Calculating Area solar radiation gives ERROR 000732: output raster considered as Input?

Question

I am trying to calculate Area solar radiation for rasters in a list.

It seems that the tool allows to create unique rasters for direct, diffuse and direct radiation duration, and calculates outGlobalRadiation as the final output.

But, when I define the names for the direct, diffuse and direct radiation duration rasters, I got back an error RuntimeError: ERROR 000732: Input Raster: Dataset dir_1 does not exist or is not supported meaning, that my optional output file is actually considered as Input Raster, and does not exist.

Do you understand this error? Or is there any logical error in my script?

import arcpy, os
from arcpy.sa import *

arcpy.CheckOutExtension("spatial")

# Get path
inWD = "C:/Users/2019_bioESS_coord"

# Set working environment
arcpy.env.workspace = os.path.join(inWD, "output/bufRastTwins.gdb")
arcpy.env.overwriteOutput = True

# List all rasters
rasters= arcpy.ListRasters("r_*")


# Calculate solar radiation with defined optional outputs
for raster in rasters:

    # Define names for output optional rasters
    outNameDirect = "dir_" + raster.replace("r_", "")
    outNameDiff = "diff_" + raster.replace("r_", "")
    outNameDirDur = "dirDur_" + raster.replace("r_", "")

    # Define parameters for solar radiation
    in_surface_raster = raster
    latitude = ""
    skySize = 200
    timeConfig = TimeMultipleDays(2018, 100, 150)
    dayInterval = 10    # default 14
    hourInterval = 12   # default 0.5
    each_interval = "NOINTERVAL"  # "INTERVAL"
    zFactor = ""
    calcDirections = 32
    zenithDivisions = 8
    azimuthDivisions = 8
    diffuseProp = 0.3
    transmittivity = 0.5

    # Set names for optional output rasters, seems not working???
    outDirectRad = arcpy.Raster(outNameDirect)  
    outDiffuseRad = arcpy.Raster(outNameDiff)
    outDirectDur =  arcpy.Raster(outNameDirDur) 


    # Execute AreaSolarRadiation
    outGlobalRad = arcpy.sa.AreaSolarRadiation(in_surface_raster, latitude, skySize, timeConfig,
                                               dayInterval, hourInterval, each_interval, zFactor, "FROM_DEM" ,
                                               calcDirections, zenithDivisions, azimuthDivisions, "UNIFORM_SKY",
                                               diffuseProp, transmittivity,
                                               outDirectRad, outDiffuseRad, outDirectDur)

    print("area radiation saving")
    # Save the output 
    outGlobalRad.save(raster.replace("r_", "globRad_"))

Answer 1

I think to make your script work you should:

1. remove all the arcpy.Raster() calls

# Set names for optional output rasters, seems not working???
outDirectRad = arcpy.Raster(outNameDirect)  
outDiffuseRad = arcpy.Raster(outNameDiff)
outDirectDur =  arcpy.Raster(outNameDirDur)

2. change the call to arcpy.sa.AreaSolarRadiation like this:

# Execute AreaSolarRadiation
outGlobalRad = arcpy.sa.AreaSolarRadiation(in_surface_raster, latitude, skySize, timeConfig,
                                           dayInterval, hourInterval, each_interval, zFactor, "FROM_DEM" ,
                                           calcDirections, zenithDivisions, azimuthDivisions, "UNIFORM_SKY",
                                           diffuseProp, transmittivity,
                                           arcpy.Raster(outNameDirect), arcpy.Raster(outNameDiff), arcpy.Raster(outNameDirDur))

If it works, the reason is that arcpy.Raster documentation reads that:

A raster object can be created in two ways, by supplying the path to an existing raster on disk, or it can be the result of any Map Algebra statement that results in a raster output.

So, either you give an existent raster, or (as in your case) the input is generated by a function (internally I guess arcpy.sa.AreaSolarRadiation is doing this for you).