Disponible avec une licence Production Mapping.
The Calculate Max Elevation Figures tool computes the maximum elevation figures for a Joint Operations Graphic (JOG) based on the type of the highest vertical obstruction in a quadrangle. Two obstruction types influence the calculation: human-made and natural terrain. The calculation differs if one type is higher than the other.
Human-made vertical obstruction
When a human-made vertical obstruction is higher than the highest natural terrain feature plus an allowance of 46 meters (150 feet) for nonrepresented human-made obstructions in a designated quadrangle, the Calculate Max Elevation Figures tool follows this process:
- Determine the elevation of the top of the obstruction above sea level.
- Add the vertical error of the source material to the above figure.
- Round the resultant figure up to the next higher 100-foot level, if necessary, to achieve a complete value in even hundreds of feet. This final figure is the MEF.
Example
Elevation of obstruction top (above mean sea level) = 2424 Possible vertical error = + 250 Sum Vertical error + obstruction top elevation = 2674 Raise to next higher 100-foot level = 2700 Maximum Elevation Figure (MEF) = 27
Natural terrain feature vertical obstruction
If at least one of the following conditions exist within a designated quadrangle, the following will occur:
- A human-made vertical obstruction is lower than the highest natural terrain feature plus an allowance of 46 meters (150 feet) for nonrepresented human-made obstructions.
- A natural terrain feature is the highest point.
The Calculate Max Elevation Figures tool computes maximum elevation figures following this process:
- Determine the elevation of the feature.
- Add the possible vertical error (one contour interval) of the source to the above figure.
- Add a 46-meter (150-foot) allowance for natural or human-made obstructions that are not portrayed because they are below the maximum height at which the specification requires their portrayal by an obstruction symbol.
- Round the resultant figure up to the next higher 100-foot level, if necessary, to achieve a complete value in even hundreds of feet. This final figure is the MEF.
Example
Highest Terrain Elevation = 3440 Possible vertical error = 250 Allowance = + 200 Sum highest elevation, vertical error, and allowance = 3890 Raise to the next higher 100-foot level = 3900 Maximum Elevation Figure (MEF) = 39
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