Instructional Materials Service Texas A&M University - 8987E - Compass & Pacing Instructional Materials Service Texas A&M University - 8987E -

Compass & Pacing Baseplate Compass Engineer’s Lensatic Compass Pacing Compass Use

Baseplate Compass There are several grades and types of compasses. A good baseplate compass will have a: Rotating, fluid-filled housing Baseplate Compass needle North alignment needle Direction-of-travel arrow

Baseplate Compass Scale Direction-of-travel arrow Magnifier North alignment Rotating housing Compass needle Orientation lines Compass housing

Baseplate Compass Baseplate compasses may include: A scale A magnifier Templates Lanyard (a wrist, or neck travel cord) Scale Direction-of-travel arrow Magnifier Slot for lanyard

Baseplate Compass The fluid-filled housing slows the motion of the needle so the operator does not need to hold the compass motionless during use. Housing

Baseplate Compass The compass housing includes degree marks, 0° to 360°. The reading for North is both 0° and 360°. Housing

Baseplate Compass The red end of the compass needle always points to Magnetic North. North alignment Compass needle

Engineer‘s Lensatic Compass Compass includes: A fluid-filled housing A Magnetic North arrow Directional marks A magnifying lens A line-of-sight directional viewfinder

Pacing

Pacing Two methods of pacing: Pace equals two steps Pace equals steps traveled in a 100-foot distance

Method 1: Pace Equals Two Steps

Pace Equals Two Steps Determining an accurate pace: Measure a 100-foot distance between two markers, Point A and Point B. The area between the markers should be flat and free of obstacles.

Pace Equals Two Steps Travel from Point A to Point B, counting off each step. Repeat several times recording step count each time.

Pace Equals Two Steps Divided total number of steps recorded (120) by number of attempts completed (3) (120) steps ÷ (3) attempts = 40 steps Average equals (40) steps.

Pace Equals Two Steps Divide (100) distance by (40) step average 100 ÷ 40 = (2.5) step length Multiply (2.5) step length by (2). 2.5 x 2 = 5 Pace = 5 feet

Method 2: Steps Traveled in 100 Feet

Steps Traveled in 100 Feet Once an average pace is established, it is possible to determine how many steps it will take to travel a given distance. In this example, 40 steps = 1 pace

Steps Traveled in 100 Feet Distance from point A to point B = (160) steps Pace = (40) steps Divide (160) distance from A to B by (40) steps 160 ÷ 40 = 4 Multiply 4 by (100) distance used to find pace 4 x 100 = 400 Distance to target is 400 feet

Steps Traveled in 100 Feet Calculate the number steps to travel a distance of 185 feet. Divide (185) distance by 100 185 ÷ 100 = 1.85 Remember: 40 steps = 1 pace Multiply 40 by 1.85 1.85 x 40 = 74 It will take 74 steps to travel 185 feet.

Pacing (Obstacles) It is necessary to determine pace on uneven terrain, through ditches, grasses, trees, brush of various heights, and other obstacles.

Pacing Beginners should: Use a measuring tape to accurately measure a 100-foot distance. Practice on clean, level ground, using a natural walking gait. Maintain a constant, reliable pace, regardless of the obstacles.

Compass Use

Compass Use The Earth’s North and South poles act like a huge magnet. One pole is positive and one pole is negative. Because magnetic and true North are not the same, corrections are made in surveying to compensate for this difference. The difference is referred to as magnetic declination.

Compass Use The compass needle, which floats in the fluid-filled chamber, is magnetized. Regardless of the compass position, the red needle is drawn to the Magnetic North Pole.

Compass Use The circular rotating housing enclosing the needle is marked in degrees in increments from 0° to 360°. Degrees are also referred to as the azimuth or bearing. Housing

Compass Use Directional letters N, S, E, and W, are identified on the housing. North South East West

Compass Use Example: To find the direction-of-travel based on a compass reading of 210 feet at 320° from a specific location:

Reading 210 feet at 320° Rotate the housing on the compass until the 320° mark lines up with the direction-of-travel arrow. Direction-of-travel arrow 320°

Reading 210 feet at 320° Rotate the entire compass until the compass needle lines up in the North alignment position. Direction-of-travel arrow Needle in the North Alignment Position

Reading 210 feet at 320° Holding the compass at eye level, use the direction-of-travel arrow to identify a distant landmark. Walk in a straight line as indicated by the direction-of-travel arrow for a distance of 210 feet to the recorded location.

Compass Reading 210 feet at 320°

Compass Use Note: All magnetic objects, such as belts, watches, keys, and other metal objects can interfere with the compass reading. Hold compass away form metal objects when taking a reading.

Compass Use Aerial maps are available through the Natural Resource Conservation Service or the Soil and Water Conservation District. Maps should be read with a compass on a flat, horizontal surface, away from metal objects. Readings may be taken from maps based on specific location and the direction to be traveled.

Compass Use The ability to use a compass effectively is an essential skill for wildlife managers, biologists, and other scientists who work outdoors. It is also a beneficial tool for the outdoor enthusiast.

Acknowledgements Dr. Joe Dettling, Associate Professor, Instructional Materials Service, Texas A&M University, researched and developed the information used in this PowerPoint Presentation. Jerry Dornak, Agricultural Science & Technology Instructor, Goliad High School, Goliad, Texas and Dr. Terry Blankenship, Wildlife Biologist, Welder Wildlife Foundation, Sinton, Texas, reviewed material used this PowerPoint. Christine Stetter, Artist, Instructional Materials Service, Texas A&M University, developed and illustrated this PowerPoint Presentation. Vickie Marriott, Office Associate, Instructional Materials Service, Texas A&M University, edited the material in this PowerPoint Presentation.