Changes between Initial Version and Version 1 of pkfilter.designspecs.txt

03/25/12 13:57:18 (9 years ago)



  • pkfilter.designspecs.txt

    v1 v1  
     2Design Requirements for a Pick Filter 
     41. The purpose of the pick filter is to reduce the number of "duplicate" picks 
     5   from a given "station". For the pick filter, all components which have 
     6   matching station code and network code are considered to be the from the 
     7   same "station". The rules for what are considered "duplicate" picks are 
     8   given below. 
     102. For each "station", the pick filter will maintain a history list of picks 
     11   that have been allowed through the filter. The size of these lists will be 
     12   limited by a configurable number (count) of picks. 
     14   LDD: Added the "PickHistory" command to specify the number (count) of 
     15   picks that will be maintained in the list for each "station".   
     16   Only picks which pass the filter rules are added to the list. Once  
     17   the list is full, old picks are removed in a simple first-in, first  
     18   overwritten manner. 
     203. The pick filter can optionally be configured to pass picks from only 
     21   certain component codes. 
     23   LDD: Added "AllowComponent" command. If no "AllowComponent" command is  
     24   used, ALL components will be allowed to pass. If one or more "AllowComponent" 
     25   commands are used, the pick filter will only pass picks from the listed 
     26   components. 
     284. The following rules may be used to determine if a pick is allowed through 
     29   the filter. Any pick that fails these rules is considered a "duplicate" and 
     30   is rejected by the filter. 
     32   A new pick is considered to "match" a pick in the history list if the two 
     33   pick times are within "pick tolerance" of each other. That is, a new pick 
     34   within "pick tolerance" before or after a listed pick is considered to 
     35   match the listed pick. 
     37   LDD: Set with original "PickTolerance" command. 
     39   a. A pick that is more than "pick tolerance" newer than the most recent 
     40      listed pick is always passed by the filter. 
     42   b. "Allow higher quality matches": A pick that "matches" a listed pick and 
     43      has a higher quality than that matching pick is optionally passed by the 
     44      filter. 
     46      LDD: Set with original "DuplicateOnQuality" and "QualDiffAllowed" commands. 
     48   c. "Allow older": A pick that is more than "pick tolerance" older than the 
     49      older listed pick is optionally passed by the filter. 
     51      LDD: Added two new commands to control this feature. 
     52      "OlderPickAllowed" has 3 possible values: 
     53        0=pass no non-duplicate picks older than the youngest passed 
     54          pick for this station. 
     55        1=pass older picks, but set a limit on how old they can be. 
     56        2=pass all non-duplicate picks older than the youngest pick 
     57          for this station.  
     58      "OlderPickLimit" is used only if OlderPickAllowed=1. If a  
     59       non-duplicate pick is older than they youngest-passed pick by  
     60       more than OlderPickLimit seconds, the pick will be rejected.   
     62       I included the "OlderPickLimit" option because I noticed in CI data,  
     63       that some channels at a station can arrive many minutes later than  
     64       another channel at the same station.  I assume that this is due to 
     65       recovery on a bad telemetry link.  If we want to keep the pick history 
     66       relatively short and still let older picks thru, we need to set a time  
     67       limit on the oldest picks we'll accept. Otherwise we could still end up  
     68       with lots of duplicates in the system.  And if new picks exist, the older 
     69       ones won't really help binder at all. 
     715. Coda messages can also be filtered by the pick filter. The options should 
     72   include "allow all", "allow none", and "allow matching". Codas are 
     73   considered to match picks for a given "station" if the pick and coda have 
     74   the same serial number, installation and module IDs. The Earthworm picker 
     75   assigns serial numbers to picks and codas; the installation and module IDs 
     76   are part of the "logo" assigned to all Earthworm messages. 
     78   LDD: Added "CodaFilter" command for this feature.  
     79        It has 3 possible values: 
     80        0=allow no codas 
     81        1=allow matching codas 
     82        2=allow all codas