Hints for Easing Error Correction Woes

All errors should be corrected as soon as possible as they tend to multiply when left unattended. The trapper is the best source of information in most cases and should be contacted as soon as possible after a problem has been detected. If the trapper is unavailable, then the trapper’s written logs or maps on which he/she has plotted trap locations is the next best choice. The ArcIMS Map Server (available on the STS web site) and ArcView are also extremely helpful tools. It is much easier to ‘see’ a trap location in a graphical display such as the STS Map Server than it is in the error reports. The majority of errors are the result of trappers submitting records with incorrect quad and/or site numbers. Keep this in mind as you are working on error corrections.

Problems With Trap Placement Records

When you see the following: Try this:

Duplicate Site in Quad

(records have different UTM coordinates)

  • Look at the UTM coordinates of both GPS records to determine if one record was coded with an incorrect quad code and/or site number. The UTM coordinates should be within several hundred meters of the target UTM coordinates for the quad code and site number in the GPS record (the distance varies depending on the trapping grid). The UTM coordinates for both records are included on the error reports.
  • If the UTM coordinates of either of the two records are close to a different site, check to see if a record has been submitted for that site. If there is no record for that site, the quad code and/or site number of the record in error can be changed. Confirm this with the trapper before you make the correction.
  • If the first record was entered into the database with an incorrect quad code and/or site number, you will need to contact the database administrator at MSU or VT and ask them to make the correction. If the second record was entered with an incorrect quad code and/or site number you can change the record yourself.

Duplicate Site in Quad

(records have similar UTM coordinates)

  • If the UTM coordinates of both GPS records are within the target circle for the same site, you will need to find out from the trapper whether any of the following are true:
  1. He/she accidentally entered two trap placement records for the same site;
  2. One record was submitted with an incorrect quad code and/or site number;
  3. The first record reported an omitted site, and the trapper submitted a second record when he/she was later able to place a trap;
  4. The trapper submitted a second trap placement record when he/she moved the trap from its original location;
  5. The trapper placed two traps within the target circle of one predetermined site;
  6. The first record was a trap placement record, and the second record should have been formatted as a trap inspection record.
  • Based on the trapper’s response, determine whether a record needs to be corrected or deleted.
Site is listed on the ‘Outside Target’ Report
  • The sites that are at least 1,000 meters beyond the target circle are the most important to check. However, all sites on the list should be reviewed. In some cases you will find that the record is on the list because the quad or site number was entered incorrectly and in others the trap was placed beyond the target area.
  • For a site that is at least 1,000 meters beyond the target circle, look at the UTM coordinates of the record (Record A) and see if the location falls within the target circle for another site. (The Map Server and ArcView are great tools for this task.) If it does, check to see if a record has already been submitted for the other site. If a record exists (Record B), check the UTM coordinates of that record to see if the location is within the proper target circle. (Site numbers are sometimes switched for two records.) If the site numbers have been switched, the UTM coordinates of Record B will fall within the target circle of Record A, and the UTM coordinates of Record A will fall within the target circle of Record B. Confirm the trap locations with the trapper and ask the database administrator to change the site numbers of the two records.
  • If the UTM coordinates of Record A fall within the target circle of another site and no record exists for that site, confirm with the trapper that the quad and/or site number should be changed. Then ask the database administrator to make the appropriate correction. (If the site number of Record A is not corrected, you will eventually see a ‘duplicate site’ error when the ‘real’ record is submitted for the target circle of Record A.)
  • If the UTM coordinates do not fall within the target circle of another site, it is possible that the trap was placed outside of the target circle. It is also possible that the trapper accidentally created a record en route to a trap site. Confirm the UTM coordinates with the trapper and based on the trapper’s feedback decide whether the trap should remain at that location.

Problems With Trap Inspection Records

When you see the following: Try this:

Duplicate Final Visit

  • It is assumed by the database that a trap is removed when an inspection record is coded as a ‘final’ visit. An error is generated if more than one ‘final’ inspection is submitted for a single trap. NOTE: Supervisors may submit ‘final’ QC inspections in addition to the trapper’s routine final inspection if they are performing follow-up checks to confirm trap removals. The supervisors’ inspection records must include the appropriate QC codes of ‘P’ or ‘F’.
  • This error often occurs because a trapper mislabels an inspection record with an incorrect quad and/or site number. Check the UTM coordinates of both inspection records. If the UTM coordinates of one of the records are close to the coordinates of another trap, then it is possible that the trapper entered an incorrect quad code and/or site number. Confirm with the trapper that this is what happened. If no ‘final’ inspection exists for the other site, correct the quad code and/or site number of the appropriate inspection record. The database administrator will need to make the correction if the first inspection record was submitted incorrectly.
  • If the UTM coordinates of both records are correct for the site being reported, you might check the inspection date. If the date in one of the inspection records occurs earlier in the trapping season, it is possible that a ‘midseason’ inspection was coded as a ‘final’ inspection. Confirm this with the trapper and change the appropriate record to a ‘midseason’ inspection. (All ‘midseason’ inspections must take place before the ‘final’ inspection.) The database administrator will need to make the correction if the first record that was submitted is incorrect.
  • If all of the data in both records appear to be identical, then it is possible that the trapper submitted two records for the same trap. Confirm this with the trapper and delete the second record.

Duplicate Inspection

  • A trapper should inspect a trap no more than one time per day. An error is generated if more than one inspection record is submitted with the same values in the following fields: quad, site, inspection date, and QC check. A supervisor may submit a QC inspection with the same date as a trapper’s routine inspection, but it must be coded with a ‘P’ or ‘F’.
  • This error occurs frequently when a trapper submits an inspection record with an incorrect quad code and/or site number. Check the UTM coordinates of both inspection records. (Another great opportunity to use the Map Server or ArcView.) If the UTM coordinates of one of the records are close to the coordinates of another trap, then it is possible that the trapper entered an incorrect quad code and/or site number. Confirm with the trapper that this is what happened. If no inspection exists for the other site, correct the quad code and/or site number of the appropriate inspection record. The database administrator will need to make the correction if the first inspection record was submitted incorrectly.
  • If all of the data in both records appear to be identical, then it is possible that the trapper submitted two records for the same trap. Confirm this with the trapper and delete the second record.
No Trap Placement Record Match
  • A trap placement record must be submitted (and must be error-free) before an inspection record can be accepted by the database. There are several situations in which this error occurs:
  1. The inspection record was submitted with an incorrect quad code and/or site number.
  2. The trap placement record was submitted with one or more errors that have not yet been corrected.
  3. Very rarely, a site number may have been changed after a trap was placed. The trapper included the old site number in the inspection record.
  • Check the UTM coordinates of the inspection record to determine whether there is a placement record with similar coordinates. (I would again suggest the map server or ArcView.)
Inspection at Omitted Site
  • There should be no inspections at omitted sites since no traps are placed at these locations. This error occurs most frequently when a trapper mislabels an inspection record with an incorrect quad code and/or site number.
  • Check the UTM coordinates of the inspection record to determine if the quad code and/or site number were entered incorrectly. Make the appropriate corrections.
  • If the quad and site are correct, confirm with the trapper whether the site was omitted.
  • If an omitted site record was submitted even though a trap was placed, contact the database administrator at MSU or VT. The DBA will need to know the type of trap and the date it was placed in order to make the correction.
Site is listed on ‘Inspect_Dist’ Report
  • The inspections that are at least 1,000 meters from the trap placement locations are the most important to check. However, all sites on the list should be reviewed. In some cases you will find that the inspection record is on the list because the quad code or site number was entered incorrectly.
  • It is also possible that the trap PLACEMENT record was labeled with an incorrect quad code or site number. The inspection record would be correct in this case, but the placement record would need to be corrected.
  • For a site that has an inspection at least 1,000 meters from the trap placement record, check the UTM coordinates of the record (Record A) and see if the location falls within the target circle for another site (using the Map Server or ArcView). If it does, check to see if an inspection record has already been submitted for the other site. If a record exists (Record B), check the UTM coordinates of that inspection record to see if the location is within the proper target circle. (The site numbers may have been switched.) If so, the UTM coordinates of Record B will fall within the target circle of Record A, and the UTM coordinates of Record A will fall within the target circle of Record B. Confirm the trap locations with the trapper and ask the database administrator to make the appropriate corrections.
  • If there are a large number of sites on the list with a distance between 200 and 300 meters, it is possible that there was a problem with the datum setting in the MapSite software. Check the computer that was used to download the GPS records to be sure the datum was set to NAD27 when the records were downloaded. Contact the database administrator if the datum was set to something other than NAD27.
   
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