Changes between Version 4 and Version 5 of binder_ew


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Timestamp:
05/04/12 11:21:42 (9 years ago)
Author:
branden
Comment:

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  • binder_ew

    v4 v5  
    2929'''1. P-wave arrivals''' 
    3030 
    31 Two commands in binder's configuration file tell it where it should get the P-wave arrivals to work on.  The "RingName" command specifies which Earthworm transport ring (a shared memory region) to read from.  Make sure that this is the same ring into which pick_ew is writing its output.  Also, if you're importing picks from another source and want binder to use them, make sure you are placing them in this ring as well.  
    32  
    33 The "GetPicksFrom" command specifies the installation id and module id of the TYPE_PICK2K messages that binder will operate on.  Specific id's or wildcards can be used for either or both of these arguments.  Note: both binder_ew and eqproc should be set to listen to the same pick source(s)! 
     31Two commands in binder's configuration file tell it where it should get the P-wave arrivals to work on.  The "!RingName" command specifies which Earthworm transport ring (a shared memory region) to read from.  Make sure that this is the same ring into which pick_ew is writing its output.  Also, if you're importing picks from another source and want binder to use them, make sure you are placing them in this ring as well.  
     32 
     33The "!GetPicksFrom" command specifies the installation id and module id of the TYPE_PICK2K messages that binder will operate on.  Specific id's or wildcards can be used for either or both of these arguments.  Note: both binder_ew and eqproc should be set to listen to the same pick source(s)! 
    3434 
    3535'''2. Station List''' 
     
    203203Binder hands its locator a starting location and a list of phases. The locator determines the pick weights as above, then calculates the event's average weighted travel-time residual (rms) to use as a reference for testing divergence. 
    204204 
    205 For most earthquakes, the first iteration performed by the locator will be a "Free" solution. It will invert for all four hypocentral parameters: latitude, longitude, depth, and origin time. However, if an event has no nearby picks associated, the locator will perform "Fixed Depth" solution instead. This feature is controlled with the "FixDepth dmin trialz" command (default dmin=50.0, trialz=8.0). If an earthquake has no picks closer than "dmin" km, binder sets its depth to "trialz" km, then inverts for only latitude, longitude, and origin time. This prevents events with no depth resolution from flailing. 
    206  
    207 The result of the locator's inversion is the "step-vector." This is the amount by which the iteration will change all 4 hypocentral components. Binder places limits on the horizontal (xystep) and vertical (zstep) components of the step-vector in any given iteration. Those limits are set with the "MaxStep xystep zstep" command (default xystep=10.0 km, zstep=2.0 km). If either step-length is exceeded in an interation, all 4 dimensions (x, y, z and time) of the step-vector are equally damped, preserving the direction of the vector, such that each dimension is within its configured limit. 
     205For most earthquakes, the first iteration performed by the locator will be a "Free" solution. It will invert for all four hypocentral parameters: latitude, longitude, depth, and origin time. However, if an event has no nearby picks associated, the locator will perform "Fixed Depth" solution instead. This feature is controlled with the "!FixDepth dmin trialz" command (default dmin=50.0, trialz=8.0). If an earthquake has no picks closer than "dmin" km, binder sets its depth to "trialz" km, then inverts for only latitude, longitude, and origin time. This prevents events with no depth resolution from flailing. 
     206 
     207The result of the locator's inversion is the "step-vector." This is the amount by which the iteration will change all 4 hypocentral components. Binder places limits on the horizontal (xystep) and vertical (zstep) components of the step-vector in any given iteration. Those limits are set with the "!MaxStep xystep zstep" command (default xystep=10.0 km, zstep=2.0 km). If either step-length is exceeded in an interation, all 4 dimensions (x, y, z and time) of the step-vector are equally damped, preserving the direction of the vector, such that each dimension is within its configured limit. 
    208208 
    209209Binder also place limits on the valid range for computed hypocentral depth. This range, specified with the "zrange zmin zmax" command (default range is 2.0 - 20.0 km), should span the depth range in which you expect to detect earthquakes. It must also span the entire depth range of the stacking grid ("grdz" command);  otherwise, events may stack outside of the zrange limit and this could cause locator logic errors. If during an iteration, the step-vector causes the depth to fall outside of the zmin-zmax range, that step vector is abandoned. The locator then "restarts" the iteration; beginning with the previous starting hypocenter, the locator performs a fixed-depth solution.  This feature is useful in controlling locations from network "glitches" where all picks are coincident and the apparent 
    210210high phase velocity would try to locate the quake at the center of the Earth.  
    211211 
    212 At the end of each iteration, binder recalculates the event's average weighted residual (rms) and performs a test for divergence.  If the new rms is greater than the previous rms*"constant" (set with "MaxDeltaRms" command, default = 1.01), then the solution is diverging. If the location is converging, the locator goes on to the next iteration. If a location is diverging, binder removes half of the step-vector in all 4 dimensions (x, y, z and time), backing the location up toward the starting location from that iteration, and then checks the rms again. If the solution now converges, the locator goes to the next iteration. If the solution is 
     212At the end of each iteration, binder recalculates the event's average weighted residual (rms) and performs a test for divergence.  If the new rms is greater than the previous rms*"constant" (set with "!MaxDeltaRms" command, default = 1.01), then the solution is diverging. If the location is converging, the locator goes on to the next iteration. If a location is diverging, binder removes half of the step-vector in all 4 dimensions (x, y, z and time), backing the location up toward the starting location from that iteration, and then checks the rms again. If the solution now converges, the locator goes to the next iteration. If the solution is 
    213213still diverging, it backs the location up farther. Up to 3 backwards steps will be made (resulting in a step-vector of 1/8 the original size) if the solution continues to diverge. 
    214214 
    215 Binder's locator will perform a maximum number of iterations every time that it's called. The maximum iteration count can be set with the "MaxIter" command (default = 4). However, the locator may perform fewer than MaxIter iterations if the change in the location (in X-Y-Z km) in any given iteration is less than a minimum step-length (set with the "MinXYZstep" command; default = 0.1 km). 
     215Binder's locator will perform a maximum number of iterations every time that it's called. The maximum iteration count can be set with the "!MaxIter" command (default = 4). However, the locator may perform fewer than !MaxIter iterations if the change in the location (in X-Y-Z km) in any given iteration is less than a minimum step-length (set with the "MinXYZstep" command; default = 0.1 km). 
    216216 
    217217 
     
    283283 
    2842844. Are the stacking grid boundaries set properly? 
    285    Lats & lons are in decimal degree with positive = N, E. 
     285Lats & lons are in decimal degree with positive = N, E. 
    286286 
    287287