SECONDARY SURVEY, CONTROL POINTS, AND HYDRO GRAPHIC DEVELOPMENTS
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✎ Suggest a correctionDescribes secondary signals, building, sounding and wire dragging operations, tide and current observations, photogrammetric compilation, magnetic observations, and other miscellaneous survey work.
Sources
- usgov-av-1974 — title, year, creator, length, color, sound, description
Record added 2026-07-01 03:46:06 · Suggest a correction