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https://hdl.handle.net/11681/11699
Title: | Height variation along sea ice pressure ridges and the probability of finding "holes" for vehicle crossings |
Authors: | United States. Advanced Research Projects Agency. Hibler, William D. Ackley, Stephen F. |
Keywords: | Aerial photography Ice Ice navigation Pressure ridges Sea ice Surface effect vehicles Ground effect machines Vehicles |
Publisher: | Cold Regions Research and Engineering Laboratory (U.S.) Engineer Research and Development Center (U.S.) |
Series/Report no.: | Special report (Cold Regions Research and Engineering Laboratory (U.S.)) ; 197. |
Description: | Special Report Abstract: Height variations along sea ice pressure ridges were studied to determine whether low spots in the ridges persisted over long enough distances for a wide vehicle such as the surface effect vehicle to pass through them. Heights along eight pressure ridges varying in length from 0.9 km to 2.2 km were measured at 5-m intervals using aerial photographic data obtained over the Beaufort Sea. The probabilities of finding holes at the mean heights of the ridges and 0.67 m above and below the mean heights were calculated as a function of the hole widths using an autocorrelation function obtained from the height data. The curves obtained were in good agreement with passage probabilities calculated directly from the data. The results indicate that the probability of finding passage through a hole at least 0.67 m below the mean ridge height is less than 0.1 for holes greater than 10 m wide. It is concluded that a large vehicle such as a surface effect vehicle that cannot cross ridges at their mean heights will have to go around such ridges because low, wide holes do not appear with sufficiently high probability to make hole searching a useful method. |
Rights: | Approved for public release; distribution is unlimited. |
URI: | http://hdl.handle.net/11681/11699 |
Appears in Collections: | Special Report |
Files in This Item:
File | Description | Size | Format | |
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SR-197.pdf | 3.22 MB | Adobe PDF | ![]() View/Open |