3 1.7 -.3 1.2 -.9 THU1 A ---- d -.7 .0 -4.2 -.1 .5 -.1 TIDB A ---- d .3 .3 -.7 -.3 -.1 -1.4 TROM A ---- d .1 -2.1 2.1 -.2 -1.6 .9 TSKB A ---- d -.8 -1.2 3.5 -1.5 -.1 -.5 VILL A ---- d -.5 -.3 1.7 .0 -.3 -.9 WES2 A ---- d -1.3 2.1 .1 -.1 .2 -2.1 WSRT A ---- d -.4 -.1 -2.7 -.4 -.2 .2 WTZR A ---- d -.2 -.2 .9 -.2 -.2 -1.1 YAR1 A ---- d -.4 .6 -2.5 .4 -.6 2.7 YELL A ---- d -.5 -.5 -.2 .3 .3 -.2 ZWEN A ---- d -.1 -.1 1.3 .6 -.3 .3 Obs. Mean -.2 .0 .0 .1 .0 .0 Mean Std. .5 .7 2.5 .5 .8 1.8 R.M.S. .5 .7 2.5 .6 .8 1.7 4) ITRF2000/IGS2000 -> ITRF97/IGS97 (2001.5) All the solutions of interest here, have been propagated from their respective reference epoch to a more current epoch (2001.5). Table 4.1.1 shows the transformation between the two IGS realizations of the two ITRF. Table 4.1.2 shows the transformation ITRF2000 to ITRF97 when using only the RF stations. The two sets of transformations are identical within 1 sigma. CAS1 and MCM4 show the larger variations between the two successive ITRF. The changes are much smaller between the two successive IGS realizations of ITRF. This indicates that the two successive IGI realizations of ITRF are about a factor 2 more consistent than the ITRF. Table 4.1.1 Transformation (from IGS2000 to IGS97) (2001.5) --------- Parameter Estimate Formal Sigma Normalized R X (mas) : .02561 .04524 0.6 R Y (mas) : .00323 .05049 0.1 R Z (mas) : .14625 .04382 3.3 * T X (m) : .00469 .00256 1.8 T Y (m) : .00269 .00288 0.9 T Z (m) : -.02541 .00416 -6.1 * SCL (ppb) : 1.44585 .15820 9.1 * d R X (mas/y) : -.00422 .02371 -0.2 d R Y (mas/y) : .00133 .02675 0.0 d R Z (mas/y) : .02960 .01705 1.7 d T X (m/y) : -.00038 .00131 -0.3 d T Y (m/y) : -.00083 .00165 -0.5 d T Z (m/y) : -.00152 .00258 -0.6 d SCL (ppb/y) : .01215 .04891 0.2 Table 4.1.2 Transformation (from ITRF2000 to ITRF97) (2001.5) --------- Parameter Estimate Formal Sigma Normalized R X (mas) : .02043 .02138 1.0 R Y (mas) : -.03701 .02517 -1.5 R Z (mas) : .16973 .02005 8.5 * T X (m) : .00608 .00097 6.3 * T Y (m) : .00234 .00103 2.3 T Z (m) : -.02537 .00209 -12.1 * SCL (ppb) : 1.62839 .41929 3.9 * d R X (mas/y) : -.00418 .00250 -1.7 d R Y (mas/y) : -.00888 .00324 -2.7 d R Z (mas/y) : .03543 .00274 12.9 * d T X (m/y) : -.00003 .00010 -0.3 d T Y (m/y) : -.00089 .00012 -7.4 * d T Z (m/y) : -.00157 .00030 -5.2 * d SCL (ppb/y) : .06735 .04286 1.6 Table 4.2 Residuals (ITRF2000 minus ITRF97). --------- Code Pt Soln d d. Lat d. Lon d. Hei d.VLat d.VLon d.VHei (mm) (mm) (mm) (mm/y) (mm/y) (mm/y) ALGO A ---- d -.5 1.4 6.2 .0 .3 1.4 AUCK A ---- d 3.4 -.8 4.7 .7 -.1 1.3 BAHR A ---- d -7.7 -5.2 -7.0 -1.9 -1.1 -2.7 BRMU A ---- d 1.1 -1.2 -3.5 .3 -.2 -.7 CAS1 A ---- d 4.1 3.5 -28.8 1.0 .1 -5.3 CHAT A ---- d -.9 -1.0 10.4 -.3 -.1 3.0 DAV1 A ---- d 1.5 2.5 -3.4 .7 .3 .1 DRAO A ---- d -1.4 .6 -4.6 -.1 .2 -.6 FAIR A ---- d -1.0 1.9 -14.5 -.1 .4 -.3 FORT A ---- d 5.3 -.6 1.3 1.1 .1 .2 GODE A ---- d -.6 2.8 -3.3 -.1 .6 -1.5 GOL2 A ---- d -2.8 -1.5 -2.7 -.3 .0 -.3 GRAZ A ---- d 1.4 1.5 -9.0 .4 .3 -1.7 GUAM A ---- d -.4 -8.6 7.8 .1 -1.6 1.9 HOB2 A ---- d 3.4 .1 2.7 .6 .0 .7 IRKT A ---- d -.9 -2.5 -6.6 -.1 -.5 -2.0 KERG A ---- d 4.1 1.1 -8.2 1.1 -.1 -2.5 KIT3 A ---- d -1.1 -3.8 -16.8 -.2 -.9 -3.9 KOKB A ---- d -3.7 2.6 -3.4 -.4 .4 -1.5 KOUR A ---- d 2.1 -4.5 10.6 .5 -.7 2.1 KWJ1 A ---- d 3.5 -4.2 11.7 .9 -.9 2.3 LHAS A ---- d -5.6 3.4 -15.6 -1.2 1.0 -3.5 MAC1 A ---- d -1.6 -9.9 -7.5 -.4 -2.4 -1.8 MALI A ---- d 4.2 .2 33.2 .8 .0 7.6 MAS1 A ---- d 5.6 3.8 5.6 1.1 .9 1.2 MATE A ---- d -.3 1.6 -6.4 .0 .3 -1.3 MCM4 A ---- d -4.0 -6.3 38.9 -.8 -1.7 9.6 MDO1 A ---- d -1.7 2.5 -5.7 -.1 .6 -1.4 NLIB A ---- d -1.5 1.4 5.5 -.1 .4 .9 NYAL A ---- d 1.2 -.8 32.0 .1 -.1 4.8 OHIG A ---- d 6.7 -2.0 -7.3 1.3 -.7 -1.7 ONSA A ---- d .5 -.1 -3.6 .0 .0 .0 PERT A ---- d .5 2.0 -6.9 .0 .3 -2.3 PIE1 A ---- d -4.2 1.1 -4.7 -.6 .1 -1.0 POTS A ---- d .2 -1.7 -8.7 .0 -.4 -1.5 SANT A ---- d 11.1 7.2 -3.6 2.3 1.6 -1.2 SHAO A ---- d -1.9 -1.5 -4.2 -.2 -.1 -1.0 THU1 A ---- d -4.4 1.1 14.7 -.9 .4 4.8 TIDB A ---- d 3.8 2.4 8.3 .5 .3 2.0 TROM A ---- d -2.6 4.2 8.6 -.5 .7 1.7 TSKB A ---- d 4.9 -6.2 13.2 1.3 -1.0 2.8 VILL A ---- d 4.5 4.4 -8.7 1.0 1.0 -2.7 WES2 A ---- d -2.7 4.4 2.8 -.2 .5 .3 WSRT A ---- d .3 1.8 -4.9 .0 .4 -1.2 WTZR A ---- d 1.5 .1 2.2 .3 .0 .5 YAR1 A ---- d .4 4.9 -6.1 .1 .9 -1.8 YELL A ---- d -2.0 -1.5 -.3 -.2 -.2 .2 ZWEN A ---- d -2.1 .6 -14.3 -.4 .1 -3.6 Obs. Mean .4 .0 .0 .1 .0 .0 Mean Std. 3.5 3.5 12.5 .7 .7 2.8 R.M.S. 3.5 3.5 12.4 .7 .7 2.8 Table 4.3 Residuals (IGS2000 minus IGS97). --------- Code Pt Soln d d. Lat d. Lon d. Hei d.VLat d.VLon d.VHei (mm) (mm) (mm) (mm/y) (mm/y) (mm/y) ALGO A ---- d -1.0 -.3 .3 -.2 -.1 .1 AUCK A ---- d .4 .6 -5.4 .1 .2 -1.4 BAHR A ---- d 1.5 4.1 5.3 .4 1.2 1.6 BRMU A ---- d -.6 -1.4 -2.1 -.1 -.4 -.6 CAS1 A ---- d -2.4 .2 13.2 -.6 .0 3.4 CHAT A ---- d .3 .7 -5.5 .1 .2 -1.4 DAV1 A ---- d -2.5 -.6 6.5 -.7 -.2 1.6 DRAO A ---- d 1.9 1.4 .6 .5 .3 .1 FAIR A ---- d -.2 1.1 5.8 .0 .3 1.4 FORT A ---- d -3.5 1.8 -9.9 -.9 .4 -2.5 GODE A ---- d .3 -2.0 3.7 .1 -.5 .9 GOL2 A ---- d 1.3 -5.2 4.1 .3 -1.3 1.1 GRAZ A ---- d 1.5 -.5 7.9 .4 -.1 2.2 GUAM A ---- d -.1 -.8 -6.3 .0 -.1 -1.6 HOB2 A ---- d -1.4 -.5 9.4 -.4 -.1 2.8 IRKT A ---- d 1.5 -.1 9.7 .4 -.1 2.5 KERG A ---- d -.9 -3.2 -6.9 -.3 -.8 -1.8 KIT3 A ---- d -1.1 -2.7 1.3 -.2 -.7 .2 KOKB A ---- d 1.8 -1.5 -3.4 .5 -.4 -.9 KOUR A ---- d -3.3 -4.3 -11.4 -.8 -1.0 -3.0 KWJ1 A ---- d .3 1.6 -7.2 .1 .4 -1.9 LHAS A ---- d .6 -4.8 -16.7 .1 -1.3 -4.6 MAC1 A ---- d 2.6 .7 -2.8 .7 .2 -.8 MALI A ---- d -3.9 7.4 5.5 -1.0 2.1 1.7 MAS1 A ---- d 1.1 -1.8 5.6 .3 -.5 1.4 MATE A ---- d -.3 1.9 .4 -.1 .5 .0 MCM4 A ---- d -.8 .3 8.8 -.2 .1 2.2 MDO1 A ---- d 1.9 .6 6.9 .5 .1 1.8 NLIB A ---- d 1.2 1.0 -3.8 .3 .2 -1.1 NYAL A ---- d .8 .7 -9.5 .2 .1 -2.5 OHIG A ---- d -1.3 -4.2 -3.1 -.4 -1.0 -1.0 ONSA A ---- d 1.1 .4 6.1 .3 .1 1.6 PERT A ---- d .6 -1.8 -10.3 .1 -.5 -2.6 PIE1 A ---- d 2.6 .4 6.0 .6 .1 1.6 POTS A ---- d .3 .2 2.6 .1 .0 .7 SANT A ---- d -.4 4.4 -4.7 -.1 1.1 -1.3 SHAO A ---- d -.5 1.1 1.9 -.1 .3 .3 THU1 A ---- d -1.4 -1.4 4.2 -.4 -.4 1.0 TIDB A ---- d -1.3 -2.2 7.2 -.3 -.5 2.0 TROM A ---- d .7 2.9 -14.3 .2 .5 -3.2 TSKB A ---- d 4.0 6.3 -6.6 1.0 1.7 -1.8 VILL A ---- d 1.8 .8 -3.3 .4 .2 -.8 WES2 A ---- d -1.9 -1.6 -2.8 -.4 -.5 -.8 WSRT A ---- d 1.6 -.1 5.9 .4 .0 1.9 WTZR A ---- d .8 -.1 2.7 .2 .0 .6 YAR1 A ---- d .9 -1.8 1.7 .2 -.5 .4 YELL A ---- d -2.0 1.5 1.2 -.5 .4 .3 ZWEN A ---- d -1.4 -.6 1.3 -.4 -.2 .2 Obs. Mean .0 .0 .0 .0 .0 .0 Mean Std. 1.7 2.5 6.8 .4 .7 1.8 R.M.S. 1.7 2.5 6.7 .4 .6 1.8 5) Comparison to plate model NUVEL1-A The horizontal estimated station velocity for the ITRF and IGS solutions are compared to the NNR-NUVEL1A pllate motion model. The vertical component is included in the tables below; it is compared to the implicit "zero" vertical motion in the model. The quality of the horizontal comparison is fairly stable between the two ITRF frames (Table 5.1). Some stations are known not to follow any plate motion model in their area (e.g.: GUAM), or being affected by plate boundary "distortions" (e.g.: SANT). If we assume that overall the average vertical plate motion should average "zero", then the ITRF2000/IGS2000 vertical velocity field show some RMS improvements. The level of improvement and current quality appears to be better with the IGS realization. Table 5.1 ITRF97 & ITRF2000 minus NNR-NUVEL1A --------- ITRF97 - NNR-NUVEL1A ITRF2000 - NNR-NUVEL1A ---------------------- ---------------------- Code Pt Soln d d.VLat d.VLon d.VHei d.VLat d.VLon d.VHei (mm/y) (mm/y) (mm/y) (mm/y) (mm/y) (mm/y) ALGO A ---- d -3.3 .5 .9 -1.8 .4 2.4 AREQ A ---- d 1.9 14.2 2.7 ASC1 A ---- d -1.0 .8 -2.6 AUCK A ---- d -1.2 1.0 3.1 1.1 -.9 3.1 BAHR A ---- d -6.2 2.5 2.2 -7.1 .8 .5 BRAZ A ---- d -3.7 -1.0 -8.8 BRMU A ---- d -2.2 .8 .8 -.3 .2 -.2 CAS1 A ---- d -3.5 1.1 10.5 -.9 .6 3.7 CEDU A ---- d -.4 .0 6.7 CHAT A ---- d -.5 1.0 1.2 .5 -.9 2.6 DAV1 A ---- d -4.2 .4 5.7 -2.0 .7 4.3 DGAR A ---- d 19.9 23.7 2.6 DRAO A ---- d -.5 2.5 1.6 1.0 1.8 1.3 FAIR A ---- d -3.6 2.1 .0 -2.4 1.5 .4 FORT A ---- d -1.8 1.5 1.8 .5 1.2 1.0 GODE A ---- d -2.2 .4 -.3 -.8 .6 -1.9 GOL2 A ---- d 5.0 -3.8 -.8 6.5 -4.9 -1.3 GRAZ A ---- d .4 .8 -1.5 1.4 1.1 -2.3 GUAM A ---- d 16.6 -28.0 1.0 18.3 -31.4 3.3 HARK A ---- d -3.2 -2.2 2.7 HOB2 A ---- d -1.3 2.5 1.7 1.0 1.0 1.3 HRAO A ---- d -2.2 -2.6 .4 IRKT A ---- d .7 3.5 .6 1.1 1.9 -.1 KERG A ---- d -4.6 -.1 8.6 -1.9 -.4 5.0 KIT3 A ---- d 3.3 3.6 1.2 3.8 2.0 -1.5 KOKB A ---- d -1.1 -2.7 .7 .2 -4.1 -.9 KOSG A ---- d .1 -1.4 .3 KOUR A ---- d -.9 2.6 1.5 .9 1.4 2.6 KWJ1 A ---- d -3.2 -2.1 -4.1 -.5 -4.9 -1.8 LHAS A ---- d 20.5 21.6 2.5 20.4 21.4 .1 LPGS A ---- d .7 .2 1.1 MAC1 A ---- d -19.1 -2.0 3.6 -18.0 -5.8 .3 MALI A ---- d -4.0 -3.0 -13.1 -1.7 -3.5 -5.5 MAS1 A ---- d -3.1 -1.2 .1 -.8 -.5 1.4 MATE A ---- d -3.2 4.3 -.5 -2.5 4.5 -1.0 MCM4 A ---- d -.1 5.0 -6.9 .0 2.2 .8 MDO1 A ---- d -1.7 .2 1.2 .0 -.2 -.6 NLIB A ---- d -1.6 1.0 -3.7 -.1 .8 -2.9 NYAL A ---- d .4 -2.9 .5 .4 -2.5 6.4 OHIG A ---- d -1.0 -1.2 13.4 .1 -2.0 9.5 ONSA A ---- d -.4 -1.4 1.5 .0 -1.4 2.6 PERT A ---- d -3.7 2.0 2.9 -1.7 1.0 .0 PIE1 A ---- d -2.2 -.2 .8 -1.1 -1.1 -.5 POTS A ---- d .3 -.2 -.7 .8 -.5 -1.3 RIOG A ---- d 1.9 1.6 5.1 SANT A ---- d 3.9 18.9 7.9 6.9 19.8 4.7 SHAO A ---- d -2.5 11.4 -1.5 -1.5 9.8 -1.5 THU1 A ---- d -2.1 -.8 -3.5 -2.0 -.2 2.2 TIDB A ---- d -1.2 2.0 .4 1.2 .7 1.4 TROM A ---- d 2.6 -4.2 -.2 2.1 -3.3 2.6 TSKB A ---- d 3.6 -10.8 -4.3 6.1 -13.4 -.5 VILL A ---- d -1.9 -.5 .7 .1 .6 -1.4 WES2 A ---- d -2.6 .4 -1.3 -1.3 .5 -1.0 WSRT A ---- d -.1 -1.0 .7 .5 -.6 .4 WTZR A ---- d .0 -.1 -2.3 .9 -.1 -.9 YAR1 A ---- d -5.3 .4 2.6 -3.2 .1 .3 YELL A ---- d -1.9 1.9 4.3 -.7 1.2 5.1 ZWEN A ---- d 2.3 -.1 -.5 2.2 -.1 -3.0 Obs. Mean -.8 .8 .7 .8 .3 1.0 Mean Std. 5.2 6.6 4.2 5.7 7.3 2.8 R.M.S. 5.2 6.6 4.2 5.7 7.3 2.8 Table 5.2 IGS97 & IGS2000 minus NNR-NUVEL1A --------- IGS97 - NNR-NUVEL1A IGS2000 - NNR-NUVEL1A ---------------------- ---------------------- Code Pt Soln d d.VLat d.VLon d.VHei d.VLat d.VLon d.VHei (mm/y) (mm/y) (mm/y) (mm/y) (mm/y) (mm/y) ALGO A ---- d -2.9 1.0 4.0 -1.6 .8 4.6 AREQ A ---- d 2.8 14.7 2.3 ASC1 A ---- d -1.7 .5 -2.9 AUCK A ---- d -.2 .3 3.9 .9 -1.2 1.3 BAHR A ---- d -8.3 1.1 -1.7 -6.8 1.8 1.3 BRAZ A ---- d -1.2 .8 2.6 BRMU A ---- d -2.1 .9 .3 -.7 .4 -.1 CAS1 A ---- d -2.2 2.1 .2 -1.4 1.0 2.3 CEDU A ---- d -.7 .7 5.8 CHAT A ---- d -.5 .2 3.2 .3 -1.1 .4 DAV1 A ---- d -3.9 1.5 2.8 -3.1 .8 3.3 DGAR A ---- d 19.7 23.6 2.2 DRAO A ---- d -.9 1.6 .4 1.2 1.3 1.0 FAIR A ---- d -3.4 2.6 -6.4 -2.2 2.0 -4.0 FORT A ---- d -1.4 .2 2.8 -.8 .6 .0 GODE A ---- d -2.1 1.9 -2.8 -.5 1.2 -1.6 GOL2 A ---- d 3.9 -5.9 -1.2 5.9 -8.0 .0 GRAZ A ---- d .3 .9 -4.5 1.4 .8 -.8 GUAM A ---- d 17.1 -30.6 3.3 18.6 -32.5 2.1 HARK A ---- d .0 -.4 6.0 HOB2 A ---- d .2 2.7 2.0 1.0 .9 3.8 HRAO A ---- d -2.1 -2.7 .1 IRKT A ---- d .2 2.7 -3.5 1.1 1.5 .6 KERG A ---- d -4.0 .8 7.3 -2.5 -.7 4.9 KIT3 A ---- d 3.2 3.1 -4.8 3.7 1.6 -2.9 KOKB A ---- d -2.3 -2.4 4.0 -.3 -4.2 3.1 KOUR A ---- d -1.2 1.9 6.4 -.5 .8 3.1 KWJ1 A ---- d -2.0 -3.7 -.7 -.4 -5.0 -2.6 LHAS A ---- d 19.1 23.0 .1 20.3 20.5 -3.0 LPGS A ---- d -.3 .8 2.1 MAC1 A ---- d -19.5 -4.6 3.0 -17.9 -6.0 .9 MALI A ---- d -3.2 -2.8 -2.2 -2.5 -1.2 .1 MAS1 A ---- d -2.1 -.3 -.5 -.5 -.8 1.7 MATE A ---- d -3.4 4.9 -.7 -2.7 5.3 .7 MCM4 A ---- d -.3 3.2 2.6 -.4 2.1 3.2 MDO1 A ---- d -2.5 -.1 -3.5 -.4 -.7 -1.8 NLIB A ---- d -2.3 .5 -.8 -.4 .3 -1.5 NYAL A ---- d 1.6 -2.3 8.0 1.7 -1.7 7.0 OHIG A ---- d .3 -.9 10.0 .1 -1.5 7.3 ONSA A ---- d .0 -1.6 -3.8 .7 -1.3 -.6 PERT A ---- d -3.6 3.2 1.7 -1.8 1.2 -1.3 PIE1 A ---- d -3.6 .3 -.9 -1.3 -.3 .7 POTS A ---- d .3 -.7 -3.7 1.0 -.6 -1.5 RIOG A ---- d 1.7 1.2 3.8 SANT A ---- d 4.9 20.3 6.0 5.6 21.4 3.3 SHAO A ---- d -2.2 9.7 -2.1 -1.2 8.6 -.6 THU1 A ---- d -2.5 -.7 .0 -1.9 -.7 2.4 TIDB A ---- d .5 3.1 1.7 1.5 .8 2.8 TROM A ---- d 2.1 -2.5 3.2 2.3 -1.7 1.6 TSKB A ---- d 5.5 -13.5 .7 7.6 -13.4 -.1 VILL A ---- d -1.4 .6 -1.0 .0 .9 -.6 WES2 A ---- d -2.2 .9 1.3 -1.2 .3 1.0 WSRT A ---- d -.2 -.5 -3.2 .9 -.4 .2 WTZR A ---- d .2 .0 -1.9 1.1 .0 .2 YAR1 A ---- d -5.6 2.8 -2.6 -3.7 .7 -2.5 YELL A ---- d -1.9 1.0 4.1 -1.0 .9 5.2 ZWEN A ---- d 1.7 .5 -5.2 1.6 .2 -3.3 Obs. Mean -.6 .8 .7 .7 .4 1.0 Mean Std. 5.3 7.1 3.6 5.7 7.5 2.6 R.M.S. 5.2 7.1 3.7 5.7 7.4 2.8 6) ERP's The expected effect on the pole position is: XP(2000) + R Y = XP(97) YP(2000) + R X = YP(97) Where: R X = 0.024 mas +- 0.055 mas R Y = 0.004 mas +- 0.061 mas Those rotations have been propagated to GPS week 1143 (01/12/02). 7) Summary The sections above provides the details of the analysis done for the proposed IGS2000 (IGS00) realixation of ITRF2000. The station set used went from 51 to 54. The implementation epoch is tentatively set for GPS week 1143 (01/12/02). IGS97 to IGS2000 station changes: - Removed: BRAZ, AREQ, - Added: ASC1, CEDU, DGAR, LPGS, RIOG. IGS2000 to IGS97 transformation (epoch 1998.0): Parameter Estimate Formal Sigma Normalized R X (mas) : .04039 .05332 0.8 R Y (mas) : -.00144 .05957 0.0 R Z (mas) : .04268 .03586 1.2 T X (m) : .00600 .00253 2.4 T Y (m) : .00561 .00327 1.7 T Z (m) : -.02007 .00508 -4.0 * SCL (ppb) : 1.40332 .12066 11.6 * d R X (mas/y) : -.00422 .03800 -0.1 d R Y (mas/y) : .00133 .03998 0.0 d R Z (mas/y) : .02960 .03366 0.9 d T X (m/y) : -.00038 .00165 -0.2 d T Y (m/y) : -.00083 .00193 -0.4 d T Z (m/y) : -.00152 .00277 -0.5 d SCL (ppb/y) : .01215 .12191 0.1