Calculate Max Elevation Figures (Production Mapping)

License Level:BasicStandardAdvanced

Summary

Calculates Maximum Elevation Figures (MEF) for each polygon cell or quadrangle in the MEF Feature Layer. MEF values are the elevation of the highest natural or manufactured obstruction plus a vertical error and allowance. This sum is rounded to the next higher hundred-foot level. You use these values 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 Joint Operations Graphic (JOG), Operational Navigation Chart (ONC), Tactical Pilotage Chart (TPC) grid cells, or any other polygon grid features.

Usage

Syntax

CalculateMaxElevationFigures_production (in_mef_feat_layer, in_mef_val_field, in_max_vo_val_field, in_max_dem_val_field, in_mef_allowance, in_terrain_layer, in_point_field, in_terrain_accuracy, in_vo_feat_layer, in_vo_elev_field, in_vo_accuracy)
ParameterExplanationData Type
in_mef_feat_layer

A polygon layer that contains the MEF grid and the three fields that will be updated by the tool.

Feature Layer
in_mef_val_field

The in_mef_feat_layer field in which the tool writes MEF values.

Field
in_max_vo_val_field

The in_mef_feat_layer field in which the tool writes maximum vertical obstruction values from in_vo_feat_layer.

Field
in_max_dem_val_field

The in_mef_feat_layer field in which the tool writes maximum elevation values from in_terrain_layer.

Field
in_mef_allowance

A vertical allowance value added to each calculated MEF value. The value accounts for nonrepresented natural or manufactured features. The default is 200 feet.

Linear unit
in_terrain_layer

A point feature layer or DEM raster layer used to determine the terrain elevation.

Feature Layer;Raster Layer
in_point_field

The field that contains elevation values in in_point_layer. Use this parameter if in_point_layer is a feature layer.

Field
in_terrain_accuracy

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

Linear unit
in_vo_feat_layer

The point layer that contains all the obstructions for the cells for which the MEF values are being calculated; this is generated from a Digital Vertical Obstruction File (DVOF).

Feature Layer
in_vo_elev_field

The field in the vertical obstruction feature layer that contains the elevation values for each obstruction, which is usually the Height Above Mean Sea Level (HEIGHTAMSL).

Field
in_vo_accuracy

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

Linear unit

Code Sample

CalculateMaxElevationFigures example (Python window)

The following Python window script demonstrates how to use the CalculateMaxElevationFigures tool. It uses grid and elevation data from production mapping sample datasets. To use it, change the paths to the sample data and load the script into an empty ArcMap document.

# Name: CalculateLayerSnapshot_Standalone.py
# Description: Creates a layer snapshot on the PipeL sample data.
# Requirements: Production Mapping solution

import arcpy

# check out a foundation license
arcpy.CheckOutExtension("Foundation")

# Use the PipesL feature class from the Production Mapping sample data
PipesL = r'C:\data\Foundation_Data_Tutorials\ProductLibrary\GDB\SoCal_Sample.gdb\PipeL'

# CalculateLayerSnapshot tool requires a feature layer
arcpy.MakeFeatureLayer(PipesL,"PipesLyr")

# exec the tool
arcpy.CalculateLayerSnapshot_production("PipesLyr","snapshotkey")

# check the extension in
arcpy.CheckInExtension("Foundation")

The following ArcGIS label expression can be used to label your maximum elevation figures in the MEF feature layer. To use this label expression:

  1. Execute the Calculate MEF tool on your MEF feature layer.
  2. Right-click the MEF feature layer in the ArcMap table of contents and click Properties.

    The Layer Properties dialog box appears.

  3. Click the Labels tab.
  4. Click Expression.
  5. Load the expression listed below into the Expression window. Make sure you change all [MEF_VALUE] occurrences to the name of your in_mef_val_field.
  6. Click Verify to validate the label expression.
  7. Click OK to close the Label Expression dialog box.
  8. Check on the Label features in this layer check box in the Labels tab of the Layer Properties dialog box.
  9. Click OK to close the Layer Properties dialog box.
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

Environments

Related Topics

Licensing Information

ArcGIS for Desktop Basic: No
ArcGIS for Desktop Standard: Requires Production Mapping
ArcGIS for Desktop Advanced: Requires Production Mapping
12/18/2014