RTK GNSS Survey Services in Bangladesh

How accurate is RTK GNSS?

In good conditions, RTK positions are centimeter-level horizontally, and vertical accuracy is usually somewhat looser. Good conditions mean a clear view of the sky, a stable correction link and a short distance to the base station. Modern receivers track several satellite systems, including GPS, GLONASS, Galileo and BeiDou, which helps in partly obstructed areas.

Accuracy degrades with signal reflections from nearby walls and metal roofs, tree canopy and distance from the base. A good survey therefore checks itself: we re-observe some points at a different time, measure known control and report the results. A fixed solution shown on the controller is not proof on its own.

Why does the coordinate system matter?

GNSS works natively in WGS84 latitude and longitude, but engineers draw in meters on a flat grid. In Bangladesh that usually means UTM, zone 45N or 46N depending on longitude, or the Bangladesh Transverse Mercator (BTM) grid used by several government agencies. Mixing grids without a proper transformation puts drawings in the wrong place.

Heights need the same care. GNSS measures height above the ellipsoid, which is not the same as height above mean sea level. We tie levels to a benchmark or the datum your designer specifies, such as the PWD datum often used for flood levels, and state the datum on every drawing.

When should you use RTK on a project?

Use it early. A control network surveyed with RTK at the start gives every later survey, drone flight and setting out job the same reference. It suits plot boundaries, open land for a factory extension, utility routes and large earthworks, where walking a rover across the site is far quicker than traversing with a total station.

Where the site is built up or wooded, we use RTK for control in open spots and finish the detail with a total station from those points. That combination keeps the whole drawing in one coordinate system without losing accuracy in difficult corners.