There are several surveying and geomatics principles covered in the optional subject. These principles are crucial for understanding the various methods and techniques used in surveying and geomatics. Here are some of the key principles covered in this subject:

1. Measurement and Error Analysis:
- Measurement theory and techniques are covered, including methods for measuring distances, angles, and elevations.
- The concept of errors in measurements and their analysis is discussed, including sources of errors and methods for error reduction.

2. Surveying Instruments and Techniques:
- Different surveying instruments and their uses are covered, such as theodolites, total stations, and GPS receivers.
- Techniques for conducting surveys, such as plane table surveying, compass surveying, and trigonometric leveling, are discussed.

3. Geodetic Surveying:
- Geodetic surveying principles are covered, including the concept of datums, coordinate systems, and map projections.
- Techniques for establishing control networks and conducting precise leveling are also discussed.

4. Photogrammetry:
- The principles of photogrammetry, which involves the measurement of objects using aerial photographs, are covered.
- Topics include stereoscopic vision, image interpretation, and the use of photogrammetric software for data processing.

5. Remote Sensing:
- The principles of remote sensing, which involves the acquisition of data from satellites and aircraft, are discussed.
- Topics include different remote sensing platforms, image interpretation techniques, and applications of remote sensing in various fields.

6. GIS and Cartography:
- The principles of Geographic Information Systems (GIS) and cartography are covered.
- Topics include spatial data models, data acquisition and integration, spatial analysis, and map design principles.

Overall, the optional subject of surveying and geomatics provides a comprehensive understanding of the principles and techniques used in surveying, mapping, and geospatial analysis. It equips students with the knowledge and skills required for conducting accurate surveys, analyzing spatial data, and creating maps and other geospatial products.