============================================================================= INTERNATIONAL LASER RANGING SERVICE YOUR ORGANIZATION NAME AND ACRONYM HERE Analysis Strategy Summary ============================================================================= ANALYSIS CENTRE | Hitotsubashi University | 2-1 Naka, | Kunitachi, Tokyo 186-8601 Japan ----------------------------------------------------------------------------- CONTACT PERSONS | Toshimichi Otsubo, otsubo@srv.cc.hit-u.ac.jp ----------------------------------------------------------------------------- SOFTWARE USED | concerto ver 4.10 ----------------------------------------------------------------------------- ILRS PRODUCTS | Daily QC report for a number of satellites | ----------------------------------------------------------------------------- PREPARATION DATE | 30 Nov 2007 ============================================================================= ----------------------------------------------------------------------------- | MEASUREMENT MODELS | |---------------------------------------------------------------------------| | Satellites used | AJISAI, STARLETTE, STELLA, JASON-1, ERS-2, ENVISAT, | | | LAGEOS-1, LAGEOS-2, ETALON-1, ETALON-2, GPS-35, GPS-36,| | | GLONASS-95, GLONASS-99, GLONASS-102 | |---------------------------------------------------------------------------| | Basic measurement| Satellite Laser Ranging (SLR): round-trip travel time | | |--------------------------------------------------------| | | speed of light : 299792458 m/s | | | wavelength : 532.0, 423.0, 847.0 & 694.3 nm| | | elevation angle cutoff : not applied | | | weighting : 5 cm to 2 m (4 levels) | | | range biases & time biases : | | | not modeled/estimated in orbit determination, | | | pass-by-pass estimation in residual analysis | | | tropospheric biases : not modeled/estimated | |---------------------------------------------------------------------------| | Data editing | 3.0 sigma editing | |---------------------------------------------------------------------------| | Troposphere | Marini & Murray model | |---------------------------------------------------------------------------| | Ionosphere | not modeled/estimated | |---------------------------------------------------------------------------| | Relativity | scale: LET (TT time scale) | | | effects: light time corrections | |---------------------------------------------------------------------------| | Satellite center | AJISAI: 1010 mm, | | of mass | STARLETTE and STELLA: 75 mm, | | | LAGEOS: 251 mm, ETALON: 558 mm, | | | other LEOs and GNSSes: ILRS Website | |---------------------------------------------------------------------------| | Other | | |---------------------------------------------------------------------------| ----------------------------------------------------------------------------- | ORBIT MODELS | |---------------------------------------------------------------------------| | Geopotential | GGM02C(static terms through degree and order 10 to 80) | | | (C(2,0), C(2,1) and S(2,1) time dependent) | | |--------------------------------------------------------| | | Constants | | | AE = 6378136.6 m | | | 1/F = 298.25642 | | | GM = 3.986004415 x 10^14 m3/s2 | |---------------------------------------------------------------------------| | Third-body | planets: | | | Mercury, Venus, Earth Moon, Mars, Jupiter, Saturn, | | | Uranus, Neptune | | |--------------------------------------------------------| | | ephemeris: JPL DE405 | |---------------------------------------------------------------------------| | Solar radiation | IERS Conventions 2003 | | pressure | | | | direct radiation : applied | | | albedo radiation : not applied | | | earth thermal radiation : not applied | | |--------------------------------------------------------| | | Earth shadow model includes: penumbra | | |--------------------------------------------------------| | | reemitted radiation: not applied | |---------------------------------------------------------------------------| | satellite | modeled | | thermal thrust | estimation of empirical (constant and once-per-rev) | | | along-track and (once-per-rev) cross-track | | | accelerations | |---------------------------------------------------------------------------| | Tidal forces | solid earth tides: IERS 2003 Conventions model | | |--------------------------------------------------------| | | Ocean tides: CSR 1996 | |---------------------------------------------------------------------------| | Atmospheric | not modeled/estimated | | gravitational | | | attraction | | |---------------------------------------------------------------------------| | Dynamic | applied, IERS Conventions 2003 | | polar motion | | |---------------------------------------------------------------------------| | Relativity | point-mass accelerations, Lense-Thirring effect, | | | coriolis force | |---------------------------------------------------------------------------| | Numerical | Cowell 12th order predictor-corrector | | integration |--------------------------------------------------------| | | integration step: | | | LEO: 15 to 20 s | | | LAGEOS: 60 s | | | ETALON and GNSSes: 120 s | | |--------------------------------------------------------| | | arc length (orbits): | | | LEO: 2 d | | | LAGEOS: 7 d | | | ETALON and GNSSes: 14 d | ----------------------------------------------------------------------------- ----------------------------------------------------------------------------- | ESTIMATED PARAMETERS (APRIORI VALUES & SIGMAS) | |---------------------------------------------------------------------------| | Adjustment | weighted least-squares adjustment | |---------------------------------------------------------------------------| | Orbital | Initial position and velocity: | | parameters | estimated for each satellite (unconstrained) | | | Solar radiaton pressure: CR (fixed at 1.13 for LAGEOS) | | | Empirical accelerations (unconstrained) | |---------------------------------------------------------------------------| | Stations | definition: SLR monument (eccentricities subtracted), | | | at mean epoch of each arc | | | fixed to ITRF2000 + some our own updates | |---------------------------------------------------------------------------| | Troposphere | not estimated | |---------------------------------------------------------------------------| | EOP | fixed to finals2000A.all at USNO (IERS Rapid Service | | | Prediction Center) | |---------------------------------------------------------------------------| | Range biases | fixed to zero | |---------------------------------------------------------------------------| | Constraints | not applied | |---------------------------------------------------------------------------| ----------------------------------------------------------------------------- | REFERENCE FRAMES | |---------------------------------------------------------------------------| | Inertial | J2000.0 | |---------------------------------------------------------------------------| | Terrestrial | ITRF2000 (a priori station coordinates) | | | ITRF2000 (station velocities) | | | solid earth tide: IERS 2003 Conventions | | | ocean loading: NAO99.b | | | atmospheric pressure loading: not modeled/estimated | | | geocenter motion: not modeled | | | geocenter tidal frequencies: not applied | | | pole tide: IERS 2003 Conventions | | | origin: C(1,0) = C(1,1) = S(1,1) = 0 | |---------------------------------------------------------------------------| | Interconnection | Precession: IERS Conventions 2003 | | |--------------------------------------------------------| | | Nutation: IAU 2000A | | |--------------------------------------------------------| | | Celestial pole: IERS 2003 Conventions | | |--------------------------------------------------------| | | Earth Orientation Parameters: fixed to finals2000A.all | | |--------------------------------------------------------| | | Tidal variations in UT1 and PM: IERS 2003 Conventions | ----------------------------------------------------------------------------- ----------------------------------------------------------------------------- | OTHER INFORMATION | |---------------------------------------------------------------------------| | | | |---------------------------------------------------------------------------|