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🌊 Hydrographic Survey
0/5 steps
STEP 1
Tide Gauge Setup
STEP 1 — SET UP TIDE GAUGE Install and operate tide gauge. Why we do this: Water levels change constantly. Soundings must be corrected to a common datum (chart datum). Setup: • Install tide gauge at fixed location • Record readings every hour • Note time of each reading • Mark gauge zero elevation
STEP 2
Positioning System
STEP 2 — SET UP POSITIONING Configure GPS for boat positioning. Options: • RTK GPS on boat • Total station shore setup • Acoustic positioning Requirements: • Position accuracy < 1m • Time sync with sounder • Record fix numbers
STEP 3
Sounding Lines
STEP 3 — RUN SOUNDING LINES Collect depth data along planned lines. Planning: • Parallel lines across survey area • Line spacing based on requirements • Run lines perpendicular to shore For each fix: • Record time • Record position • Record raw depth
STEP 4
Data Reduction
STEP 4 — REDUCE SOUNDINGS Apply tidal corrections. In METARDU Hydro Tools: → Enter tide gauge readings → Enter sounding data → Apply tidal correction Formula: Corrected Depth = Raw Depth - Tide Height Chart Datum depth = Corrected Depth - Datum Offset
STEP 5
Generate Chart
STEP 5 — OUTPUT RESULTS Create bathymetric chart. In METARDU: → View cross sections → Generate contours → Export to CAD/DXF Deliverables: • Depth soundings table • Bathymetric contours • Survey report