Conventional Land Survey using DGPS, Total Station, Auto Level

Total Station, DGPS and Auto Level Survey

Engineering Surveying using Total Stations & DGPS

Engineering Surveying means the work of surveyors on civil engineering projects. We use a wide range of instruments to prepare topographic drawings with state-of-art of on-site work. The most common of these will be the Total Station, GPS and Auto Level or Digital Level.

We first establish a network of control points around the site in a position predetermined with engineers and supervisors on site. The control points need to be in useful, safe and accessible areas but also in areas where they will not be disturbed. When the detailed survey work commences, our surveyors measure each and every object in the project site, take level at required interval, prepare site sketches, collect culvert & Bridges inventory. The data are stored in the instrument with a unique code in the format of ID, X,Y,Z,Code.

Once all the survey data has been recorded, the Engineering Surveyor will process the data, complete calculations and finally complete the documentation. The as-built documentation shall be presented on a drawing, spreadsheet, and word reports.

DGPS RTK Survey

Differential GPS to obtain precise positions of unknown points by relating them to known points. The baselines represent a three-dimensional line drawn between the two points occupied by each pair of GPS antennas. The post-processed measurements allow more precise positioning, because most GPS errors affect each receiver nearly equally, and therefore can be cancelled out in the calculations.

Differential GPS measurements can also be computed in real time by some GPS receivers if they receive a correction signal using a separate radio receiver, for example in Real Time Kinematic (RTK) surveying or navigation.

The basic objective of a topographical survey is to determine three-dimensional positions of all ground features in the form of x, y, and z coordinates with respect to a defined reference system to generate an accurate digital terrain model of the project area for the preparation of strip plan, designing, working out improvements, rehabilitation, and up-gradation of the project, design additional facilities, alterations and additions for its development.