Short Answer:

Plane table surveying has the advantage of allowing both observation and drawing to be done on-site, which saves time and reduces the chances of recording errors. It is simple to use, cost-effective, and suitable for small, open, and clear areas. Errors can be spotted and corrected immediately during the survey work.

However, this method also has disadvantages. It is less accurate compared to modern instruments, cannot be used during bad weather, and requires a stable and flat surface for setup. It is not suitable for large-scale or very detailed surveys due to its limitations.

Detailed Explanation:

Advantages and disadvantages of plane table surveying

Plane table surveying is a traditional and practical method used for preparing maps and site plans directly in the field. It is mostly used for small-scale work where quick and direct plotting is required. Like all methods, it comes with its own set of advantages and disadvantages, which should be considered before choosing it for any survey project.

Advantages of plane table surveying:

1. Immediate plotting
   One of the biggest advantages is that the map or plan is drawn while standing at the site. This reduces the chances of mistakes that may happen while transferring data from the field book to the drawing sheet later.
2. Simple and low-cost method
   The instruments used (plane table, alidade, tripod, etc.) are basic, easy to use, and inexpensive compared to total stations or theodolites. No special training is required for basic operations.
3. Quick execution
   Since there is no need to record readings and later convert them into drawings, the process is faster. The surveyor can complete both observation and drawing in one visit.
4. Error detection on the spot
   Because the drawing is done immediately, any mistake or inconsistency is visible at once and can be corrected without delay. This helps avoid repeat visits to the site.
5. Clear understanding of terrain
   The surveyor observes the features and marks them directly, helping them understand the area better. This is useful in basic planning or rough layout work.
6. Good for educational and small field projects
   Plane table surveying is widely used in colleges and for simple projects like village maps, small land divisions, or simple topographic surveys.

Disadvantages of plane table surveying:

1. Less accuracy
   The method does not provide highly precise measurements. It is less reliable for large-scale or engineering-grade work where high accuracy is needed.
2. Weather limitations
   It cannot be used in rainy, windy, or very hot conditions. Drawing paper may get damaged, and sighting becomes difficult in poor visibility.
3. Difficult terrain
   Setting up a plane table on uneven or sloping ground is difficult. A flat surface is needed for proper leveling and stability.
4. No permanent record of measurements
   Since no field book is used, there is no separate record of measurements, which may be needed later for checking or verification.
5. Bulky to carry and set up
   The tripod, drawing board, and other tools are not very portable and may be hard to handle on steep hills or remote locations.
6. Not suitable for night surveys
   The method depends heavily on visibility. Therefore, it is not suitable for night or low-light conditions.

Plane table surveying should be used where high precision is not required, and conditions are favorable. For complex or large-scale surveys, modern digital methods are better choices.

Conclusion

Plane table surveying offers several advantages like simplicity, low cost, and direct on-site plotting, making it ideal for small and quick survey tasks. However, it also has limitations in accuracy, weather resistance, and usability in difficult terrain. It is best suited for basic surveys and educational purposes.