arcgis desktop - Measuring area of raster classes?

Are there any tools or methods in ArcMap that can measure the area of each level of the kernel density output?

Note this is just a kernel density plot (not a shape file or polygon). Kernel Density Analysis (dark green (10%) to red (90%) (1)

I have tried a few things but i need it to be accurate.

Answer

I would use the following workflow to calculate the area within the classes:

1. Reclassify (Spatial Analyst) the kernel density output to whichever classes you are using. By default ArcGIS creates a continuous raster surface for the kernel density output, but reclassifies the legend (which is temporary). Using the reclassify tool will make this permanent.


2. Open the reclassified kernel density attribute table and observe the "COUNT" field (Figure 1). This is the count of all the pixels in each class. For example, Class 1 (Value = 1) has a count of 620,063 pixels. Since my coordinate system is UTM, the units are in meters and the pixels are at 1m spatial resolution. Therefore, Class 1 is 620,063 m^2.


3. To convert the count to other units such as hectares, add a new field in the attribute table.


4. Calculate field (Figure 2)


5. Logic check the results by highlighting a class (Figure 3)

---

Figure 1

Figure 2

Figure 3