The horizontal measurement in surveying refers to the distance between two points as if measured on a perfectly level plane, disregarding any differences in elevation.
In essence, surveyors are interested in the "flat" distance between locations. Even if one point is much higher than another, the horizontal measurement is the distance you would get if you projected both points straight down onto a flat surface and then measured the distance between those projections.
This is important because:
- Mapping: Maps represent the world as a flat surface. Horizontal distances are crucial for accurately portraying features on maps.
- Construction: Building plans rely on horizontal measurements to ensure structures are correctly positioned.
- Land Division: Property boundaries are defined using horizontal distances, which are critical for legal descriptions.
Think of it this way: If you're measuring the distance between two trees on a hill, you wouldn't use the actual slope distance measured along the ground. Instead, you would determine the horizontal distance, which would be shorter because it accounts for the elevation difference.
Surveyors use various instruments and techniques to accurately determine horizontal distances, including:
- Total Stations: These electronic instruments measure angles and distances, and they can automatically calculate horizontal distances.
- GPS (Global Positioning System): GPS receivers can provide horizontal coordinates, allowing for the calculation of distances between points.
- Traditional methods: Incline distances, vertical angles and trigonometric function or slope correction techniques are used to calculate horizontal distance.
Therefore, the horizontal measurement is a fundamental concept in surveying, ensuring accurate representation and measurement of spatial relationships on a level plane.
