Using the Telemeter as Coordinate Scale
Instrument: Wndsn NATO-MIL Telemeter
Measuring distances on the map with the Telemeter.
The NATO MIL Telemeter has a special scale for maps at a scale of 1:25,000. This coordinate scale is used to measure or transfer rectangular coordinates from or to topographic maps using UTM, MGRS, USNG or other metric coordinate systems.
To determine a position, we first check the scale of the map; then the easting value is determined and then the northing value. The motto for this is: Get to the tree, get up the tree.
Example
We have a map at a scale of 1:25,000. Here we see how to determine the topographic values for east and north.
The easting procedure
- We position the Telemeter horizontally on the map.
- Then we align the 0 of the coordinate scale with the next (left) grid line.
- We then read the value where the scale touches the target (Figure 1).
For an easting of 0.85 km or 850 m.
The northing procedure
- We position the Telemeter vertically on the map.
- Then we align the 0 of the coordinate scale with the next (lower) grid line.
- We then read the value where the scale touches the target (Figure 2).
For a northing value of 0.125 km or 125 m.
The position
The final step is to combine the two values with the base values of our grid:
422,000 E + 850 m
5022,000 N + 125 m
For a position at:
422,850 E 5022,125 N
Other scales
The 1:25,000 scale can also be used for other scales.
For maps in...
- 1:25,000 we use the measured and displayed value as is.
- 1:250,000 we multiply the displayed value by 10.
- 1:50,000 we multiply the measured value by 2.
- 1:100,000 we multiply the measured value by 4.
... as well as multiples or fractions thereof by multiplying or dividing the respective scale by 10.
See also: