============================================================================= INTERNATIONAL GNSS SERVICE CODE Analysis Strategy Summary ============================================================================= Analysis Center | Center for Orbit Determination in Europe (CODE) | Astronomical Institute | University of Bern | Sidlerstrasse 5 | CH-3012 Bern | Switzerland | E-mail: code (at) aiub.unibe.ch (CODE AC Team) | Phone: +41-31-631-8591 | Fax: +41-31-631-3869 | Data archive: ftp://ftp.unibe.ch/aiub/CODE/ | http://www.aiub.unibe.ch/download/CODE/ | Web: http://www.aiub.unibe.ch (CODE at AIUB) | http://www.bernese.unibe.ch (Bernese SW) ----------------------------------------------------------------------------- Contact People | Dr. Stefan Schaer | E-mail: stefan.schaer (at) aiub.unibe.ch | Phone: +41-31-631-8592 (8591) | Dr. Rolf Dach | E-mail: rolf.dach (at) aiub.unibe.ch | Phone: +41-31-631-8593 (8591) | Michael Meindl | E-mail: michael.meindl (at) aiub.unibe.ch | Phone: +41-31-631-3802 (8591) | Dr. Heike Bock | E-mail: heike.bock (at) aiub.unibe.ch | Phone: +41-31-631-8602 (8591) | Dr. Adrian Jaeggi | E-mail: adrian.jaeggi (at) aiub.unibe.ch | Phone: +41-31-631-8592 (8591) | Luca Ostini | E-mail: luca.ostini (at) aiub.unibe.ch | Phone: +41-31-631-3802 (8591) ----------------------------------------------------------------------------- Software Used | Bernese GPS Software Version 5.1, developed at AIUB ----------------------------------------------------------------------------- List of CODE's | ftp://ftp.unibe.ch/aiub/BSWUSER50/TXT/AIUB_AFTP.README analysis products | http://www.aiub.unibe.ch/download/BSWUSER50/TXT/AIUB_AFTP.README | Final Products | CODwwwwn.EPH GNSS/GPS ephemeris/clock data in 7 daily generated for | files at 15-min intervals in SP3 format, GPS week 'wwww' | including accuracy codes computed from day of week 'n' | a long-arc analysis (n=0,1,...,6) | CODwwww7.ERP GNSS ERP (pole, UT1-UTC) solution for 1 day of year 'ddd' | week in IGS IERS ERP format year 'yy' | CODwwww7.SUM Analysis summary for 1 week | CODwwww7.SNX GNSS weekly station coordinates, SATAs, | GCs, and daily sets of ERPs in SINEX | format | CODwwwwn.CLK GPS satellite and receiver clock | corrections at 30-sec intervals in clock | RINEX format | CODwwwwn.CLK_05S GPS satellite and receiver clock | corrections at 5-sec intervals in clock | RINEX format | CODwwwwn.TRO GNSS 2-hour troposphere delay estimates | in troposphere SINEX format | CODGddd0.yyI GNSS 2-hour global ionosphere maps in | IONEX format, including satellite and | receiver P1-P2 code bias values | CGIMddd0.yyN GNSS daily Klobuchar-style ionospheric | (alpha and beta) coefficients in RINEX | format | P1P2yymm.DCB GNSS monthly P1-P2 code bias solutions | in Bernese DCB format | P1C1yymm.DCB/F GPS monthly P1-C1 code bias solutions in | Bernese DCB format and in a format | specific to the CC2NONCC utility | | Remarks: | | EPH: Orbit positions correspond to the estimates for | the middle day of a 3-day long-arc analysis. | ERP: ERP representation is continuous in time (over | 1 week). | CLK: Clock corrections are consistent with carrier | phase as well as P1/P2 pseudorange measurements. | CODE P1-C1 pseudorange bias values of a moving | 30-day solution are considered to correct C1/X2 | and C1/P2 receiver data. | EPH/ERP/TRO: These products are based on weekly | coordinate results. | Rapid Products | CODwwwwn.EPH_R GNSS/GPS ephemeris/clock data in at generated daily | 15-min intervals in SP3 format, including | accuracy codes computed from a long-arc | analysis | CODwwwwn.ERP_R GNSS ERP (pole, UT1-UTC) solution in IGS | IERS ERP format | CODwwwwn.CLK_R GPS satellite and receiver clock | corrections at 30-sec intervals in clock | RINEX format | CODwwwwn.TRO_R GNSS 2-hour troposphere delay estimates | in troposphere SINEX format | CORGddd0.yyI GNSS 2-hour global ionosphere maps in | IONEX format, including satellite and | receiver P1-P2 code bias values | CGIMddd0.yyN_R GNSS daily Klobuchar-style ionospheric | (alpha and beta) coefficients in RINEX | format | CODwwwwd.SNX_R GNSS daily station coordinates and set | of 6-hourly ERPs in SINEX format (for | IERS inter-technique combination) | | Remarks: | | EPH: Orbit positions correspond to the estimates for | the last day of a 3-day long-arc analysis. | CLK: Clock corrections are consistent with carrier | phase as well as P1/P2 pseudorange measurements. | CODE P1-C1 pseudorange bias values of a moving | 30-day solution are considered to correct C1/X2 | and C1/P2 receiver data. | Ultra Rapid | COD.EPH_U GNSS ephemeris/broadcast clock data in at Products updated | 15-min ntervals in SP3 format, including every 6 hours | accuracy codes computed from a long-arc | analysis | COD.ERP_U GNSS ERP (pole, UT1-UTC) solution in IGS | IERS ERP format | COD.SUM_U List of considered GNSS stations | COD.TRO_U GNSS 2-hour troposphere delay estimates | in troposphere SINEX format | COD.ION_U GNSS 2-hour global ionosphere maps in | Bernese ION format | | Remarks: | | EPH: Orbit positions correspond to the estimates for | the last 24 hours of a 3-day long-arc analysis | plus predictions for the following 24 hours | EPH/ERP/TRO: Files contain generally results of last | update | ION: Last rapid ionosphere product complemented by all | available ionosphere predictions | Predictions | CODwwwwn.EPH_Pi GNSS/GPS ephemeris/clock data at 15-min updated every 6 | intervals in SP3 format, including hours | accuracy codes computed from a long-arc | analysis | CODwwwwn.ERP_Pi GNSS ERP (pole, UT1-UTC) solution in IGS | IERS ERP format | COPGddd0.yyI GNSS 2-hour global ionosphere maps in | IONEX format, including satellite P1-P2 | code bias values | CGIMddd0.yyN_Pi GNSS daily Klobuchar-style ionospheric | (alpha and beta) coefficients in RINEX | format | CODwwwwd.EPH_5D GNSS/GPS ephemeris/clock data at 15-min | intervals in SP3 format | CODwwwwd.ERP_5D GNSS ERP (pole, UT1-UTC) solution in IGS | IERS ERP format | | Remarks: | | "P2" indicates 2-day predictions (24-48 hours); "P" | indicates 1-day predictions (0-24 hours). | "5D" indicates files containing predicted information | for 5 days (0-120 hours). | Specialties in | - CODE has been generating its products from a rigorous CODE's analysis | combination of GPS and GLONASS observations. In this | way, best possible consistency of the orbit products is | guaranteed. | - Uninterrupted POD for all transmitting GNSS satellites, | specifically for: | . brand new satellites | . satellites without any broadcast orbit information | . satellites marked unhealthy/unusable | . poorly observed (GLONASS) satellites | . (GPS) satellites being repositioned | - Elevation mask angle of 3 degrees used. | - Sophisticated ambiguity resolution scheme, already | including GLONASS ambiguity resolution for shortest | baselines. | - Continuous parameterization, particularly for EOP, | troposphere ZPD and horizontal gradient parameters, | ionosphere parameters, allowing for connection of the | parameters at day boundaries. | - IGS fiducial sites are automatically verified for | consistent datum definition. This is also true with | respect to all antenna-sharing fiducial sites. | - Inclusion of fast moving South Pole station AMU2. | - Inclusion of all available NGA stations. | - Generation of high-rate (5-sec) clock products. | - Generation of high-rate (1-hour) EOP results | (internally). | - Setup of GNSS satellite antenna PCV parameters specific | to each individual GPS and GLONASS satellite; | corresponding patterns are not only available for the | ionosphere-free linear combination but also for the | geometry-free (L1-L2) linear combination. | - A multi-GNSS-capable internal PCV file format is used; | receiver antenna PCV models specific to GLONASS | (or other) frequencies could be applied. | - Monitoring of various differential code biases (DCBs), | specifically: | . GPS/GLONASS P1-P2 satellite and receiver DCBs | . GPS P1-C1 satellite DCBs | . biases crucial for GLONASS ambiguity resolution | - Extensive monitoring of IGS data flow concerning: | . availability | . latency | . completeness | . consistency | - Provision of GNSS geocenter coordinates in SINEX. | - Production of GNSS rapid SINEX files containing station | coordinates and ERPs with a time resolution of 6 hours | is foreseen as a contribution for the IERS inter- | technique combination. | - Regular GNSS orbit validation using SLR data; CODE | acts as an AAC of the ILRS. | - The latest version of our steadily further developed | GNSS analysis SW is employed for operational analysis. | Computer platform | Week 1477: UBELIX: Linux, x86_64 | Week 1065: UBECX: SunOS | Last changes | Week 1477: See IGSREPORT.16225 and IGSMAIL.5771 | Week 1452: See IGSREPORT.15669/IGSREPORT.14622 | Week 1440: See IGSREPORT.15405 | Week 1439: See IGSREPORT.15403 | Week 1409: See IGSREPORT.14695 | Week 1406: See IGSREPORT.14622 and IGSMAIL.5507/IGSMAIL.5518 | Week 1400: See IGSREPORT.14486 and IGSMAIL.5518 | Week 1367: See IGSREPORT.13669 | Week 1349: See IGSREPORT.13201 | Week 1328: See IGSREPORT.12706 | Week 1326: See IGSREPORT.12657 | Week 1321: See IGSREPORT.12569 and IGSMAIL.5151 | Week 1299: See IGSREPORT.12031 | Week 1282: See IGSREPORT.11617 | Week 1279: See IGSREPORT.11543 | Week 1255: See IGSMAIL.4913 | Week 1254: See IGSREPORT.10997 and IGLOSMAIL.963 | Week 1252: See IGSMAIL.4782 | Week 1242: See IGSREPORT.10752 | Week 1222: See IGSREPORT.10361 and IGSMAIL.4474/IGLOSMAIL.770 | Week 1216: See IGSMAIL.4371/IGLOSMAIL.736 | Week 1191: See IGSREPORT.9756 and IGSMAIL.4162 | Week 1158: See IGSREPORT.9147 and IGSMAIL.3823 | Week 1143: See IGSREPORT.8868 | Week 1142: See IGSREPORT.8848 | Week 1135: See IGSREPORT.8710 | Week 1130: See IGSREPORT.8616 | Week 1128: See IGSREPORT.8577 | Week 1077: See IGSREPORT.7544 | Week 1065: See IGSREPORT.7279 | Week 1057: See IGSREPORT.7107 and IGSMAIL.2827 | Week 1021: See IGSREPORT.6351 | Week 0978: See IGSREPORT.5415 and IGSMAIL.2043 | Week 0947: See IGSREPORT.4698 and IGSMAIL.1829 | Week 0926: See IGSREPORT.4247 and IGSMAIL.1705 | Week 0873: See IGSREPORT.3056 ----------------------------------------------------------------------------- Preparation Date | 18-Aug-1996 ----------------------------------------------------------------------------- Modification Dates| 13-Mar-1998 | 12-Mar-2002/SS: Major revision and update | 13-Mar-2002/SS: JGM3 model up to degree 12 | 24-Oct-2002/SS: Typo concerning satellite antenna offset | value corrected | 28-May-2008/SS/RD: Major revision and update ----------------------------------------------------------------------------- Effective Date for| 27-Apr-2008 Data Analysis | ============================================================================= ----------------------------------------------------------------------------- | MEASUREMENT MODELS | |---------------------------------------------------------------------------| | Preprocessing | Phase preprocessing in a baseline by baseline mode | | | using triple-differences. In most cases, cycle slips | | | are fixed looking simultaneously at different linear | | | combinations of L1 and L2. If a cycle slip cannot be | | | fixed reliably, bad data points are removed or new | | | ambiguities are set up. In addition, a data screening | | | step on the basis of weighted postfit residuals is | | | performed. Outliers are removed. | |---------------------------------------------------------------------------| | Basic Observable | GPS/GLONASS carrier phase; code only used for receiver | | | clock synchronization | | |--------------------------------------------------------| | | Elevation angle cutoff : 3 degrees | | | Sampling rate : 3 minutes | | | Weighting : 6 mm for double-differenced | | | ionosphere-free phase | | | observations at zenith; | | | elevation-dependent weighting | | | function 1/cos(z)**2 | |---------------------------------------------------------------------------| | Modeled | Double differences, ionosphere-free linear combination | | observable | | |---------------------------------------------------------------------------| | RHC phase | Phase polarization effects applied (Wu et al., 1993) | | rotation corr. | | |---------------------------------------------------------------------------| | Ground antenna | IGS05 PCV model is applied. Receiver antenna PCV | | phase center | models specific to GLONASS is applied (as soon as | | calibrations | available). | |---------------------------------------------------------------------------| | Troposphere | A priori model : Saastamoinen-based hydrostatic | | | (using GPT) mapped with the dry-GMF | | |--------------------------------------------------------| | | Met data input : No real met measurements used (GPT) | | |--------------------------------------------------------| | | Estimation : Zenith delay corrections are | | | estimated relying on the wet-GMF in | | | intervals of 2 hours. N-S and E-W | | | horizontal delay parameters are | | | solved for every 24 hours. Details | | | about the gradient model can be | | | found in (Rothacher et al., 1997). | | | Refined gradient model used (see | | | IGSMAIL.5518). | | |--------------------------------------------------------| | | Constraints : Both zenith and gradient parameters | | | are treated as completely | | | unconstrained. | | |--------------------------------------------------------| | | Mapping function: GMF | |---------------------------------------------------------------------------| | Ionosphere | Not modeled (first-order effect eliminated by forming | | | the ionosphere-free linear combination of L1 and L2). | | | GNSS-derived global ionosphere map information is used | | | to support ambiguity resolution when using the QIF | | | strategy. | | | | | | Zero-difference data analysis for global ionosphere | | | mapping and for P1-P2 code bias retrieval: | | | | | | The vertical total electron content (VTEC) is modeled | | | in a solar-geomagnetic reference frame using a | | | spherical harmonics expansion up to degree and | | | order 15. The time resolution considered for the VTEC | | | maps is 2 hours. Instrumental biases, so-called | | | differential code biases (DCB), for all GNSS | | | satellites and ground stations are estimated as | | | constant values for each day, simultaneously with the | | | 12 times 256, or 3072 parameters used to represent the | | | global VTEC distribution. The DCB datum is defined by | | | a zero-mean condition imposed on the satellite bias | | | estimates. To convert line-of-sight TEC into vertical | | | TEC, a modified single-layer model mapping function | | | approximating the JPL extended slab model mapping | | | function is adopted. The mapping function is evaluated | | | at geodetic satellite elevation angles. For the | | | computation of the ionospheric pierce points, a | | | spherical layer with a radius of 6821 km is assumed, | | | implying geocentric, not geodetic IONEX latitudes. | | | The geometry-free linear combination of one-way | | | carrier phase leveled to code is used as observable. | | | | | | Elevation cutoff: 10 degrees | |---------------------------------------------------------------------------| | Plate motions | IGS05 station velocities | |---------------------------------------------------------------------------| | Tidal | Solid earth tidal displacement: complete model from | | displacements | IERS Conventions 2003 | | | Permanent tidal term : applied in tide model, | | | NOT included in site | | | coordinates | | | | | | Step 1: in-phase: degree 2 and 3 | | | Nominal h02 and l02 : 0.6078, 0.0847 (anela.)| | | Nominal h22 and l22 :-0.0006, 0.0002 | | | Nominal h3 and l3 : 0.292 , 0.015 | | | | | | out-of-phase: degree 2 only semi- and diurnal | | | diurnal: nominal hI, lI :-0.0025,-0.0007 | | | semi-di: nominal hI, lI :-0.0022,-0.0007 | | | | | | latitude dependence | | | diurnal: nominal l1 : 0.0012 | | | semi-di: nominal l1 : 0.0024 | | | | | | Step 2: in-phase: degree 2, diurnal | | | in-phase and out-of-phase: long-period tides | | |--------------------------------------------------------| | | Pole tide : applied (IERS, 2003) | | | nominal mean m1, m2 : 0.033, 0.331 arcsec. | | |--------------------------------------------------------| | | Ocean tidal loading: FES2004 | |---------------------------------------------------------------------------| | Atmospheric load.| Not applied | |---------------------------------------------------------------------------| | Earth orientation| Tidal UT1 (> 5 days): modeled | | models (EOP) | Subdaily ERPs : IERS2003 | | | Nutation : IAU2000 | | | Precession : USNO Circular No. 163 | |---------------------------------------------------------------------------| | Satellite center | IGS05 PCV model applied. | | of mass | | | correction | | |---------------------------------------------------------------------------| | Satellite phase | IGS05 PCV model applied. | | center calibrat. | | ----------------------------------------------------------------------------- | Relativity | Periodic, -2(R*V/c): applied | | corrections | Gravity bending : not applied | | | Dynamical : applied (IERS, 2003) | | | Shapiro : applied | ----------------------------------------------------------------------------- | Time argument | TDT | ----------------------------------------------------------------------------- | GNSS attitude | Not applied | | model | | ----------------------------------------------------------------------------- ----------------------------------------------------------------------------- | ORBIT MODELS | |---------------------------------------------------------------------------| | Geopotential | JGM3 model up to degree and order 12 (+C21+S21) | | |--------------------------------------------------------| | | GM = 398600.4415 km**3/sec**2 | | |--------------------------------------------------------| | | AE = 6378.1363 km | |---------------------------------------------------------------------------| | Third-body | Sun and Moon as point masses | | |--------------------------------------------------------| | | Ephemeris: JPL DE405 | | |--------------------------------------------------------| | | GMsun = 132712500000 km**3/sec**2 | | |--------------------------------------------------------| | | GMmoon = 4902.7890 km**3/sec**2 | |---------------------------------------------------------------------------| | Solar radiation | Direct radiation: CODE RPR model coefficients | | pressure | (updated 2007) | | |--------------------------------------------------------| | | Estimated RPR parameters (see Beutler 1994): | | | Constants in D-, Y- and X-direction | | | Periodic terms in X-direction | | |--------------------------------------------------------| | | Earth shadow model includes: cylindric shadow | | |--------------------------------------------------------| | | Moon shadow model includes: umbra and penumbra | | |--------------------------------------------------------| | | Reflection radiation: not included | | |--------------------------------------------------------| | | New GPS satellite attitude model: not applied | |---------------------------------------------------------------------------| | Tidal forces | Solid earth tides: TIDE2000 (IERS 2000) | | |--------------------------------------------------------| | | Ocean tides: OT CSR30 model | |---------------------------------------------------------------------------| | Relativity | Applied (IERS 2003) | |---------------------------------------------------------------------------| | Numerical | Integration algorithms developed at AIUB by Gerhard | | Integration | Beutler (see references below). Representation of the | | | the orbit by a polynomial of degree 10 for 1 hour. | | |--------------------------------------------------------| | | Integration step: 1 hour | | |--------------------------------------------------------| | | Starter procedure: no special starter procedure needed | | |--------------------------------------------------------| | | Arc length: 72 hours | ----------------------------------------------------------------------------- ----------------------------------------------------------------------------- | ESTIMATED PARAMETERS (APRIORI VALUES & SIGMAS) | |---------------------------------------------------------------------------| | Adjustment | Weighted least-squares algorithms | |---------------------------------------------------------------------------| | Station | Starting with GPS week 1400, the IGS realization of | | coordinates | ITRF2005 (IGS05) is used. | | | | | | Notes: | | | | | | Number of GNSS stations typically included: | | | . 200 for final analysis | | | . 120 for rapid analysis | | | . 90 for ultra-rapid analysis | | | Datum definition: | | | . 3 no-net translation conditions | | | . 3 no-net rotation conditions | | | . geocenter coordinates constrained nominally to | | | zero values | | | IGS05 fiducial sites are selected as reference, if: | | | . horizontal deviation < 10 mm | | | . vertical deviation < 30 mm | | | List of selected/rejected fiducial sites is given in | | | CODE's weekly analysis summary files. | |---------------------------------------------------------------------------| | Satellite clock | Zero-difference data analysis for GPS clock estimation | | bias | and for P1-C1 code bias retrieval: | | | | | | Satellite and receiver clock corrections are computed | | | on the basis of the double-difference orbit, ERP, | | | coordinate, and troposphere solutions. The generation | | | of high-rate clock results is performed in the | | | following three steps: | | | 1 Least-squares adjustment with a sampling of 5 min | | | using phase and code observations. | | | 2 Interpolation from 5 min to 30 sec using phase. | | | 3 Interpolation from 30 sec to 5 sec using phase | | | (using IGS 1-Hz observation data). | | | | | | These clock corrections are consistent with carrier | | | phase as well as P1/P2 pseudorange measurements. CODE | | | P1-C1 pseudorange bias values of a moving 30-day | | | solution are considered to correct C1/X2 and C1/P2 | | | receiver data. | | | | | | Note: Daily sets of P1-C1 code bias values for the | | | satellite constellation are derived as part of the | | | global clock estimation process by distinguishing | | | between three receiver classes. | | | | | | Elevation cutoff: 5 degrees | |---------------------------------------------------------------------------| | Receiver clock | See above (Satellite clock biases) | | bias | | |---------------------------------------------------------------------------| | Orbital | 6 Keplerian elements plus 5 solar radiation parameters | | parameters | at start of arc; no a priori sigmas used. | | | Estimated RPR parameters (see Beutler 1994): | | | - Constants in D-, Y- and X-direction | | | - Periodic terms in X-direction | | | A priori orbits are the CODE rapid orbit solution. | | | Pseudo-stochastic orbit parameters (small velocity | | | changes), every 12 hours, constrained to: | | | . 1.E-6 m/sec in radial | | | . 1.E-5 m/sec in along-track | | | . 1.E-8 m/sec in out-of-plane | |---------------------------------------------------------------------------| | Troposphere | Zenith delay parameters and pairs of horizontal delay | | | gradient parameters are estimated for each station in | | | intervals of 2 hours and 24 hours. No a priori | | | constraints are applied. Piece-wise, linear | | | parameterization, allowing for connection of the | | | parameters at day boundaries. | |---------------------------------------------------------------------------| | Ionospheric | Not estimated in ionosphere-free analyses | | correction | | |---------------------------------------------------------------------------| | Ambiguity | Ambiguities are resolved in a baseline-by-baseline | | | mode performing the following steps: | | | . Melbourne-Wuebbena approach (< 6000 km) | | | . Quasi-Ionosphere-Free (QIF) approach (< 2000 km) | | | . Phase-based widelane/narrowlane method (< 200 km) | | | . Direct L1/L2 method, also for GLONASS (< 20 km) | | | GNSS-derived global ionosphere map information is used | | | to support the code-less methods. | |---------------------------------------------------------------------------| | Earth Orient. | X- and Y-pole coordinates, and UT1-UTC are represented | | Parameters (EOP) | each with piece-wise linear polynomials which are | | | continuous in time. UT1-UTC is fixed to the a priori | | | value at the beginning of the first day. No further | | | a priori sigmas are used. | | | | | | All reported CODE EOP solutions do include a subdaily | | | EOP model (see above). The estimates therefore | | | correspond to daily averages on top of the introduced | | | a priori model. | | | | | | Drifts in nutation (Dpsi, Deps) are solved for in a | | | special 3-day solution. The corresponding nutation | | | parameters generally set up are constrained to the | | | IAU 2000 model for the CODE official solution. | | | | | | High-rate (1-hour) X-, Y- and UT1-UTC estimates are | | | also generated in a special 3-day solution. | |---------------------------------------------------------------------------| | GNSS attitude | Not estimated | | model | | |---------------------------------------------------------------------------| | Other | Center of mass coordinates: | | parameters | | | | Center of mass, or geocenter coordinate parameters are | | | commonly set up as part of each solution. The related | | | parameters are usually heavily constrained to zero | | | values. Additional computations on the normal equation | | | level are made regularly in order to retrieve 1-day, | | | 3-day, as well as weekly GNSS geocenter coordinates in | | | the current ITRF. | | | | | | GNSS satellite phase center offsets and patterns: | | | | | | Corresponding parameters are commonly set up as part | | | of each final solution for each individual GNSS | | | satellite. The related parameters are usually heavily | | | constrained to the corresponding nominal values (as | | | defined by the IGS05 PCV model). Such GNSS PCV | | | parameters are available for the ionosphere-free as | | | well as the geometry-free linear combination. | ----------------------------------------------------------------------------- ----------------------------------------------------------------------------- | REFERENCE FRAMES | |---------------------------------------------------------------------------| | Inertial | Geocentric; mean equator and equinox of 2000 Jan 1 | | | at 12:00 (J2000.0) | |---------------------------------------------------------------------------| | Terrestrial | IGS05 station coordinates and velocities | |---------------------------------------------------------------------------| | Interconnection | Precession: IAU 2000 Precession Theory | | |--------------------------------------------------------| | | Nutation: IAU 2000 Nutation Theory | | |--------------------------------------------------------| | | Relationship between UT1 and GMST: USNO Circular | | | No. 163 (IAU Resolution) | | |--------------------------------------------------------| | | Tidal variations in UT1: periods > 5.8 days modeled | | | but not removed (UT1-UTC sol.)| ----------------------------------------------------------------------------- REFERENCES: Beutler, G. (1990), Numerische Integration gewoehnlicher Differential- gleichungssysteme: Prinzipien und Algorithmen. Mitteilungen der Satelliten-Beobachtungsstation Zimmerwald, No. 23, Druckerei der Universitaet Bern, 1990. Beutler, G., E. Brockmann, W. Gurtner, U. Hugentobler, L. Mervart, and M. Rothacher (1994), Extended Orbit Modeling Techniques at the CODE Processing Center of the International GPS Service for Geodynamics (IGS): Theory and Initial Results, Manuscripta Geodaetica, 19, 367-386, April 1994. Boehm, J., A. Niell, P. Tregoning, H. Schuh (2006), Global Mapping Function (GMF): A new empirical mapping function based on numerical weather model data. Geophys. Res. Lett., 33. Boehm, J., R. Hinkelmann, H. Schuh (2007), A global model of pressure and temperature for geodetic applications. Journal of Geodesy, Vol. 81, pp. 679-683. Dach, R., U. Hugentobler, P. Fridez, M. Meindl (eds.) (2007), Documentation of the Bernese GPS Software Version 5.0, January 2007. Fliegel, H., T. Gallini and E. Swift (1992), Global Positioning System radiation force model for geodetic applications. J.Geophys.Res. 97(B1), pp. 559-568, January 1992. McCarthy, D.D., G. Petit (eds.) (2000), IERS Conventions (2000). McCarthy, D.D., G. Petit (eds.) (2003), IERS Conventions (2003). IERS Technical Note 32, Observatoire de Paris, October 2003. Rothacher, M., T.A. Springer, S. Schaer, G. Beutler (1997), Processing Strategies for Regional GPS Networks, IAG Symposia, Vol. 118, pp. 93-100. Schaer, S. (1999), Mapping and Predicting the Earth's Ionosphere Using the Global Positioning System, Geodaetisch-geophysikalische Arbeiten in der Schweiz, Vol. 59. Wu, J.T., S.C. Wu, G.A. Hajj, W.I. Bertiger, S.M. Lichten (1993), Effects of antenna orientation on GPS carrier phase. Manuscripta Geodaetica 18, 1993, pp. 91-98.