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ANALYSIS CENTRE   | IAC/MCC, Information and Analysis Center of Navigation /
                  | Mission Control Center
                  | 141070, Russia, Koroliov of Moscow reg, Pionerskaya str.  4
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CONTACT PERSON(S) | Vladimir Mitrikas       e-mail : Vladimir.Mitrikas@mcc.rsa.ru
                  |                           Tel. : +7-095-5135817
                  |                           Fax. : +7-095-5868380
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SOFTWARE USED     | STARK, POLAR, developed by MCC
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FINAL IGS PRODUCTS| IACwwwwd.sp3   GLONASS ephemeris/clock files in 7 daily 
files
GENERATED FOR     |                at 15 min intervals in sp3 format,
GPS WEEK 'wwww'   |                including accuracy codes
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PREPARATION DATE  |  June 14, 2005
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|                     MEASUREMENT MODELS 
|
|---------------------------------------------------------------------------|
| Preprocessing    | Pass selection based on lenght. Cycle slip detection 
|
|                  | and correction performed in two steps: using different 
|
|                  | combinations for each station and then processing all 
|
|                  | double-differences. 
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|---------------------------------------------------------------------------|
| Basic Observable | carrier phase and pseudo range 
|
| 
|--------------------------------------------------------|
|                  | elevation angle cutoff : 12 degrees 
|
|                  | sampling rates         : 30 sec. (preprocessing) 
|
|                  |                           5 min. (orbit determination) 
|
|                  |                           5 min. (clock estimation) 
|
|                  | weighting              : 1 cm for carrier phase, 
|
|                  |                        : 2  m for pseudorange 
|
|---------------------------------------------------------------------------|
| Modelled         | Independent ionospheric-free undifferenced carrier 
|
| observable       | phase and pseudorange observations. 
|
|---------------------------------------------------------------------------|
| RHC phase        | applied in preprocessing 
|
| rotation corr.   | 
|
|---------------------------------------------------------------------------|
| Ground antenna   | Elevation dependent following the IGS_01 model 
|
| phase centre cal.| 
|
|---------------------------------------------------------------------------|
| Troposphere      | Niell model with estimated Zenith delay every 6 hours 
|
|                  | as linear functions 
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|---------------------------------------------------------------------------|
| Ionosphere       | ionospheric free combinations used 
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|---------------------------------------------------------------------------|
| Plate motions    | ITRF2000 station velocities fixed when available, NNR- 
|
|                  | Nuvel otherwise 
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|---------------------------------------------------------------------------|
| Tidal            | Solid earth tidal displacement: IERS2000 model 
|
| displacements 
|--------------------------------------------------------|
|                  | Pole tide:  applied IERS2000 model 
|
| 
|--------------------------------------------------------|
|                  | Ocean loading: OSO coefficients 
|
|---------------------------------------------------------------------------|
| Atmospheric load.| not applied 
|
|---------------------------------------------------------------------------|
| Satellite center | Block I x,y & z: (0.210, 0, 0.854m) 
|
| of mass 
|--------------------------------------------------------|
| correction       | Block II/IIA x,y & z :(0.279, 0, 1.023m) 
|
| 
|--------------------------------------------------------|
|                  | Block IIR    x,y & z :(0.000, 0, 0.000m) 
|
| 
|--------------------------------------------------------|
|                  | GLONASS      x,y & z :(0, 0, 1.620m) 
|
| 
|--------------------------------------------------------|
|                  | GLONASS-M    x,y & z :(-0.545, 0, 2.183m) 
|
|---------------------------------------------------------------------------|
| Satellite phase  | not applied 
|
| centre calibrat. | 
|
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|                           ORBIT MODELS 
|
|---------------------------------------------------------------------------|
| Geopotential     | EGM-96 up to degree and order 12 
|
| 
|--------------------------------------------------------|
|                  | GM=398600.4415  km**3/sec**2 
|
|---------------------------------------------------------------------------|
| Third-body       | Sun, Moon and Jupiter 
|
|                  | regarded as point masses 
|
| 
|--------------------------------------------------------|
|                  | indirect C20 effect due to Moon 
|
| 
|--------------------------------------------------------|
|                  | ephemeris: JPL DE403 
|
| 
|--------------------------------------------------------|
|                  | GMsun = 132712439370.0 km**3/sec**2 
|
| 
|--------------------------------------------------------|
|                  | GMmoon = 4902.799184 km**3/sec**2 
|
|---------------------------------------------------------------------------|
| Solar radiation  | direct radiation: ROCK4, ROCK42 and T30 approximations 
|
| pressure         |                   denoted as T10, T20 and T30 for 
|
|                  |                   Block I, II and IIR satellites, 
resp.|
| 
|--------------------------------------------------------|
|                  | one scale factor and one y-bias estimated per arc 
|
| 
|--------------------------------------------------------|
|                  | Earth shadow model : conic without penumbra 
|
| 
|--------------------------------------------------------|
|                  | reflection radiation:  included 
|
|---------------------------------------------------------------------------|
| Tidal forces     | solid earth tides: IERS2000 Standards 
|
| 
|--------------------------------------------------------|
|                  | Ocean tides: IERS2000 Standards recomendations 
|
|---------------------------------------------------------------------------|
| Relativity       | applied only to clock estimates 
|
|---------------------------------------------------------------------------|
| Time argument    | TDT 
|
|---------------------------------------------------------------------------|
| Numerical        | Everhard of order 15 
|
| Integration 
|--------------------------------------------------------|
|                  | integration step: 30 minutes 
|
| 
|--------------------------------------------------------|
|                  | arc length final orbits: 48 hours ( 18 + 6 + 24 ) 
|
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|                    ESTIMATED PARAMETERS (APRIORI VALUES & SIGMAS) 
|
|---------------------------------------------------------------------------|
| Adjustment       | Weighted least-squares with estimation of time 
|
|                  | dependent parameters on every iteration 
|
|---------------------------------------------------------------------------|
| Station          | ITRF2000 core stations constrained with 100 cm, the 
|
| coordinates      | remaining stations estimated without apriori sigmas. 
|
|                  | ITRF2000 velocities used if availalable, otherwise 
|
|                  | Nuvel-NNR. 
|
|                  | Typically 50-55 stations included. 
|
|---------------------------------------------------------------------------|
| Orbital          | Initial position and velocity, solar radiaton pressure 
|
| parameters       | scale factor and y-bias estimated as constant through 
|
|                  | the orbital arc without constrains 
|
|                  | Two cycle per revolution empirical accelerations. 
|
|---------------------------------------------------------------------------|
| Troposphere      | Zenith delays estimated as 6-hours linear functions. 
|
|---------------------------------------------------------------------------|
| Ionospheric      | no parameters estimated 
|
| correction       | 
|
|---------------------------------------------------------------------------|
| Ambiguity        | estimated as real values, one for every continuous 
|
|                  | pass between cycle slips. 
|
|---------------------------------------------------------------------------|
| ERP              | Fixed to IERS Bulletin A values 
|
|---------------------------------------------------------------------------|
| Satellite clock  | Solved for every epoch. No L1-L2 satellite calibration 
|
|---------------------------------------------------------------------------|
| Receiver clock   | Solved for every epoch. No P1-P2 receiver calibration 
|
| bias             | One station clocks (usually ONSA) aligned to GPS time 
|
|                  | is used as the reference. 
|
|---------------------------------------------------------------------------|
| Other            | Manoeuvres are detected in the preprocessing. 
|
| parameters       | Additional pseudo-pulses are adjusted once per 6 hours 
|
|                  | if needed. 
|
|                  | GLONASS to GPS time delays estimated for the combined 
|
|                  | receivers. Composite GLONASS to GPS delay is fixed to 
|
|                  | the initial value adjusted to GLONASS time scale in 
|
|                  | preprocessing 
|
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|                       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 
|
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