ELIM ELIM Ver. 2007.07.18 Description of observation suppression strategy. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Current (starting from f-SOLVE-MAY98) suppression strategy is the following: Each observation has three statuses: 1) "automatic suppression status" -- it is calculated for each observation automatically and takes into account individual characteristics of the observations, such as quality code and global settings such as suppression strategy, usage of ionosphere and so on. 2) "user action for suppression" -- it is set by user individually and may supersede automatic suppression status. 3) "eventual suppression status" -- it is set by taking into account automatic suppression status and user action for suppression. It includes a) USED-status. If .TRUE. then the observation is used in estimation and calculation of statistics. b) RECO-status. If .TRUE. then not USED-observation is allowed to change its status to USED. Otherwise it can never be used in solution in according with used strategy. Automatic suppression status may be: |---------------| |-------------------| |--------------------| | unrecoverable | | conditionally bad | | conditionally good | |_______________| |___________________| |____________________| "Unrecoverable" status means that observation had so severe problems that it may not be used in solutions by no means. "Conditionally bad" status means that this observation considered as bad under conditions taken into account in current suppression scheme and under current global settings. "Conditionally good" status means that characteristics of the observations don't indicate any obstacles against using this observations in solution. User actions for suppression is 1) not to do anything; 2) suppress despite observation is marked as conditionally good; 3) use in solution despite the observation is marked as conditionally bad. User action for suppression is set for group delay and phase delay solutions separately. Implementation. ~~~~~~~~~~~~~~~ Bit filed SUPSTAT keeps status of the observation. Its bits are defined in gbsfc.i: PARAMETER ( BQCX__SPS = 1 ) ! Bad quality code for X-band -- quality code is less that QUALCODE_GOOD_LIM. QUALCODE_GOOD_LIM is set interactively by GAMB, ELIM. It is set in global solution in $SETUP section PARAMETER ( BQCS__SPS = 2 ) ! Bad quality code for S-band. Some databases don't have quality code for S-band. This flag cannot be set up for such databases. PARAMETER ( NOFX__SPS = 3 ) ! No fringes for X-band PARAMETER ( NOFS__SPS = 4 ) ! No fringes for S-band. Some databases don't have quality code for S-band. This flag cannot be set up for such databases. PARAMETER ( CUEL__SPS = 5 ) ! Observation made below cut off limit PARAMETER ( DSBS__SPS = 6 ) ! Observation at deselected baseline PARAMETER ( DSSO__SPS = 7 ) ! Observation of deselected source PARAMETER ( BWVR__SPS = 8 ) ! Bad WVR mask PARAMETER ( BPRN__SPS = 9 ) ! No parangle correction available All GION-like codes are set up only if group ionosphere calibration is applied for observation of this baseline PARAMETER ( GION__SPS = 10 ) ! GION calibration is not available PARAMETER ( GIO1__SPS = 11 ) ! GION calibration is bad: matching observation was downweighted or matching observation didn't have fringes PARAMETER ( GIO2__SPS = 12 ) ! GION calibration is bad: matching observation didn't have fringes PARAMETER ( GIO3__SPS = 13 ) ! GION calibration is bad: matching observation didn't have fringes, since GIONSG=0 PARAMETER ( GIO4__SPS = 14 ) ! GION calibration is bad: matching observation didn't have fringes All PION-like codes are set up only if group ionosphere calibration is applied for observation of this baseline PARAMETER ( PION__SPS = 15 ) ! PION calibration is not available PARAMETER ( PIO1__SPS = 16 ) ! PION calibration is bad: : matching observation was downweighted or matching observation didn't have fringes PARAMETER ( PIO2__SPS = 17 ) ! PION calibration is bad: matching observation didn't have fringes PARAMETER ( PIO3__SPS = 18 ) ! PION calibration is bad: matching observation didn't have fringes, since PIONS=0 PARAMETER ( PIO4__SPS = 19 ) ! PION calibration is bad: matching observation didn't have fringes PARAMETER ( XAMB__SPS = 21 ) ! X-band phase ambiguity not resolved PARAMETER ( SAMB__SPS = 22 ) ! S-band phase ambiguity not resolved PARAMETER ( IUNW__SPS = 23 ) ! IUNW code is not zero PARAMETER ( WPAS__SPS = 24 ) ! Wrong phase delay ambiguity spacings These flags are set in according with values of variables IUNW, IUNWP, LQUAL, LQUALXS, ICORR, GIONSG, PHIONS, IWVBIT1, ISITE, JSITI, ITT, ISTAR, ELEV, KIONO Automatic suppression status is set using these flags and value of variable SUPMET (SUPpression METhod). Suppression method determines which flags to take into account when set status: a) unrecoverable, b) conditionally bad. 5 suppression methods are supported: PRE98 PRE91 COMB1 SNGBA META Flags which are taken into account are determined in $MK5_ROOT/libs/cutil/supuse_set.f as UNRECOVERABLE CONDITIONALLY BAD group delay phase delay group delay phase delay -------------------------------------------------------------- PRE98: NOFX__SPS NOFX__SPS BQCX__SPS BQCX__SPS WPAS__SPS CUEL__SPS CUEL__SPS DSBS__SPS DSBS__SPS DSSO__SPS DSSO__SPS BWVR__SPS BWVR__SPS BPRN__SPS GION__SPS PION__SPS GIO1__SPS PIO1__SPS GIO2__SPS PIO2__SPS GIO3__SPS PIO3__SPS GIO4__SPS PIO4__SPS -------------------------------------------------------------- PRE91: CUEL__SPS CUEL__SPS DSBS__SPS DSBS__SPS DSSO__SPS DSSO__SPS BWVR__SPS BWVR__SPS BPRN__SPS GION__SPS PION__SPS GIO1__SPS PIO1__SPS GIO2__SPS PIO2__SPS GIO3__SPS PIO3__SPS GIO4__SPS PIO4__SPS IUNW__SPS IUNW__SPS -------------------------------------------------------------- COMB1-a: NOFX__SPS NOFX__SPS BQCX__SPS BQCX__SPS NOFS__SPS NOFS__SPS BQCS__SPS BQCS__SPS WPAS__SPS CUEL__SPS CUEL__SPS DSBS__SPS DSBS__SPS DSSO__SPS DSSO__SPS BWVR__SPS BWVR__SPS XAMB__SPS SAMB__SPS -------------------------------------------------------------- COMB1-b: NOFX__SPS NOFX__SPS BQCX__SPS BQCX__SPS NOFS__SPS NOFS__SPS BQCS__SPS BQCS__SPS WPAS__SPS CUEL__SPS CUEL__SPS DSBS__SPS DSBS__SPS DSSO__SPS DSSO__SPS BWVR__SPS BWVR__SPS XAMB__SPS SAMB__SPS PION__SPS GION__SPS PIO2__SPS GIO2__SPS -------------------------------------------------------------- SNGBA: NOFX__SPS NOFX__SPS BQCX__SPS BQCX__SPS WPAS__SPS CUEL__SPS CUEL__SPS DSBS__SPS DSBS__SPS DSSO__SPS DSSO__SPS BPRN__SPS Comments: 1) PRE98 method emulates interactive SOLVE version 98APR. 2) PRE91 suppression method is maintained only to provide backward compatibility with old databases. Long-long time ago SOLVE allowed to restore observations without fringes or with severe problems detected in post-correlation processing what led to setting letter-type of quality codes. PRE91 suppression method allows to use them in solution. PRE91 method emulates batch SOLVE version 98APR. 3) COMB1-a is used for two-bands solution types when ionosphere calibration is calculated on the fly. 4) COMB1-b is used for all other solution types. 5) SNGBA is used for single band solution types when only one band is in use and no ionosphere calibration is applied. When user suppresses conditionally good observation then flag "suppress good observation" is set. When user recovers conditionally good observation this flag is set off. When user recovers conditionally bad observation then flag "restore" bad observation is set. User is not able to recover "unrecoverable observation". Change of the supprssion scheme may change eventual status of the observation.