Survey Datum Ledger

Survey Datum Ledger is a practical field archive for discovering, documenting, and studying survey markers, benchmarks, monuments, and historic geodetic reference points. Record each find with a photograph, marker type, identification details, and location data. Classify triangulation stations, elevation benchmarks, azimuth marks, boundary monuments, datum plates, witness posts, and other surveying references in one organized ledger. Explore technical details such as datum systems, ellipsoid information, stamped inscriptions, marker condition, construction type, and historical references. Document whether a marker is clearly preserved, weathered, corroded, damaged, or partially hidden. Use the interactive geodetic view to examine recorded points and visualize how reference markers relate across the map. Additional tools help estimate Earth curvature, atmospheric refraction, and apparent target displacement from line-of-sight measurements. An archive completeness indicator helps you spot missing information before an entry is finished. Built for surveyors, geodesy enthusiasts, map researchers, field explorers, and anyone interested in preserving the physical reference points that helped define our maps.