Measurements of Horizontal Distances Flashcards
counting the number of steps or paces in a
required distance
Pacing
length of a step in walking
Pace
double step (1 stride = 2 paces)
Stride
in meters/pace
* Length of one’s pace
Pace Factor
Records the number of steps made on the body’s
movement
Pedometer
Strapped to the leg of the pacer
Registers a pace by impact each time a foot touches
the ground
Passometer
The use of a graduated tape is the most common
method of measuring horizontal distances
Distance by Taping
measurement of distances using chains
Chaining
persons undertaking measurement using
chain
Chainmen
- Also called Tacheometry
- Based on the optical geometry of the instruments
employed and is an indirect method of measurement
Distance by Tachymetry
- Introduced by James Watt (1771)
- Relative precision: 1/300 to 1/1000
- Consists of a telescope with two horizontal hairs
(stadia hairs) and a graduated rod (stadia rod)
Stadia Method
- Bar: 2 meters long
- Horizontal distance is measured by setting up the
subtense bar at the distant station and measuring the
horizontal angle subtended by the distance between
the two targets using a theodolite.
Subtense Bar Method
Unknown distances may be determined through their
relationship with known distances geometrically.
Distance by Graphical and
Mathematical Methods
- A device attached to a wheel for
measuring surface distances - precision: 1/200 (on fairly level
terrain)
Odometer
- A more portable and self-contained
measuring device than the odometer - Consists of a small wheel attached to
a rod and handle
Measuring Wheel
