Land Navigation with a Lensatic Compass

2. Course Objectives
At the end of this Module, you will be able to:
Determine how to locate and read a six-digit coordinate on a grid map
Determine how to locate and read an eight-digit coordinate on a grid map
Demonstrate how to determine and measure a magnetic azimuth
Demonstrate how to determine, measure, and plot a grid azimuth
Demonstrate how to measure straight-line distance on a topographic map using the
scales on that map and procedures for calculating distances that exceed those scales
Demonstrate how to measure curved-line distance on a topographic map using the
scales on that map and procedures for calculating distances that exceed those scales
Describe the parts of the lensatic compass
Demonstrate how to hold the compass using the compass to cheek technique
Demonstrate how to hold the compass using the center hold technique

3. Hi,
I am SGT North.
I will be your guide
through this module.
Follow me!

4. Section I
Determining Grid Coordinates
After this section, you will be able to:
Determine how to locate and read a six-digit
coordinate on a grid map
Determine how to locate and read a eight-digit
coordinate on a grid map

5. Practice
Test

6. Southwest Corner
Four Digit Grid Coordinate
When reading a military map there is a rule. The rule is that
you read the map from the left to right then up. To locate the
correct grid square you start at the lower left of the map then
move your finger to the right until you come across the first
two digits. Then you move your finger up until you reach the
second set of digits. Your finger should be on a intersection of
grid lines. That intersection is the south west corner of the 4
digit grid square you are trying to locate. The four digit grid for
the red box is 0593.
To determine the correct
two-letter 100,000-meter-square
identifier, look at
the grid reference box in
the margin of the map.
When reporting across a
100,000-meter line, prefix
the 100,000-meter-square
identification in which the
point lines.
In this example, grid
coordinates located above
the 00 grid line would be
prefixed with EH. Grid
coordinates located below
the 00 grid line would be
prefixed with EG.

7. Southwest Corner
Six Digit Grid Coordinate
Point A
You will place your protractor on the southwest corner of
the grid square that point A is in. Ensuring that the
protractor is aligned vertically and horizontally with the
grid lines, you then slide the protractor to the right until the
vertical scale on the 1/50000 has bisected the point you are
trying to find. In the example EG 058934, the 05 and 93 are
the 4 digit grid square. You will get the 8 off of the
horizontal grid scale on the protractor. You will know it is
8 because when you look at the scale you will see that the
8 is bisected by the 05 grid line. The last number will be
taken by looking at the vertical scale on the protractor.
The point you are trying to find should be bisected by the
vertical scale with the number 4.
Vertical Scale
Horizontal Scale
.

8. Southwest Corner
Point A
Eight Digit Grid Coordinate
You will place your protractor on the southwest corner of
the grid square that point A is in. Ensuring that the
protractor is aligned vertically and horizontally with the
grid lines, you then slide the protractor to the right until the
vertical scale on the 1/50000 has bisected the point you are
trying to find. In the example EG 05799341, the 05 and 93
are the 4 digit grid square. You will get the 79 off of the
horizontal grid scale on the protractor. You will know it is
79 because when you look at the scale you will see that the
79 is bisected by the 05 grid line. The last number will be
taken by looking at the vertical scale on the protractor.
The point you are trying to find should be
bisected by the vertical
scale with the number 41.
When you look at the
scale on the protractor
you will see numbers
from 0 to 1000. There are
9 numbers between each
of those numbers. When
you look at the scale you
have to determine by
estimating where you
think the grid line and
point bisect their
corresponding scale.
.

9. Test
1. Determine a six digit grid coordinate for
the following location. On your map
locate grid square 1582. In that grid
square there is an active open pit mine or
quarry. What is the six digit grid
coordinate to the open pit mine or
quarry?
A. EG 821158
B. EG 158821
C. EH 151828

10. Results
Congratulations! You
are correct! Click
forward to go to the
next question.

11. Results
Sorry you did not
answer correctly! Try
again!

12. Test
2. Determine a eight digit grid
coordinate for the following
location. On your map locate grid
square 1185. In that grid square is a
water tower. What is the eight digit
grid coordinate to the water tower?
A. EG 11508559
B. EH 85591150
C. EG 11598550

13. Results
Congratulations! You
are correct! Click
forward to go to the
next question.

14. Results
Sorry you did not
answer correctly! Try
again!

15. Test
3. Determine a eight digit grid coordinate
for the following location. On your map
locate grid square 1102. In that grid
square there is the Zion Chapel. What is
the eight digit grid coordinate to the Zion
Chapel?
A. EH 02311191
B. EG 11500290
C. EH 11310291

16. Results
Congratulations! You
are correct! Click
forward to go to the
next question.

17. Results
Sorry you did not
answer correctly! Try
again!

18. Tool Box
1. Terrain Features
2. Marginal Information
3. Colors of the Map

19. CONGRATULATIONS!
You Have Completed this
Module