I have a shapefile with >300 points that correspond to the points where vegetation survey plots were carried out 10m from the road on both sides. Plots have the dimensions 20mx50m. The attributes table has a row for each plot and a column that indicates whether the plot was made on the left or right side of the road. I need to place a polygon 20m measured perpendicular to the road of said dimensions, on either side of the GPS point (as shown in the image below)
I have a survey trail shapefile that I extracted indices from that has an angle column (which I think should be useful) which I hope to use to determine the perpendicular angle for the polygon placement. The geometries have been made to line up perfectly (point shapefile and line shapefile).
I have searched a variety of things on StackExchange and Google, but this is quite a unique and complex geometry issue that I think has not been tackled before. I am aware that I can create a polygon for each point and then manually move it but I was hoping not to since in total there will be more than 600 polygons. I am on QGIS 3.4.4 Madeira, Windows 10.
Each point (representing two vegetation plots, one either side) has a timestamp, so it is clear which direction is forward as it gets later. From this, we should be able to determine which side was right and which left to the surveyor. Polygons are to be parallel to the survey trail (line shapefile).