[GIS] Correlation between raster values and vector point values

arcgis-10.3arcgis-desktopcorrelationinterpolationraster

I will be using aerial photography/Object Based Image Analysis to separate plants in a field from their background, creating a polygon for each plant.

I will then convert these polygons to point on centroid and retain each polygon's area attribute, yielding DATASET 1.

I have a raster map of soil moisture of this field, DATASET 2, upon which I will overlay and georeference DATASET 1.

I will be normalizing the data so all raster pixel values in DATASET 2 and point values in DATASET 1 fall between 0 and 1.

I want to analyze the spatial correlation between the values of the points in DATASET 1 (plant area) collocated with values in DATASET 2 (soil moisture).

Can anyone suggest a technique to execute this? I have done a lot of research yet am finding it hard to find precedent to wrap my head around the problem.

I will be using ArcGIS 10.3 for Desktop to process the datasets.

Best Answer

You should use "Extract Values to Points (Spatial Analyst)", to join pixel values to your point feature class. Make sure to check "Interpolate values at the point locations" so any missing value gets interpolated based on its surrounding pixels.

you will end up with a point feature class containing both plant area and soil moisture as attributes. To find the correlation you have many options:

  1. Export the table to a xls and use excel (Simplest)
  2. Use ArcGIS Graph to draw a linear regression line between the two variables
  3. Use python (numpy) to do get the correlation matrix
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