I am a volunteer groundsman at a small golf club. I had our reticulation GPS located. I have added the GPS locations to a georeferenced image, all good. What I want to do now is add new sprinklers to the map. I do not have GPS data for these new sprinklers.

Is there a way to use distances from the other sprinklers to mark them on the map?

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    What do you mean by "use triangulation to add new sprinklers"? Did you measure the angles and distance from the GPS-located sprinklers to other, existing sprinklers? And you're now trying to map those sprinklers? Please edit your question to clarify. – csk Mar 26 at 15:50
  • That Dropbox link does not provide access to your project file. If you really want to share your project file you can get a direct link to the file by right-clicking on the file and choosing "copy dropbox link". That link will look like this: dropbox.com/sh/[a string of apparently random letters and numbers]. It's probably better just to improve the wording of your question, though. It doesn't sound like we need access to your files to help you. – csk Mar 26 at 21:01
  • Yes, if you have distance and bearing, you can use the Azimuth and Distance Plugin ~ plugins.qgis.org/plugins/qgsAzimuth – nmtoken Mar 27 at 13:49

Assuming you know the distance and direction from a known point to each new sprinkler, QGIS has several tools you can use to map the new sprinklers.

Measurement tool

Attributes toolbar > click on the arrow next to the button with a ruler > Choose Measure Line or Measure Angle

Allows you to measure lines and angles. Easy to use, but can only measure one at a time (lines OR angles).

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Use the Measure Angle tool to find the correct bearing from the known point. (If you turn on snapping (in the snapping toolbar) it will be easy to start your measurements exactly from the known points.) Draw the new sprinkler point along that bearing. Use the Measure Distance tool to measure the correct distance. Move the new sprinkler point to the correct distance. Measure the angle again and adjust the point location. Repeat as necessary.

Advanced Digitizing Tools

Advanced Digitizing toolbar > enable advanced digitizing tools

Create a temporary scratch layer (lines), enable advanced digitizing tools, and start drawing a new line feature. The Advanced Digitizing window will display the angle and length of each line segment as you draw it. (d is distance, a is angle; x and y are the current coordinates under the mouse pointer)

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Draw a line from the known sprinkler point to the location of the new sprinkler, based on the known distance and angle. Draw a point at the end of the line. If you turn on snapping (in the snapping toolbar) it will be easy to place the new point precisely at the end of the line.

Shape Tools plugin

Plugins menu > Manage and Install Plugins > find and install the Shape Tools plugin

Using the Azimuth Distance Digitizer tool, click on the known point. Enter the azimuth (compass bearing) and distance from the known point to the new sprinkler.

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The tool will create a new point at the specified distance and direction from the known point.

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