I am a student in an ArcGIS specialization using ArcGIS 10.7.1 for Desktop, and have been struggling to complete part of an assignment.
My assignment is to interpolate ozone data from monitoring stations in California onto a raster, then join it to the map of census tracts dissolved to the approximate county boundaries, and symbolize based on the mean ozone concentration.
- I carried it out by joining the ozone data to the air quality stations and exporting the joined data as a layer, then creating a TIN and subsequent raster. This appeared to be correct based on the screenshot provided of the raster in the assignment description.
- I used the Zonal Statistics as Table tool to get the mean ozone concentration by census tracts and by counties and joined the tables to their respective layers; however, the tables showed some null values for census tracts and counties that should not have been null, and those areas were left blank on the map after applying symbology. I looked up the issue in Stack Exchange and it said to make sure everything was in the same projection (I used NAD_1893_California_Teale_Albers in meters), but it still turned up null values. I attached the counties layer with the selection by attributes MEAN is Null 1, as well as the ozone raster 2, which seems to be correct based on the screenshot provided in the sample.
Do you know what I may have done incorrectly and how to fix the error?
