Calculate Max Elevation Figures (Topographic Production)

Summary

Calculates the maximum elevation figures (MEF) for each polygon cell or quadrangle in a polygon layer. These values are used as labels for the MEF feature layer.

To derive the highest obstruction value, the tool uses terrain data from a digital elevation model (DEM) and vertical obstruction data from a point feature class. You can calculate MEF values for a Joint Operations Graphic (JOG), Operational Navigation Chart (ONC), Tactical Pilotage Chart (TPC) grid cells, NATO STANAG-3591 Edition 6, or any other polygon grid features.

Usage

  • This tool will modify existing features by updating selected fields.

  • You can label the maximum elevation figures in the MEF feature layer. Complete the following steps to apply the label expression:

    1. Run the Calculate Max Elevation Figures tool on the MEF feature layer.
    2. Right-click the MEF feature layer in the Contents pane and click Labeling Properties Labeling Properties.

      The Label Class pane appears.

    3. Ensure that the Label expression tab Label expression is active.
    4. For Language, choose VBScript.
    5. Load the expression below into the Expression window. Change all [MEF_VALUE] occurrences to the name of the mef_field.
      Function FindLabel ( [MEF_VALUE] )
      		Dim l, h, s, f, z, j, len2, lenfin
      		s = [MEF_VALUE]
      		len2 = len(s)
      		If len2 < 4 then
      			l = mid(s, 1, 1)
      			z = "<FNT name='Arial' size='30'>" & "0" & "</FNT>"
      			j = "<SUP><FNT name='Arial' size='30'>" & l & "</FNT></SUP>"
      			Findlabel = z & j
      		ElseIf len2 = 4 then
      			l = mid(s, 1, 1)
      			h = mid(s, 2, 1)
      			z = "<FNT name='Arial' size='30'>" & l & "</FNT>"
      			j = "<SUP><FNT name='Arial' size='30'>" & h & "</FNT></SUP>"
      			Findlabel = Z & j
      		Else
      			l = mid(s, 1, 2)
      			h = mid(s, 3, 1)
      			z = "<FNT name='Arial' size='30'>" & l & "</FNT>"
      			j = "<SUP><FNT name='Arial' size='30'>" & h & "</FNT></SUP>"
      			Findlabel = Z & j
      		End If
      End Function
    6. Click Verify Verify to validate the label expression.
    7. Click Apply.
    8. With the MEF feature layer active, click the Labeling tab.
    9. In the Layer group, click Enable Labeling Enable Labeling.

Parameters

LabelExplanationData Type
Target Max Elevation Figures Features

The input polygon features representing the quadrangle or cell that will be updated with MEF values.

Feature Layer
Input Terrain

The input terrain that will be used to determine elevation values in an MEF feature cell. If a point feature layer is used, elevation values are obtained from the field defined in the Terrain Elevation Field parameter.

Raster Layer; Mosaic Layer; Layer
Vertical Obstruction Features

The layers that will be used to identify the highest human-made structure in a cell. This is a value table defining features, elevation fields, and elevation units.

Value Table
Max Elevation Figures Field

The existing field in the Target Max Elevation Figures Features layer where the maximum elevation figure value will be stored.

Field
Max Vertical Obstruction Field

The field in the Target Max Elevation Figures Features layer where the maximum vertical obstruction value will be stored.

Field
Max Terrain Field

The field in the Target Max Elevation Figures Features layer where the maximum elevation values from the terrain layer will be stored.

Field
Specification

Specifies the specification that will be used to calculate maximum elevation figures.

String
Terrain Elevation Field
(Optional)

A field in the Input Terrain value that represents the elevation values for each feature. If a point feature layer is used for the Input Terrain parameter value, this parameter is required. This parameter is inactive if a raster or mosaic layer is used as input for the Input Terrain parameter.

Field
Vertical Obstruction Allowance
(Optional)

A vertical allowance value that will be added to each calculated MEF value. The value accounts for nonrepresented natural or manufactured features. The default is 150 feet.

Linear Unit
Vertical Obstruction Accuracy
(Optional)

The accuracy of the vertical obstruction feature layer within a specified number of units. The default is 20 meters.

Linear Unit
Terrain Accuracy
(Optional)

The accuracy of the terrain layer within a specified number of units. The default is 20 meters.

Linear Unit

Derived Output

LabelExplanationData Type
Updated Max Elevation Figures Features

The Target Max Elevation Figures Features parameter value with updated MEF values.

Feature Layer

arcpy.topographic.CalculateMEF(target_mef_features, in_terrain, obstruction_features, mef_field, max_vo_field, max_terrain_field, specification, {terrain_elev_field}, {vo_allowance}, {vo_accuracy}, {terrain_accuracy})
NameExplanationData Type
target_mef_features

The input polygon features representing the quadrangle or cell that will be updated with MEF values.

Feature Layer
in_terrain
[in_terrain,...]

The input terrain that will be used to determine elevation values in an MEF feature cell. If a point feature layer is used, elevation values are obtained from the field defined in the terrain_elev_field parameter.

Raster Layer; Mosaic Layer; Layer
obstruction_features
[obstruction_features,...]

The layers that will be used to identify the highest human-made structure in a cell. This is a value table defining features, elevation fields, and elevation units.

Value Table
mef_field

The existing field in the target_mef_features layer where the maximum elevation figure value will be stored.

Field
max_vo_field

The field in the target_mef_features layer where the maximum vertical obstruction value will be stored.

Field
max_terrain_field

The field in the target_mef_features layer where the maximum elevation values from the terrain layer will be stored.

Field
specification

Specifies the specification that will be used to calculate maximum elevation figures.

String
terrain_elev_field
(Optional)

A field in the in_terrain value that represents the elevation values for each feature. If a point feature layer is used for the in_terrain parameter value, this parameter is required. This parameter is unavailable if a raster or mosaic layer is used as input for the in_terrain parameter.

Field
vo_allowance
(Optional)

A vertical allowance value that will be added to each calculated MEF value. The value accounts for nonrepresented natural or manufactured features. The default is 150 feet.

Linear Unit
vo_accuracy
(Optional)

The accuracy of the vertical obstruction feature layer within a specified number of units. The default is 20 meters.

Linear Unit
terrain_accuracy
(Optional)

The accuracy of the terrain layer within a specified number of units. The default is 20 meters.

Linear Unit

Derived Output

NameExplanationData Type
updated_mef_features

The target_mef_features parameter value with updated MEF values.

Feature Layer

Code sample

CalculateMaxElevationFigures example (stand-alone script)

The following code sample demonstrates how to use the CalculateMaxElevationFigures function in Python.

# Name: CalculateMaxElevationFigures_sample.py
# Description: Calculates maximum elevation figures values for JOG data.

# Import System Modules
import arcpy

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

# Setting the environment
arcpy.env.workspace = r'C:\Data\JOG.gdb\BM'
arcpy.env.overwriteOutput = True

# Make Feature Layer for Obstruction Features
arcpy.management.MakeFeatureLayer(r'VerticalObstructionPnt', 'VO_Layer')

# Setting Local Variables
target_mef_features = r'MaximumElevationSrf'
in_terrain = r'C:\Data\w120n34.dt2;C:\Data\w119n34.dt2'
obstruction_features = r'VO_Layer ZVH Meters'
mef_field = 'MEF_VALUE'
max_vo_field = 'MAX_ELEVATION'
max_terrain_field = 'MAX_TERRAIN'
specification = 'JOG_MIL_J_89100'
terrain_elev_field = ''
vo_allowance = '150 Feet'
vo_accuracy = '20 Meters'
terrain_accuracy = '20 Meters'

# Use the Calculate Max Elevation Figures GP tool to calculate maximum elevation figures values for JOG data
arcpy.topographic.CalculateMEF(target_mef_features, in_terrain, obstruction_features, mef_field, max_vo_field, max_terrain_field, specification, terrain_elev_field, vo_allowance, vo_accuracy, terrain_accuracy)

# Check In Extensions
arcpy.CheckInExtension('Foundation')

Environments

Licensing information

  • Basic: No
  • Standard: Requires Production Mapping
  • Advanced: Requires Production Mapping

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