GPS900 – creating a local coordinate system (sometimes known as an “on-site calibration”) using the “GPS Resection” application program.
GPS Resection step-by-step
1. Start the Program
• Type in a Name for the resection (grid), select a Job and continue (CONT (F1)).
2. Measuring the local points
• Select Point ID of the known local point and occupy it. Hold the GPS real-time rover steady.
• Start measuring the point (OCUPY (F1)).
• End measuring the point (STOP (F1)).
• Store the measured point (STORE (F1)).
3. Matching the local points to WGS84 coordinates for position and/or height
• Select the type of match between the measured WGS84 and the known local point (MATCH (F5)).
• Survey another WGS84 point (ADD (F2)).
• Confirm the selections and compute the transformation (CALC (F1)).
4. Checking the calculated residuals
• Check the calculated residuals.
• Press MORE (F5) to display information about height residuals.
• If the residuals are unacceptable, return to Step 2 (ESC )where you can edit, delete or temporarily points from the list and recalculate the transformation.
• Save the coordinate system and attach it to the active job (STORE (F1)).
2. Measuring the local points
• Select Point ID of the known local point and occupy it. Hold the GPS real-time rover steady.
• Start measuring the point (OCUPY (F1)).
• End measuring the point (STOP (F1)).
• Store the measured point (STORE (F1)).
3. Matching the local points to WGS84 coordinates for position and/or height
• Select the type of match between the measured WGS84 and the known local point (MATCH (F5)).
• Survey another WGS84 point (ADD (F2)).
• Confirm the selections and compute the transformation (CALC (F1)).
4. Checking the calculated residuals
• Check the calculated residuals.
• Press MORE (F5) to display information about height residuals.
• If the residuals are unacceptable, return to Step 2 (ESC )where you can edit, delete or temporarily points from the list and recalculate the transformation.
• Save the coordinate system and attach it to the active job (STORE (F1)).