Remote Determination of Bridging/Fording Sites

Remote analysis of terrain features is invaluable to military units. Prior knowledge of the maneuver geography can be a great force multi-plier, allowing accurate forward planning for force projection and placement of assets. The common tools of the Army Terrain Team analyst include geographical contour maps, usually with the best contour interval being 20 ft, and aerial imagery, both visible and infrared. Together, these offer good general information about the terrain adequate for large-scale movement and placement of forces. However, the execution of a river crossing requires detailed knowledge of the topography immediate to the river. Vertical and horizontal resolutions of 1 to 2 ft. are necessary, based upon vehicle vertical step and slope negotiation capabilities. This study looks at the capability of the terrain analyst to accurately determine suitable river crossing sites based upon our current remote assessment tools. The 66th Engineer Detachment, Fort Drum Terrain Team, remotely studied 121 miles of river in Vermont and New Hampshire using available contour maps and aerial imagery for suitable crossing locations. The study areas were then inspected on-site to assess the actual suitability of the selected crossing locations. There was a 16% overall success rate for remotely determining bridging/fording sites. The predominant factor in site rejection was the vertical height and/or slope of the riverbanks.