MAGNET Field: Localization

How to perform a multi-point GNSS localization using MAGNET Field. 

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MAGNET Field: Localization

Definition

  • Localization is a process of matching GPS coordinates with the local jobsite coordinates. GPS Lat-Long-Height measurements are made on known x-y-z positions on the jobsite, and the two coordinate systems are matched.

 

Prerequisites

  • Licensed version of MAGNET Field 
  • A new job created
  • Define a non state plane coordinate system
  • Set the coordinate type to ground

 

  • Import or enter a minimum of 4 control points that encompass the whole job site

 

Setup

  • Connect to base receiver (via cable or Bluetooth)
  • Select Setup >> Start Base

 

  • An assumed base is going to be used for this exercise
  • Enter in the assumed base name
  • Enter the base receiver height
  • Select highlighted measurement button to get current GNSS position from base receiver

 

  • Select highlighted 'Stop' button to quit measuring current base position and hold the autonomous GNSS values from the base receiver.
  • Select Start Base
  • Connect to rover receiver (via cable or Bluetooth)
  • Select Setup >> Localization
  • Select 'Settings' button to configure survey collection settings
  • Increase the number of Average measurements to 30 epochs or more. The more averaged measurements taken results in tighter overall residuals
  • Make sure to check Auto Store to automatically store the measurement after the desired number of averaged measurements is met
  • Select green checkmark button in the upper-right to save the settings and exit   

 

Localization Process

  • Select Add to add the first point to the localization
  • Select Use H and/or Use V to hold the point as horizontal and/or vertical control
  • Enter the Known Point or select it from the Map View or List View
  • Name the Measured Point
    • Often a good idea to give the measured point name a prefix of GPS to make associating the known and measured points easier
  • Enter the rover antenna height
  • Select the measure button in bottom-right to record GNSS values for the control point
  • Select green checkmark button in upper-right to save 

 

  • Repeat steps for each additional control point
    • A minimum of 4 points are needed for horizontal and vertical in order to create redundancies and perform statistical analysis, resulting in residual values.
  • Review horizontal and vertical residuals to see if desired standards are met.

 

  • Select Details to view localization parameters, if desired

Quality Control

  • Select Stake >> Points
  • Stakeout a control point to verify the accuracy of the calculated localization