Technical description of solution bkg2010a_dsnx
1. Purpose of solution: 24 hours session solution for IVS time series of baseline lengths
and basis solution for combination techniques
2 - Analysis Center: Federal Agency for Cartography and Geodesy (BKG Leipzig)
3. Short narrative description of solution:
All available dual-band Mark III/IV/V observations from 1984 on were analysed for this
solution. The orientation of CRF is defined by the a priori source positions of ICRF2.
All source coordinates are estimated with a constraint of 10**(-8) rad. The TRF is defined by
no-net-translation and rotation constraints for the coordinates of all sites in a VLBI session
related to VTRF2008a except for AIRA, CHICHI10, CTVASTJ, DSS13, TIGOCONC, YEBES40M.
The values of the official list of VLBI antenna axis offsets issued by the
IVS Analysis Coordinator (http://vlbi.geod.uni-bonn.de/IVS-AC/Conventions/antenna-info.txt,
update 2009-03-16) were used.
Mean pole coordinates used for computation of pole tide deformation were
applied according to IERS Conventions 2003 (eq. 23a, 23b).
The Vienna mapping function (VMF1) is applied for troposphere correction modelling.
The atmospheric pressure loading time series provided by the Goddard VLBI group
which are available on the Web at http://lacerta.gsfc.nasa.gov/aplo (Petrov & Boy, 2004) are used.
A priori short-period tidal variations in EOP were taken into account in accordance with IERS
Conventions 2003. Ocean loading model FES2004 computed by H. G. Scherneck was used.
Thermal expansion modelling developed by A. Nothnagel was used
(http://vlbi.geod.uni-bonn.de/IVS-AC/Conventions/antenna-info.txt).
The values of station eccentricities were taken from the official IVS-table ECCDAT.ecc.
4. Estimated parameters:
a. celestial frame: right ascension, declination
b. terrestrial frame: X, Y, Z
c. Earth orientation: X-pole, Y-pole, UT1-TAI, Xdot, Ydot, UT1dot,
X-nutation, Y-nutation
d. zenith troposphere: 1h piece-wise linear functions,
rate constraint generally 50 ps/hour,
VMF1 wet partial derivative (segmented)
e. troposphere gradient: east and north offset,
offset constraint 0.5 mm,
rate constraint 2.0 mm/day
f. station clocks: 1h piece-wise linear functions,
rate constraint generally 5.E-14
g. baseline clocks: set in initial analysis - usually used
h. other: No
5. Celestial reference frame:
a. a priori source positions: ICRF2
b. source positions adjusted in solution: yes
6 - Terrestrial reference frame:
a. a priori station positions: VTRF2008a
b. a priori station velocities: VTRF2008a
c. reference epoch: 2000.0
d. station positions adjusted in solution: yes
e. definition of origin, orientation, and their time evolution:
no-net-translation and no-net-rotation of position with respect to
VTRF2008a for all stations of the VLBI session except
AIRA, CHICHI10, CTVASTJ, DSS13, TIGOCONC, YEBES40M
7. Earth orientation:
a. a priori precession/nutation model: IAU2000A Precession-Nutation,
IERS 2003 implementation, modified using the IAU2006
precession model
b. a priori short-period tidal variations in X, Y and UT1 due to short
period tidal and nutation effects were applied as recommended in the
IERS 2003 Conventions
c. a priori UT1 and polar motion: usno_finals.data
(http://gemini.gsfc.nasa.gov/solve_save/usno_finals.erp)
8. A priori geophysical models:
a. troposphere: VMF1 mapping function (dry+wet), Saastamoinen
zenith delay calculated using logged pressure and temperature
b. solid Earth tide: IERS 2003 Conventions
c. ocean loading: FES2004 model
d. pole tides: IERS 2003 Conventions
e. atmosphere loading: atmospheric pressure loading time series provided by GSFC
(available at http://lacerta.gsfc.nasa.gov/aplo/aplo_bds.tar.bz2)
f. antenna thermal deformation: IVS antenna thermal deformation model of Nothnagel 2008
g. axis offsets: values of the official list of VLBI antenna axis offsets issued by the
IVS Analysis Coordinator (http://vlbi.geod.uni-bonn.de/IVS-AC/Conventions/antenna-info.txt)
9. Data type: Group delays
10. Data editing: 5 deg elevation cutoff,
editing of outliers during adjustment when necessary.
11. Data weighting: Observations are weighted using std reported
in observational files; re-weighting iteration for each session
to achieve the chi-square unity.
12. Standard errors reported: Reported formal errors are derived from
least-squares estimation propagated from data uncertainties and
weighted as discussed in #11.
13 Software: Calc 10, SOLVE release: 2010.05.21
References:
L. Petrov, J.-P. Boy, Study of the atmospheric pressure loading signal in VLBI observations,
Journal of Geophysical Research, 10.1029/2003JB002500, Vol. 109, No. B03405, 2004.
Axel Nothnagel (2008) Short Note: Conventions on thermal expansion
modelling of radio telescopes for geodetic and astrometric VLBI;
Journal of Geodesy, DOI: 10.1007/s00190-008-0284-z.
Appendix A.
-----------
>>> FORMAT DESCRIPTION <<<
>>> ################## <<<
Sinex output implementation in the VLBI Analysis software system Calc/Solve
Leonid Petrov
2003.04.22
Abstract
This document describes the way how Calc/Solve writes down a listing
of a VLBI solution in Sinex format.
Questions and comments about this guide should be sent to:
Leonid Petrov ( Leonid.Petrov@lpetrov.net )
Table of contents:
1 ................ Overview
2 ................ Deviations from the SINEX 1.00 standard
2.1 ........... New block SOLUTION/CONSTRAINT_EQUATION_INFO
2.2 ........... New block SOLUTION/CONSTRAINT_EQUATION_MATRIX
2.3 ........... New block SOLUTION/CONSTRAINT_EQUATION_VECTOR
2.4 ........... New block SOLUTION/CONSTRAINT_WEIGHT_MATRIX
2.5 ........... New block SOLUTION/DECOMPOSED_NORMAL_MATRIX BLOCK
2.6 ........... New block SOLUTION/DECOMPOSED_NORMAL_VECTOR BLOCK
2.7 ........... New block NUTATION/DATA
2.8 ........... New block PRECESSION/DATA
2.9 ........... New block SOURCE/ID
3 ................ Implementation in Solve
3.1 ........... Syntax of INCLUDE_PARAM and EXCLUDE_PARAM lists
3.2 ........... Examples of INCLUDE_PARAM and EXCLUDE_PARAM lists
3.3 ........... Treatment of station with discontinuous motion
3.4 ........... Restrictions
________________________________________________________________________________
1 Overview
==========
SINEX stands for "Solution INdependent EXchange format". This format was
developed by Blewitt et al. (1994)
http://www.dgfi.badw-muenchen.de/gps/sinex.html and
http://alpha.fesg.tu-muenchen.de/iers/sinex/sinex_v2_appendix1.pdf
for facilitating the task of combining several GPS solutions. Original
design of Sinex format was made for solving this specific task. However,
later this format evolved towards to a common machine-readable form of
solution listings for other space geodesy techniques, VLBI and SLR, and
attempts were made for overcoming flaws of the original design. This
process of evolution is not yet completed, therefore, different software
systems implement a little bit different flavors of Sinex format.
Listings in Sinex format produced by Solve contain information about
stations, sources, estimates of the parameters, their covariance matrix,
constraint equation, right-hand side of constraint equations and weight
matrix of constraint equations. In addition to these results, a portion of
the decomposed normal matrix and normal vector can be included in the
listing as well. A user has control which blocks should be included in the
listing. The current implementation of the Sinex format does not allow
to include in the listing any parameter which was solved for. Only
some type of parameters, like station position, EOP, etc can be included.
However, a user has total control which parameters among the parameters
of the supported type are to be included or not included in the listing.
2 Deviations from the SINEX 1.00 standard
=========================================
Solve currently writes listing in Sinex 2.10 format. Deviations from
the Sinex 1.00 standard are as follows:
1) Eight new blocks were added:
SOLUTION/CONSTRAINT_EQUATION_INFO
SOLUTION/CONSTRAINT_EQUATION_MATRIX
SOLUTION/CONSTRAINT_EQUATION_VECTOR
SOLUTION/CONSTRAINT_WEIGHT_MATRIX
The purpose of these four blocks is to overcome the flaw of original
design of Sinex format and provide complete information about all
constraints used in the solution.
SOLUTION/DECOMPOSED_NORMAL_MATRIX
SOLUTION/DECOMPOSED_NORMAL_VECTOR
The purpose of these blocks is to provide information about transformed
normal equations before applying constraints. NB: one of the three items:
covariance matrix, constraint equations and decomposed normal equations is
redundant: having two of them one can derive the third one.
NUTATION/DATA
PRECESSION/DATA
The purpose of this section is to provide information about used
nutation/precession model and to define parameter "estimates of nutation
angles".
2) SOLUTION/STATISTICS block has new items:
WEIGHTED SQUARE SUM OF O-C sum { y(T) * w * y }
WRMS OF POSTFIT RESIDUALS sum { (A*e - y)(T) * w * (A*e - y) )/Sp ( w )
where y -- the difference between the observed time delay and theoretical;
A -- matrix of equations of conditions;
e -- vector of the parameter adjustments;
w -- weight matrix;
Sp -- stands for the mathematical operation of computing trace of
a matrix: the sum of diagnoal elements.
Summing is done over all observations used in parameter estimation.
Comment: field WEIGHTED SQUARE SUM OF O-C is not computed in global mode.
Meaning of other parameters:
NUMBER OF OBSERVATIONS totaml number of used observables
NUMBER OF UNKNOWNS total number of unknowns, including those,
which are not shown in the Sinex listing
SQUARE SUM OF RESIDUALS (VTPV) sum { (A*e - y)(T) * w * (A*e - y) )
VARIANCE FACTOR sum { (A*e - y)(T) * w * (A*e - y) )}/
( N - M - Sp( Cov(A) * B(T) * z * B ) )
where Cov(A) -- covariance matrix of the entire solution
(NB: Sinex listing may have only a portion of the solution)
B -- matrix of equations of constraints;
z -- weight matrix of contraints;
N -- total number of equations of conditions (observables);
M -- total number of unknowns.
3) The blocks which keep element of matrices do not have fields
"Second Matrix Element" and "Third Matrix Element".
The purpose of this change is to facilitate the process of creation of
the listing and to reduce significantly the probability of errors.
4) SOLUTION/MATRIX_APRIORI is not provided. The reason is that Solve does not
operate the notion of apriori covariance matrix. And it also uses singular
constraints which cannot be reduced to the form of apriori covariance matrix.
Since full information about constraints is provided in other blocks,
SOLUTION/MATRIX_APRIORI is considered as an obsolete block.
2.1 New block SOLUTION/CONSTRAINT_EQUATION_INFO
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
___________________________________________________________________
|S_O_L_U_T_I_O_N__C_O_N_S_T_R_A_I_T__I_N_F_O__B_L_O_C_K_____________|
| | | |
|__Field_________|______Description__________________|___Format_____|
| | | |
| Constraint | Row index for the constraint | 1X,I5 |
| Equation Row | equation matrix. It must match | |
| Index | the index of the constraint | |
| | equation. | |
|________________|___________________________________|______________|
| | | |
| Constraint | Identifier of the constraint | 1X,A8 |
| Equation | | |
| Identifier | | |
|________________|___________________________________|______________|
| | | |
| Constraint | Index of vector constraint. | 1X,I5 |
| Equation | 1 for scalar constraint. | |
| Sub-index | | |
| | | |
|________________|___________________________________|______________|
| | | |
| Constraint | Description of the constraint | 1X,A40 |
| Equation | | |
| Description | | |
|________________|___________________________________|______________|
This block provides description of constraint equations. Matrix of
constraint equations has dimension N_cns * N_par, where N_cns -- the number
of constraint equations, N_par -- number of estimated parameters. The first
field of the CONSTRAINT_EQUATION_INFO keeps the index of the constraint,
the second field keeps constraint identifier. Currently, the following
constraint identifiers are supported:
NNT_POS -- net rotation on station position. This vector constraint defines
three equations:
1: sum { Delta_X } = const
2: sum { Delta_Y } = const
3: sum { Delta_Y } = const
where Delta_X, Delta_Y, Delta_Z are X, Y and Z component of
the adjustment to station position.
NNR_POS -- net rotation on station position. This vector constraint defines
three equations:
1: sum { Phi_X } = const
2: sum { Phi_Y } = const
3: sum { Phi_Y } = const
where Phi_X, Phi_Y and Phi_Z are the components of the vector
of a small rotation defined as
Phi = ( r x Delta r )/ |r|^2 * R_e
here
r -- vector of station coordinate;
Delta r -- vector of adjustments to station position
R_e -- Earth's equatorial radius.
Units: dimensionless
NNT_VEL -- net rotation on station velocity. This vector constraint defines
three equations:
1: sum { Delta_X } = const
2: sum { Delta_Y } = const
3: sum { Delta_Y } = const
where Delta_X, Delta_Y, Delta_Z are X, Y and Z component of
the adjustment to station position.
NNR_VEL -- net rotation on station velocity This vector constraint defines
three equations:
1: sum { Phi_X } = const
2: sum { Phi_Y } = const
3: sum { Phi_Y } = const
where Phi_X, Phi_Y and Phi_Z are the components of the vector
of a small rotation defined as
Phi = ( r x Delta v )/ |r|^2 * R_e
here
r -- vector of station coordinates;
Delta r -- vector of adjustments to station velocity;
R_e -- Earth's equatorial radius.
Units: 1/yr
NNR_SRC -- net rotation on source coordinates
1: sum { Phi_X } = const
2: sum { Phi_Y } = const
3: sum { Phi_Y } = const
where Phi_X, Phi_Y and Phi_Z are the components of the vector
of a small rotation
EOP_XPL -- constraint on X pole coordinate
EOP_YPL -- constraint on Y pole coordinate
EOP_UT1 -- constraint on UT1 angle
EOR_XPL -- constraint on X pole rate
EOR_YPL -- constraint on Y pole rate
EOR_UT1 -- constraint on UT1 rate
VEL_U -- constraint on Up topocentric coordintate of station velocity
VEL_E -- constraint on East topocentric coordintate of station velocity
VEL_N -- constraint on North topocentric coordintate of station velocity
VEL_X -- constraint on X coordinate of station velocity
VEL_Y -- constraint on Y coordinate of station velocity
VEL_Z -- constraint on Z coordinate of station velocity
STA_U -- constraint on Up topocentric coordintate of station position
STA_E -- constraint on East topocentric coordintate of station position
STA_N -- constraint on North topocentric coordintate of station position
STA_X -- constraint on X coordinate of station position
STA_Y -- constraint on Y coordinate of station position
STA_Z -- constraint on Z coordinate of station position
BLC_VAL -- constraint on baselie clocks
DCL_ORG -- constraint on declination of the set of certain sources
GRD_OFF -- constraint on atmopshere path delay gradient offset
NUT_OFF -- constraint on offset of nutation in longitude and nutation in
obliquity
OAT_RAT -- constraint on rate of changes of atmopshere path delay
OCL_RAT -- constraint on clock drift
RAS_ORG -- constraint on right ascension of the set of certain sources
SRC_COO -- constraint on source right ascension and declination
STA_ORG -- constraint on position of certain stations
STA_TIE -- constraint on differences in position of several sites
VEL_DIR -- constraint on horizontal projection of the differences
in velocities of two stations
VEL_ORG -- constraint on velocitiess of csertain stations
VEL_SET -- constraint on linear combination of velocity components
VEL_TIE -- constraint on differences in velocities of several sites
VEL_VER -- constraint on vertial component of station velocity
Constraints on segmented paramters
STA_PWC -- constraint on site velosity in the the casewhen site position
is modeled by linear spline
GRD_RAT -- constraint on atmopshere path delay gradient rate
ATM_RAT -- constraint on atmosphere path delay rate between segments
CLO_RAT -- constraint on clock rate between segments
UT1_RAT -- constraint on UT1 rate in the case of linear spline
EOP parameterization
XPL_RAT -- constraint on X pole coordinate in the case of linear spline
EOP parameterization
YPL_RAT -- constraint on Y pole coordinate in the case of linear spline
EOP parameterization
Constraint equation subindex is 1 for scalar constraint, like EOP_XPL and
runs over components of vector constraints, like NNT_POS (1,2,3 in this
example).
2.2 New block SOLUTION/CONSTRAINT_EQUATION_MATRIX
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This block keep matrix of constraint equations. Equations are organized by
rows. Zero elements are omitted.
_____________________________________________________________________
|__S_O_L_U_T_I_O_N__C_O_N_S_T_R_A_I_T__E_Q_U_A_T_I_O_N__B_L_O_C_K_____|
| | | |
|__Field___________|______Description__________________|___Format_____|
| | | |
| Constraint | Row index for the constraint | 1X,I5 |
| equation row | equation matrix. It must match | |
| Index | the index of the constraint | |
| | equation. | |
|__________________|___________________________________|______________|
| | | |
| Constraint | Column index for the Constraint | 1X,I5 |
| equation | Equation. It must match the | |
| column index | parameter index in the | |
| | SOLUTION/ESTIMATE block for the | |
| | same parameter. | |
|__________________|___________________________________|______________|
| | | |
| Constraint | Matrix element at the location | 1X,E21.14 |
| matrix element | (row index, column index). | |
|__________________|___________________________________|______________|
2.3 New block SOLUTION/CONSTRAINT_EQUATION_VECTOR
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This block keeps the right-hand side of constraint equations.
___________________________________________________________________
|__S_O_L_U_T_I_O_N__C_O_N_S_T_R_A_I_T__V_A_L_U_E__B_L_O_C_K_________|
| | | |
|__Field_________|______Description__________________|___Format_____|
| | | |
| Constraint | Row index for the constraint | 1X,I5 |
| Equation Row | equation vector. It must match | |
| | the index of the constraint | |
| | equation. | |
|________________|___________________________________|______________|
| | | |
| Right hand | Value of right hand part of the |
| side value | constraint equation. | 1X,E21.15 |
|________________|___________________________________|______________|
| | | |
| Sigma | Reciprocal weight which is | |
| | ascribed to this constraint | 1X,E21.15 |
| | equation. | |
|________________|___________________________________|______________|
| |
| 48 |
|______________|
2.4 New block SOLUTION/CONSTRAINT_WEIGHT_MATRIX
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This block contains the elements of the weight matrix of constraint
equations. Zero elements are omitted.
______________________________________________________________________
|_____________C_O_N_S_T_R_A_I_N_T___W_E_I_G_H_T___M_A_T_R_I_X__________|
| |
|__Field__________________Description_______________________Format_____|
| | | |
| Row index of the | Row index for the weight | 1X,I5 |
| weight matrix | constraint matrix. It matches | |
| of constraint | the index of the constraint | |
| equations | equation. | |
|___________________|___________________________________|______________|
| | | |
| Column index of | Column index for the weight | 1X,I5 |
| the weight matrix | constraint matrix. It matches the | |
| of constraint | index of the constraint equation | |
| equations | | |
|___________________|___________________________________|______________|
| | | |
| Weight matrix of | Matrix element at the location | 1X,E21.14 |
| constraint | (row index, column index). | |
| equations element | | |
|___________________|___________________________________|______________|
2.5 New block SOLUTION/DECOMPOSED_NORMAL_MATRIX BLOCK
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This block contains decomposed normal equations for the subset of
parameters described in the SOLUTION/ESTIMATE block. In the case if the
SOLUTION/ESTIMATE block described all parameters adjusted in the solution,
decomposed normal matrix is equivalent to the full normal matrix. In the
case if the SOLUTION/ESTIMATE block describes only a subset of parameters,
then the decomposed normal matrix D_ii is defined as
D_ii = N_ii - N_ei(T) * (C_ee + N_ee){-1} * N_ei where
N_ii -- the block of normal matrix which corresponds to the
equations included in the SOLUTION/ESTIMATE list;
N_ee -- the block of normal matrix which corresponds to omitted
parameters;
N_ei -- the block of normal matrix which corresponds to the product
of equations of conditions of the omitted parameters and
parameters included in the SOLUTION/ESTIMATE list.
C_ee -- the block of normal matrix of constraints which corresponds
to omitted parameters;
Solve computes D_ii as D_ii = (V_ii){-1} - C_ii where
V_ii -- covariance matrix of the parameters mentioned in
SOLUTION/ESTIMATE list;
C_ii -- the block of normal matrix of constraints which corresponds
to the parameters in SOLUTION/ESTIMATE list.
It is assumed that C_ei = 0
C_ei -- the block of normal matrix of constraints which corresonds
to the product of equations of constraints of the omitted
parameters and parameters from the SOLUTION/ESTIMATE list.
___________________________________________________________________
|__S_O_L_U_T_I_O_N__D_E_C_O_M_P_O_S_E_D__N_O_R_M_A_L__M_A_T_R_I_X___|
| | | |
|__Field_________|______Description__________________|___Format_____|
| | | |
| Decomposed | Row index for the normal matrix. | 1X,I5 |
| normal matrix | It must match the parameter index | |
| row index | in the SOLUTION/ESTIMATE block | |
| | for the same parameter. | |
|________________|___________________________________|______________|
| | | |
| Decomposed | Column index for the normal matrix| 1X,I5 |
| normal matrix | It must match the parameter index | |
| column index | in the SOLUTION/ESTIMATE block | |
| | for the same parameter. | |
|________________|___________________________________|______________|
| | | |
| Decomposed | Matrix element at the location | 1X,E21.14 |
| normal matrix | (row index, column index). | |
| element | | |
|________________|___________________________________|______________|
2.6 New block SOLUTION/DECOMPOSED_NORMAL_VECTOR BLOCK
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This block contains decomposed right hand parts of normal equations for
the subset of parameters described in the SOLUTION/ESTIMATE block. In the
case if the SOLUTION/ESTIMATE block describes all parameters adjusted in
the solution, the decomposed normal vector is equivalent to the full
normal vector. In the case if the SOLUTION/ESTIMATE block describes only
a subset of parameters, then the decomposed normal vector d_i is defined as
d_i = n_i - N_ei(T) * (C_ee + N_ee){-1} * n_e where
n_i -- the block of normal vector which corresponds to the equations
listed in the SOLUTION/ESTIMATE;
n_e -- the block of the normal vector which corresponds to the
omitted parameters;
N_ee -- the block of normal matrix which corresponds to omitted
parameters;
N_ei -- the block of normal matrix which corresponds to the product
of equations of conditions of the omitted parameters and
parameters from the SOLUTION/ESTIMATE list.
C_ee -- the block of normal matrix of constraints which corresponds
to omitted parameters;
Solve computes d_i as d_i = D_i * e_i where
e_i -- vector of the estimates of the parameters from the
SOLUTION/ESTIMATE list.
___________________________________________________________________
|__S_O_L_U_T_I_O_N__D_E_C_O_M_P_O_S_E_D__N_O_R_M_A_L__V_E_C_T_O_R___|
| | | |
|__Field_________|______Description__________________|___Format_____|
| | | |
| Estimated | Index of the estimated parameter. | 1X,I5 |
| Parameter | | |
| Index | | |
| | | |
|________________|___________________________________|______________|
| | | |
| Element of | Element of the decomposed normal | 1X,E21.14 |
| decomposed | ( Row Number , Column Number ). | |
| normal vector | ( Row Number , Column Number ). | |
|________________|___________________________________|______________|
| |
| 28 |
|______________|
2.7 New block NUTATION/DATA
~~~~~~~~~~~~~~~~~~~~~~~~~~~
This block describes which apriori nutation model is used and what is the
reference model to which the nutation angles are referred.
___________________________________________________________________
|_________________N_U_T_A_T_I_O_N___D_A_T_A___L_I_N_E_______________|
| | | |
|__Field_________|______Description__________________|___Format_____|
| | | |
| [Nutat. Code] | Code for nutation reference | 1X,A8 |
| | NONE | |
| | REN2000 | |
| | IAU1980 | |
| | IERS1996 | |
| | IAU2000a | |
| | IAU2000b | |
|________________|___________________________________|______________|
| | | |
| [Nut. Usage] | Usage flag: APR or REF | 1X,A3 |
| | APR means that the previous | |
| | field kept the nutation model | |
| | used for apriori. | |
| | REF means that the previous | |
| | field kept the nutation model | |
| | used as a reference. | |
| | NONE means that the total | |
| | nutation angles are presented | |
|________________|___________________________________|______________|
| | | |
| Comments | | 1X,A66 |
|________________|___________________________________|______________|
| |
| 80 |
|______________|
2.8 New block PRECESSION/DATA
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
This block describes the apriori precession constant which was used.
___________________________________________________________________
|_________________N_U_T_A_T_I_O_N___D_A_T_A___L_I_N_E_______________|
| | | |
|__Field_________|______Description__________________|___Format_____|
| | | |
| [Prec. Code] | Code for nutation reference | 1X,A8 |
| | NONE | |
| | IAU1980 | |
| | IAU2000 | |
|________________|___________________________________|______________|
| | | |
| Comments | | 1X,A70 |
|________________|___________________________________|______________|
| |
| 80 |
|______________|
2.9 New block SOURCE/ID
~~~~~~~~~~~~~~~~~~~~~~~
___________________________________________________________________
|_____________R_A_D_I_O___S_O_U_R_C_E___D_A_T_A___L_I_N_E___________|
| | | |
|__Field_________|______Description__________________|___Format_____|
| | | |
| Source Code | Call sign for a source | 1X,A4 |
|________________|___________________________________|______________|
| | | |
| IERS name | IERS name of the radio source | 1X,A8 |
|________________|___________________________________|______________|
| | | |
| ICRF name | ICRF name of the radion source | 1X,A16 |
|________________|___________________________________|______________|
| | | |
| IAU name | IAU J2000.0 name of the radio | 1X,A10 |
| | source | |
|________________|___________________________________|______________|
| | | |
| IVS name | IVS name of the radio source | 1X,A8 |
|________________|___________________________________|______________|
| | | |
| Comments | Comments or other names of the | 1X,A29 |
| | radio source | |
|________________|___________________________________|______________|
| |
| 80 |
|______________|
3 Implementation in Solve
=========================
Solve normally produces the listing in its own so-called "spool-format".
In addition to the spool listing, Solve has a limited ability to generate
listings in Sinex format. It can write the listing in Sinex format when it
runs in batch mode. Description of the keyword Sinex in the control language
can be found in
http://gemini.gsfc.nasa.gov/solve_root/help/solve_guide_03.html#section3.13
When a user requests to apply specific constraints, Solve does not modify
normal matrix immediately. Procedures of imposing constraints collect all
constraint equation coefficients, weights, right hand part equations as well
as constraint description in an intermediate data structure. After collecting
all information about constraints Solve "applies" constraints by modifying
normal matrix and normal matrix. If a Sinex output option is specified, then
Solve passes this intermediate data structure to the routine which writes
listing down and, thus, this subroutine has access to full information about
the constraints.
Solve allows a user to specify which items among ESTIMATES, COVARIANCES,
CONSTRAINTS, DECOMPOSED_NORMAL_EQUATIONS or all of them are to be included
in the listing together with mandatory blocks. Solve allows a user to
specify which parameters are to be included in the output. Currently, Solve
does not allow to include any parameter in the listing, but only one from
the pre-defined list of supported parameter.
3.1 Syntax of INCLUDE_PARAM and EXCLUDE_PARAM lists
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
INCLUDE_PARAM and EXCLIDE_PARAM files contain the parameter lists.
List consists of one or more lines with Solve intrinsic 20-characters
long parameter names. The lines which starts from # are considered as
comments. Wild-card symbols * and ? can be included.
Solve check the name of each estimated parameter against INCLUDE_PARAM
list. If the name matches with at least one line (except comment) then
the name is flagged as "included". After that Solve check each parameter
against EXCLUDE_PARM list. If it matches with at least one line (except
comment) then it is flagged as "excluded". All parameters which are
flagged as "included" and are not flagged as "excluded" will be included
in the Sinex output.
The list of intrinsic parameter names:
Parameters which can be put in the listing in Sinex format:
ssssssss X COMPONENT X-coordinate of station position at reference epoch
ssssssss Y COMPONENT Y-coordinate of station position at reference epoch
ssssssss Z COMPONENT Z-coordinate of station position at reference epoch
ssssssss X VELOCITY X-coordinate of station velocity
ssssssss Y VELOCITY Y-coordinate of station velocity
ssssssss Z VELOCITY Z-coordinate of station velocity
ssssssss Xyymmdd-COO X-coordinate of station position at epoch yymmdd
ssssssss Yyymmdd-COO Y-coordinate of station position at epoch yymmdd
ssssssss Zyymmdd-COO Z-coordinate of station position at epoch yymmdd
ssssssss Xyymmdd-POS X-coordinate of station position at epoch yymmdd
ssssssss Yyymmdd-POS Y-coordinate of station position at epoch yymmdd
ssssssss Zyymmdd-POS Z-coordinate of station position at epoch yymmdd
ssssssss AXIS OFFSET axis offset of hte ssssssss station
X WOBBLE 0yymmddhhmm X-coordinate of pole position at epoch yymmddhhmm
X WOBBLE 1yymmddhhmm Time derivative of X pole coordinate at yymmddhhmm
Y WOBBLE 0yymmddhhmm Y-coordinate of pole position at epoch yymmddhhmm
Y WOBBLE 1yymmddhhmm Time derivative of Y pole coordinate at yymmddhhmm
UT1-TAI 0yymmddhhmm UT1 angle at epoch yymmddhhmm
UT1-TAI 1yymmddhhmm First time derivative of UT1 angle at epoch yymmddhhmm
LONGITUDE NUTATION Nutation in longitude
OBLIQUITY NUTATION Nutation in obliquity
qqqqqqqq RIGHT ASCEN Right ascension at J2000.0 epoch
qqqqqqqq DECLINATION Declination at J2000.0 epoch
qqqqqqqq RIGHT ASC V Proper motion in right ascension
qqqqqqqq DEC VELO Proper motion in declination
Other parameters which the current version of Solve cannot put in the
listing in Sinex format:
ssssssssA0yymmddhhmm Atmosphere path delay at epoch yymmddhhmm
ssssssssa0yymmddhhmm Atmosphere path delay at epoch yymmddhhmm
ssssssssC0yymmddhhmm Global clock offset at epoch yymmddhhmm
ssssssssC1yymmddhhmm Global clock rate at epoch yymmddhhmm
ssssssssC2yymmddhhmm Global clock rate drift at epoch yymmddhhmm
ssssssss--ssssssss C baseline dependent clocks
ssssssssNGyymmddhhmm Atmosphere gradient in north direction
ssssssssEGyymmddhhmm Atmosphere gradient in east direction
X WOBBLE 2yymmddhhmm Second time derivative of X pole coordinate at yymmddhhmm
Y WOBBLE 2yymmddhhmm Second time derivative of Y pole coordinate at yymmddhhmm
UT1-TAI 2yymmddhhmm Second time derivative of UT1 angle at epoch yymmddhhmm
Gamma Relativistic PPN parameter gamma
where
"ssssssss" stands for the IVS station name
"qqqqqqqq" stands for the IVS source name
"yyddmmhhss" stands for time epoch like 980729113459 -- July 29, 1998 11 hours
34 minutes 59 seconds.
3.2 Examples of INCLUDE_PARAM and EXCLUDE_PARAM lists
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1. daily_inc.bsc
#
# -- Include parameters which will be put in Sinex listing
#
# The following parameters are to be included in the Sinex listing:
#
# 1) Station coordinates
# 2) pole coordinates
# 3) UT1
# 4) rate of change of pole coordinates
# 5) rate of change of UT1
# 6) daily nutation angles
#
?????????X COMPONENT
?????????Y COMPONENT
?????????Z COMPONENT
?????????X??????-COO
?????????Y??????-COO
?????????Z??????-COO
?????????X??????-POS
?????????Y??????-POS
?????????Z??????-POS
X WOBBLE 0*
X WOBBLE 1*
Y WOBBLE 0*
Y WOBBLE 1*
UT1-TAI 0*
UT1-TAI 1*
LONGITUDE NUTATION
OBLIQUITY NUTATION
2. daily_exc.bsc
#
# -- Exclude parameters which will be put in Sinex listing
#
# Nothing to exclude
#
3. daily_esc_notigo.bsc
#
# -- Exclude parameters which will be put in Sinex listing
#
# All parameters related to station TIGOCONC are excluded
#
# (NB: no common constraint equations with other stations can be
# imposed if computation of the decomposed normal matrix is required )
#
TIGOCONC*
3.3 Treatment of station with discontinuous motion
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
It is an empirical fact that some stations has a quasi-instant motion
due to seismic events and rails changes.
It is an analyst who determines the appropriate model for handing such
stations. In the case if an analyst trusts to results of the measurements
of such a motion by an independent technique, f.e. results of local survey
before and after rails repairing, then position of the station is modeled
by one parameter, and the motion of the station is described by the
set of eccentricity values at the epochs before and after the motion.
If an analyst does not trust to independent measurements, or such
measurements are unavailable, f.e. in the case of seismic motion, then
coordinates of such station are described by a model
X = a1*B0(t0,t1) + a2*B0(t1,t2) + ... + b*(t-tref)
where B0 -- a basis spline of the 0-th order on the range t0, t1
( it is 1 at the range [t0, t1], and 0 otherwise )
tref -- reference epoch;
t0 -- epoch of the first observations;
t1, t2 ... -- epoch of discontinuities.
Parameters a1, a2 ... have the same parameter name STAX, STAY, STAZ
but they are distinguished by sub-index 1,2... in the field SBIN
(former name SOLN). This field is used in sections
SITE/EPOCHS, SITE/APRIORI, SITE/ESTIMATES. If the station did not have
discontinuity in the motion than SBIN always has the value 1.
3.4 Restrictions
~~~~~~~~~~~~~~~~
The current implementation (2002.10.04) cannot write the listing in
Sinex format in several cases:
1) Constraint NO_NET_TRANSLATION is not supported. Use
NO_NET_TRANSLATION_POSITION instead of that.
2) Suppressions
VELOCITIES NO
STATIONS NO
SOURCES NO
PROPER_MOTIONS NO
3) Solve cannot put in the listing site position modeled by linear spline.
4) Currently, Solve can include in Sinex listing global parameters if it
runs in global mode and local parametes if it runs in independent mode.
It cannot include local parameters if it runs in global mode. This
restriction may be lifted in the future.
5) Solve cannot include in the listing in Sinex format second and higher
order UT1 and polar motion time derivatives.
6) Solve cannot include user parameters in the listing in Sinex format,
but can include user constraints.
7) No common constraints between included and not included parameters can
be imposed if computation of decomposed normal matrix is required.
Solve will issue a warning if a constraint equation has non-zero
elements for the parameters from both groups of included and not
included parameters in the case if computation of a decomposed normal
matrix is required, and will issue an error message and stop if the
decomposed normal matrix is to be included in the sinex listing.