Generate Spot Heights (Topographic Production)

Summary

Creates elevation point features based on contour tops and depressions. Elevation points are created in each top and depression. Point height values are populated based on a digital elevation model.

Usage

• This tool creates multiple points in areas with tops or depressions that have elevations of the same value. For example, if the tool finds two identical elevation values in different locations in the same top, it generates a point at each location.

• A top refers to an elevation completely surrounded by lower elevation contour lines. A depression refers to an elevation completely surrounded by higher elevation contour lines.

• Tops and depressions must be polylines that start and end at the same vertex. The tool will not create spot heights over contour lines that do not start and end at the same vertex.

• If more than one input raster is used, all input rasters must have the same cell size, band count, and pixel type. All input rasters should also use the same elevation units (meters or feet).

Syntax

arcpy.topographic.GenerateSpotHeights(in_contour_features, in_raster, target_spot_features, contour_height_field, spot_height_field, spot_height_subtype, {area_of_interest})

Parameter	Explanation	Data Type
in_contour_features	Contours from which spot heights are computed.	Feature Layer
in_raster [in_raster,...]	Rasters used to derive the highest or lowest elevations in contour tops or depressions.	Raster Layer; Mosaic Layer
target_spot_features	An existing point feature layer or feature class in which spot heights are created.	Feature Layer
contour_height_field	The field in the input contours that contains elevation values. The field type must be numeric.	Field
spot_height_field	The field in the output spot heights to which elevation values are written.	Field
spot_height_subtype	Spot height subtype value assigned to new spot height features that are created.	String
area_of_interest (Optional)	The extent where spot heights will be created. The area of interest (AOI) is the outer extent of all selected polygons in the feature layer. If none are selected, the extent of the raster will be used. This parameter does not accept point layers as valid input.	Feature Layer

Derived Output

Name	Explanation	Data Type
updated_spot_features	Spot height feature class where spot features were created.	Feature Layer

Code sample

GenerateSpotHeights example (stand-alone script)

This Python stand-alone sample code creates elevation point features based on contour tops and depressions.

# Name: GenerateSpotHeights_sample.py
# Description: Creates elevation point features based on contour tops and depressions

# Import System Modules
import arcpy

# Check Out Extensions
arcpy.CheckOutExtension('Defense')

# Setting the environment
arcpy.env.overwriteOutput = True

# Setting Local Variables
input_contours = r'C:\Data\MGCP_TRD_4_4.gdb\MGCP_Delta\ContourL'
input_rasters = r'C:\Data\Monterey.dt2'
target_spot_features = r'C:\Data\MGCP_TRD_4_4.gdb\MGCP_Delta\ElevP'
contour_height_field = 'ZVH'
spot_height_field = 'ZVH'
spot_height_subtype = 'CA040_Spot_Elevation_Point'
area_of_interest_feature_class = r'C:\Data\MapIndex.gdb\MapIndex\TLM50_Index'

# Making a feature layer from the Area of Interest features, and selecting a single feature based on the NRN field
arcpy.management.MakeFeatureLayer(area_of_interest_feature_class, 'AOI_Index')
arcpy.management.SelectLayerByAttribute('AOI_Index', 'NEW_SELECTION', "NRN = 'V795X16573'")

# Calling the Generate Spot Heights to creating spot heights for AOI
arcpy.topographic.GenerateSpotHeights(input_contours, input_rasters, target_spot_features, contour_height_field, spot_height_field, spot_height_subtype, 'AOI_Index')

# Getting all messages, warnings, and errors from the tool run and printing the results back to the user
messages = arcpy.GetMessages(0)
warnings = arcpy.GetMessages(1)
errors = arcpy.GetMessages(2)
arcpy.AddMessage('Tool Messages: {}\nTool Warnings: {}\nTool Errors{}\n'.format(messages, warnings, errors))

# Check In Extensions
arcpy.CheckInExtension('Defense')  # Check in any extensions that were checked out earlier in the script

Environments

This tool does not use any geoprocessing environments.

Licensing information

• Basic: No
• Standard: No
• Advanced: Requires Production Mapping and ArcGIS Spatial Analyst extension