How to separate plots and extract plot data using QGIS (Drones in agriculture series, 5/7)

In this video we cover how to separate plots and extract data from drone imagery using shapefiles in QGIS.
1:10 Measuring plot size
2:24 Creating the grid
6:30 Editing the grid (color, position, rotation)
18:23 Accessing the attribute table
21:12 Zonal Statistics: Adding plot data to attribute table
26:55 Moving attribute data to other programs

If you found these methods useful, please consider citing our recent paper in the journal Remote Sensing:

Parker, T. A., Palkovic, A., & Gepts, P. (2020). Determining the Genetic Control of Common Bean Early-Growth Rate Using Unmanned Aerial Vehicles. Remote Sensing, 12(11), 1748.

[bbourland]

Amazing video! Incredibly helpful and well-explained.

[juanignaciocarrano]

I developed a software many years ago to do exactly this. GIS software is no longer an option when you get to the 1000s of plots. A field like show here would take just a couple of minutes with the custom software. For more complicated grids you could split it (and rejoin) at selected rows or columns.
A key to a good fit is the transform/deformation type: I found bilinear is superior to projective.

[pepe-oryk]

Hi Travis,
Your video is useful! I am new to qgis. Besides is there a way to use grid to clip image to small plot? Thanks

[sewie]

These videos have been a massive help with my work! Do you know if there's a simple way to assign a row and column number to the attribute table for each plot? All of our plots use a grid reference starting at y1:x1 in the bottom left corner. Solving this issue will make sorting the data lot easier.

[kasunrathnayaka]

This video series are excellent, it was really help me to get proper idea about my final year research.
Thank you very much
Can i contact you for get more instructions about drone mapping and NDVI time series for paddy varieties

[relaxationmusicinn]

Hi Travis! Thanks for the great tutorial for QGIS, I am a beginner of this, so I have no idea how do you get the threshold layer, 0 value layer, 1 value layer, can you tell me more about it? Thanks again!!

[edujacque]

Hi Travis!
Thanks for sharing your knowledge in those items. I am also experimenting in those matters. After getting the Threshold to separate plant from soil, I have converted the raster file to a vector file using the Polygonize tool (under Raster Menu) to isolate each plant and make a calculation of how many plants I have in the plot. Did you tryed with this tool too or do you use other command/tool/function to summarize the amount of plant on a plot? Thanks a lot in advance.

[capsulaproducciones]

Hi travis, nice tutorial!! just a question, my ebee sq comes with just 4 multispectral bands, I dont have the blue one, is there any way to get it by separating RGB image?

[francisagreement]

Travis, can this process work with LiDAR Data?

[luisvillarroel]

Hello Travis , we are trying to count agave plants, but we are usign a RGB camera dron, (no multiepectral), for doing the orthomosic, so all I am getting is a tiff orthomosic where all bands are on one file orthomosic ? the tiif file gives me 4 bands but I cant really clasify them on E, G, B as you are doing for procesing, can you give me any advice ?