Lloyd Bosworth : archaeologist | human | beard

Posts in the qgis x y coordinates category

This QGIS tutorial is part of a series detailing my journey moving from ArcGIS to QGIS and how I’ve relearned familiar ArcGIS workflows. I’ve been using ArcGIS for many years and the move to QGIS has at times presented quite a steep learning curve. Some of what I have learned has come from trial and error, but the greater majority has come from searching forums and other blogs and I try to credit these sources as I go along. Writing these articles is both a personal aide-memoire and a way to cement the new skills I am learning, but if they are helpful to others, then all the better.

QGIS tutorial for archaeologists wanting to create survey grids and export as points to use with a GPS or Total Station.

Creating and Orienting Vector Grids in QGIS 2.18

In this QGIS tutorial I will use a real-life geophysical survey to detail how I use QGIS to create polygon grids, how I orientate them to fit the area of interest and how I export the grid as points to use with a GPS or Total Station system.

In archaeology, laying out a grid before a survey or excavation is an essential part of keeping a fieldwork project organised. Grids can be aligned to real-world coordinates, such the British National Grid here in the UK, or can be on an arbitrary alignment, called a site grid, chosen to best fit the terrain or landscape. A site grid will commonly use a field boundary, verge, fence line or other linear feature as a baseline from which to measure out the grid.

Gridding out, as it’s called, can be done quickly in the field by one or two people using surveyor’s tapes. I’m fortunate to have access to a GPS Rover which can achieve the same result as using hand tapes, but much more quickly and with millimetre accuracy. The other benefit of using a GPS is that the grid can be created in QGIS in the office and transferred precisely onto the field.

QGIS Tutorial Contents

  1. Creating the grid
  2. Orienting the grid
  3. Converting polygons to points
  4. Exporting point layers
  5. How does this workflow compare with ArcGIS?