Carrying out drone based photogrammetry/lidar survey for detailed engineering of project including alignment, leveling, geotechnical investigation, hydrological investigations, preparation of plans, l and x-sections, general arrangement drawings (gad) of bridges, bill of quantities and other ancillary activities and preparation of dpr in connection with (1) final location survey (fls) from chhapra - kopa samhota 3rd line incl. one additional running line at tekniwas & kpoasamhota both & one rake handling line at tekniwas (10.46 km.), (2) final location survey (fls) from kusmhi - baitalpur 3rd line section (29.37 km.), (3) final location survey from domingarh - khalilabad 3rd line incl. down extended loop line at jagatbela (30.00 km.) & (4) final location survey from bhojipura - bareily twin single line section (19.31 km.) of north eastern railway.