aus00001.eops.txt

 Technical description of solution aus00001

 1. Purpose of solution:  Session EOP

 2. Analysis Center: GEOSCIENCE AUSTRALIA (AUS)

 3. Short narrative description of solution:

 Observational VLBI time delays ( NEOS-A) since 07-Feb-1983
 have been analyzed for this solution. Reductional model is
 realised in accordance with IERS Conventions (2000) except
 recommended precession/nutation model.
 Celestial reference frame was fixed to ICRF'2000 (Ext.1).
 Terrestrial reference frame was fixed to ITRF'2000. Associated
 velocity field is used for station coordinates calculation.
 All parameters under estimation have been adjusted using Kalman
 filter technique. Station Wettzell is used as clock reference
 station when available on default. Tropospheric gradients have
 been considered as constant parameters.

 4.  Estimated parameters:

     a. celestial frame:  No

     b. terrestrial frame:  No

     c. Earth orientation:  X, Y, UT1-UTC, dpsi, deps

     d. zenith troposphere:  Random walk process

     e. troposphere gradients:  No estimated before 1992;
                      Estimates as a constant parameters after 1992

     f. station clocks:  Offset as a random walk process, rate as a
                constant except sessions when the clock rate is
                considered as a random walk process for separate
                stations

     g. baseline clocks:  No

     h. other:  No

 5.  Celestial reference frame:

     a. a priori source positions:  ICRF'2000

     b. source positions adjusted in solution:  No

     e. solution identification or reference:  ICRF'2000

 6 - Terrestrial reference frame:

     a. a priori station positions:  ITRF'2000

     b. a priori station velocities:  ITRF'2000 velocity field

     c. reference epoch:  1997.0

     d. station positions/velocities adjusted in solution:  No

     l. solution identification or reference:  ITRF'2000

 7.  Earth orientation:

     a. a priori precession model:  IAU(1976)

     b. a priori nutation model:  IAU(1980)

     c. a priori short-period tidal variations in x, y, UT1:
            IERS Conventions (2000) - model by R.Eanes

     d. EOP estimation:  X, Y, UT1-UTC, dpsi, deps   every
                         session

 8.  A priori geophysical models:

     a. troposphere: Niell mapping function for dry and wet delays

     b. solid Earth tide:  IERS Conventions 2000, except
                           re-instating for permanent tides.

     c. ocean loading:  IERS Conventions 2000

     d. atmosphere loading: time series of local deformation due to
                      atmospheric loading provided by H.-G. Scherneck

 9.  Data type:  delays

 10. Data editing:  Only data with zero quality flag in NGS format are used

 11. Data weighting:
     Observations with elevation less than 5 degrees to be divided by
     sin(elevation).  Observations with elevation more than 5
     degrees are not weighted as a rule, but Kalman filter
     approach checks a quality of every observation and
     downweights it in case of bad result.

 12. Standard errors reported:  Formal errors are derived from
     Kalman filter adjustment

 13  Software:  OCCAM 5.0

 14. Other information: New station TIGO in chile has the 
     following apriori coordinates in the ITRF200 for initial 
     epoch 1997.0 

   X =  1492054.057 
   Y = -4887961.035 
   Z = -3803541.441   


 ----------------------------------------------------------------------
 Dr. Oleg A.Titov                        Tel:     +61-2-62014361
 Project officer                         Fax:     +61-2-62014366

 Geoscience Australia
 PO Box 2, Belconnen, ACT, 2616, Australia

 e-mail: OlegTitov@auslig.gov.au