Resolving Mouza Sheet Conflicts: The Math of Georeferencing CS, SA, RS, and BS

Vlog Overview & Transcript

Property boundaries in Bangladesh are governed by cadastral maps called Mouza sheets. These maps were drafted across different decades under varying survey regimes: CS (Cadastral Survey 1888-1940), SA (State Acquisition 1956-1963), RS (Revisional Survey 1965-1998), and modern BS (Bangladesh Survey 1998-present).

Because legacy maps were drawn by hand on paper using units like links (Gunter's Chain), they warp, stretch, and contract over decades due to atmospheric humidity. When modern real estate developers buy land, overlaying a GPS boundary onto a warped paper map introduces substantial overlap conflicts.

Our georeferencing pipeline uses a mathematical Helmert coordinate transformation model (affine scale, translation, and rotation matching) to correct paper distortion. We first locate historical benchmarks in the field, map them using Total Stations, and cross-reference them with geodetic control monuments established by the Survey of Bangladesh (SOB).

We digitize original mouza sheets at high resolution and run scale-invariant feature extraction to identify original plot boundary lines. This allows us to superimpose the historical plot limits onto modern satellite imagery and GNSS coordinates, resolving overlap conflicts with transparent, court-admissible surveyor reports.