Explain Comparison of GNSS over conventional surveying methods.

Global Navigation Satellite Systems (GNSS) offer several advantages over conventional surveying methods, revolutionizing the field of geospatial data collection. Here's a brief comparison highlighting the key differences:

1. Accuracy:

• GNSS: GNSS provides high accuracy, especially with the use of Real-Time Kinematic (RTK) or post-processing techniques. Differential corrections and precise satellite positioning contribute to centimeter-level accuracy.
• Conventional Surveying: Traditional methods, such as total station and leveling, can achieve high accuracy but may require more time and labor-intensive procedures.

2. Efficiency and Speed:

• GNSS: GNSS allows for rapid data collection over large areas. With real-time positioning capabilities, surveyors can efficiently cover extensive terrains without the need for physical access to every point.
• Conventional Surveying: Traditional surveying involves setting up instruments at each survey point, leading to slower data collection processes, especially in challenging terrains.

3. Accessibility:

• GNSS: GNSS is highly versatile and accessible in remote or difficult-to-reach locations. It provides flexibility in data collection, making it suitable for various applications, including forestry, agriculture, and environmental monitoring.
• Conventional Surveying: Accessing certain locations for conventional surveying may be challenging, particularly in areas with dense vegetation, water bodies, or rugged topography.

4. Cost-Effectiveness:

• GNSS: While GNSS equipment may have higher upfront costs, the overall cost of data collection is often lower due to increased efficiency and reduced field time. GNSS eliminates the need for extensive field setups and repetitive instrument movements.
• Conventional Surveying: Traditional surveying instruments and labor-intensive procedures can incur higher costs, especially for large-scale projects or when dealing with challenging terrain.

5. Real-Time Data Collection:

• GNSS: GNSS allows real-time data collection and positioning, providing instant feedback to surveyors in the field. This feature is particularly valuable for applications requiring quick decision-making or adjustments.
• Conventional Surveying: Real-time data collection with traditional methods is limited, as it often involves manual measurements and subsequent processing in the office.

6. Flexibility:

• GNSS: GNSS offers flexibility in data collection scenarios, supporting various applications such as mapping, asset management, and disaster response. The same GNSS equipment can be used for diverse projects.
• Conventional Surveying: Traditional surveying methods may be more specialized and tailored to specific applications, requiring different instruments for different tasks.

7. Continuous Technological Advancements:

• GNSS: GNSS technology continues to evolve with advancements like multi-constellation support (GPS, GLONASS, Galileo, etc.), improved satellite coverage, and enhanced signal processing algorithms.
• Conventional Surveying: While traditional methods have seen advancements, the pace of innovation in GNSS technology surpasses many conventional surveying techniques.

In conclusion, GNSS has significantly transformed surveying practices by offering higher accuracy, efficiency, and accessibility. The continuous advancements in GNSS technology make it a versatile and cost-effective choice for a wide range of applications. While conventional surveying methods still have their place, GNSS has become the preferred choice for many projects due to its capabilities and advantages.