Short Answer:
The difference between trilateration and triangulation lies in what is measured to determine positions. In trilateration, distances between known and unknown points are measured, and positions are found using these distances. In triangulation, angles between points are measured from a known baseline to calculate unknown positions using trigonometry.
Trilateration relies on distance measurements only, while triangulation depends on one known baseline and angle measurements. Both are used in surveying and mapping, but trilateration is often used in GPS systems, and triangulation is commonly used in land surveys and geodetic mapping.
Detailed Explanation:
Difference between trilateration and triangulation
In surveying and mapping, determining the location of unknown points is essential. Two popular methods used are triangulation and trilateration. While both involve geometric principles and are used in mapping, their core methods are different in how they collect and use data.
Triangulation
Triangulation is based on measuring angles and using a known baseline. The process begins by establishing a straight-line base of known length on the ground. Using angle-measuring instruments like a theodolite or total station, angles are taken from both ends of the base to an unknown point. Using the baseline and measured angles, the position of the unknown point is calculated using trigonometry.
Key features:
- Requires accurate angle measurements.
- Needs a known baseline.
- Common in traditional land and geodetic surveys.
- Suitable for covering large areas efficiently.
Trilateration
Trilateration, on the other hand, involves measuring distances only. No angles are measured. The method determines the location of a point by measuring its distance from three or more known points. With these known distances, the position of the unknown point is calculated using geometric formulas. This method is the basis for modern GPS systems.
Key features:
- Uses distance measurements.
- No need to measure angles or establish a baseline.
- Used in electronic and satellite-based surveying (e.g., GPS).
- Works well with electronic distance measurement (EDM) instruments.
Main differences between trilateration and triangulation:
- What is measured:
- Triangulation: Angles + one baseline.
- Trilateration: Distances only.
- Tools used:
- Triangulation: Theodolite, total station.
- Trilateration: EDM devices, GPS receivers.
- Applications:
- Triangulation: Traditional land surveys, topographic maps.
- Trilateration: GPS, remote sensing, geolocation systems.
- Accuracy dependence:
- Triangulation: Depends on accurate angle measurement.
- Trilateration: Depends on accurate distance measurement.
Conclusion
The key difference between trilateration and triangulation is that trilateration uses distances to find positions, while triangulation uses angles and a known baseline. Both are essential in surveying, with trilateration widely used in GPS technology and triangulation in land and topographic mapping. Understanding this difference helps in selecting the right method for a specific survey requirement.