============================================================================= INTERNATIONAL LASER RANGING SERVICE YOUR ORGANIZATION NAME AND ACRONYM HERE Analysis Strategy Summary ============================================================================= ANALYSIS CENTRE | IAC/MCC, Information and Analysis Center of Navigation / | Mission Control Center | 141070, Russia, Koroliov of Moscow reg,Pionerskaya str. 4 ----------------------------------------------------------------------------- CONTACT PERSONS | Vladimir Glotov, Michail Zinkovsky | e-mail : vladimir.glotov@mcc.rsa.ru | Tel./Fax.: +7-095-5135075 | Vladimir Mitrikas e-mail :vladimir.mitrikas@mcc.rsa.ru | | Tel. : +7-095-5135817 | Fax. : +7-095-5868380 ----------------------------------------------------------------------------- SOFTWARE USED | STARK, POLAR, developed by MCC ----------------------------------------------------------------------------- ILRS PRODUCTS | mccwwwwd.sp3, mccwwww7.sum GLONASS ephemeris Generated for GPS | Week 'wwww' | Daily EOP ----------------------------------------------------------------------------- PREPARATION DATE | EOP since 1994 | GLONASS ephemeris since 1995, as ILRS products since 1998 ============================================================================= ----------------------------------------------------------------------------- | MEASUREMENT MODELS | |---------------------------------------------------------------------------| | Satellites used | GLONASS, LAGEOS-1, LAGEOS-2 | | | | |---------------------------------------------------------------------------| | 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 : 0 degrees | | | weighting : from 0.05 m to 1.0 m | | | range biases : estimated for some stations | | | time biases : not modeled/estimated | | | tropospheric biases : not modeled/estimated | |---------------------------------------------------------------------------| | Data editing | own technique (polynom and median) | |---------------------------------------------------------------------------| | Troposphere | Marini-Murrey model | |---------------------------------------------------------------------------| | Ionosphere | not modeled/estimated | |---------------------------------------------------------------------------| | Relativity | not modeled | |---------------------------------------------------------------------------| | | | | Satellite center | LAGEOS: 0.251 m | | of mass |--------------------------------------------------------| | correction | | | |--------------------------------------------------------| | |--------------------------------------------------------| | | GLONASS x,y & z :( -1.570m, 0, 0) | | |--------------------------------------------------------| | | GLONASS-M x,y & z :(-1.9016m, 0.137m, 0) | |---------------------------------------------------------------------------| ----------------------------------------------------------------------------- | ORBIT MODELS | |---------------------------------------------------------------------------| | Geopotential | EGM96 up to degree and order 70 | | |--------------------------------------------------------| | | Constants | | | AE = 6378.1363 km | | | GM = 398600.4415 km3/s2 | |---------------------------------------------------------------------------| | Third-body | Sun, Moon and Jupiter | | | regarded as point masses | | |--------------------------------------------------------| | | ephemeris: JPL DE403 | |---------------------------------------------------------------------------| | Solar radiation | IERS2000 Standards | | pressure | | | | direct radiation : applied | | | albedo radiation : applied | | | earth thermal radiation : not applied | | |--------------------------------------------------------| | | Earth shadow model includes: conic without penumbra | | | | | |--------------------------------------------------------| | | reflection radiation: included | |---------------------------------------------------------------------------| | satellite | not modeled | |---------------------------------------------------------------------------| | Tidal forces | solid earth tides: IERS 2000 Standards | | |--------------------------------------------------------| | | Ocean tides: IERS 2000 Standards recommendations | |---------------------------------------------------------------------------| | Atmospheric | not modeled/estimated | | gravitational | | | attraction | | |---------------------------------------------------------------------------| | Dynamic | applied | | polar motion | | |---------------------------------------------------------------------------| | Relativity | not modeled | |---------------------------------------------------------------------------| | Numerical | Everhard of order 15 | | integration |--------------------------------------------------------| | | integration step: L: 500 s, G: 30 min | | |--------------------------------------------------------| | | arc length (orbits): L: 3 days G: 8 days | ----------------------------------------------------------------------------- ----------------------------------------------------------------------------- | ESTIMATED PARAMETERS (APRIORI VALUES & SIGMAS) | |---------------------------------------------------------------------------| | Adjustment | Weighted least-squares with estimation of time | | | dependent parameters on every iteration | |---------------------------------------------------------------------------| | Orbital | Initial position and velocity: | | parameters | estimated for each satellite (unconstrained) | | | Solar radiaton pressure: CR kept fixed at 1.13 | | | Empirical accelerations (unconstrained) | |---------------------------------------------------------------------------| | Stations | definition: SLR monument (eccentricities subtracted), | | | at mean epoch of each arc | | | a priori values: ITRF2000 | |---------------------------------------------------------------------------| | Troposphere | not estimated | |---------------------------------------------------------------------------| | EOP | definition: x-pole, y-pole and LOD | | | epoch: at noon of each day | | | frequency: daily | | | a priori values: IERS 05 C04 | |---------------------------------------------------------------------------| | Range biases | for some (non-core) stations | | | a priori value: 0 m | |---------------------------------------------------------------------------| | Constraints | loose constraints | |---------------------------------------------------------------------------| ----------------------------------------------------------------------------- | REFERENCE FRAMES | |---------------------------------------------------------------------------| | Inertial | Geocentric; mean equator and equinox of 2000 Jan 1 | | | at 12:00 (J2000.0) | |---------------------------------------------------------------------------| | Terrestrial | ITRF2000 reference frame realized through the set of | | | core station coordinates and velocities. | |---------------------------------------------------------------------------| | Interconnection | Precession: IAU 1976 Precession Theory | | |--------------------------------------------------------| | | Nutation: IAU 1980 Nutation Theory | | |--------------------------------------------------------| | | Celestial pole offsets from IERS Bulletin A | | |--------------------------------------------------------| | | Relationship between UT1 and GMST: Aoki et al. (1982) | | |--------------------------------------------------------| | | ERP interpolated from IERS Bulletin A (updated twice a | | | week) | | |--------------------------------------------------------| | | Tidal variations in UT1 and PM: IERS Standards | -----------------------------------------------------------------------------