1 x 1 DEGREE PROMINENCE LISTS

The columns are as follows: High Point X,Y,Z; Drop; Key Pass X,Y

The drop column shows the vertical distance that it is necessary to descend in order to reach a higher summit. This value is sometimes referred to as "prominence". It is derived from a Digital Elevation Model, derived from contours whose interval is typically 20 metres. The rms error in this value is typically about 10 metres, although there may be exceptions in areas of very high or low relief, depending on the quality of the source data.

The key pass coordinates locate the lowest point along the highest route from the subject summit to a higher summit. This point is sometimes referred to as its "prominence col". There is a one-to-one relationship between high points and key passes. The accuracy of this point is typically about 10", but, like the drop value, may be greater in high or low relief areas. If there are competing key passes that are of similar height, the computer has done its best to select the correct key pass from the input DEM data, but the error margin in the DEM data means correct selection cannot be guaranteed.

For some major high points, where distances to key passes can be very large, key pass locations are not shown, and the drop values shown may be substantially greater than the true values. A separate file "Supersummits" will follow soon.


DATA SOURCES

For Western and Northern Europe, including the Alps: contours derived from Russian military maps.
Elsewhere: 3" DEM data from NASA's Shuttle Radar Topography Mission in February 2000. 

Names were taken from US Geographic Names Information System gazeteer (usually shown in lower case), National Survey maps and Russian military maps. Where Russian maps were used the names had to be translated from the Cyrillic; spelling errors are likely. Lists of spelling or any other corrections are welcome.

Jonathan de Ferranti
26 July 2004