Measures Home

In this section you will find definitions and explanations of various measures used on haramfjell.com. These include Altitude, Primary factor, Secondary factor, Vertical metres, and Distance.

My sources for stating a mountain's measures are several; for Norwegian mountains I tend to rely on Statens Kartverk. In some rare cases the number shown on maps are definitely wrong; a typical example is when the height shown on the map is stated for a trigonometric point, which clearly is not located at the summit. In these cases I rely on my personal GPS measurements and/or observations on-site and/or other sources.
For countries outside Norway I use whatever information I can get hold of; printed maps, digital maps, personal GPS measurements, and information on the Internet.
A hike's distance and number of vertical metres I usually find by analysing the GPS tracks.

Altitude (alt.)

I am using both "altitude" and "height" as the term to describe how high a point is above sea level.

Primary factor (PF)

The "simple" definition of primary factor is "the least vertical distance you have to descend in order to get to a higher point".
Primary factor, often called prominence, is crucial in order to defined whether a given point is a mountain or not. If you assume a long ridge with a lot of bumps on it you are likely to wonder how many mountains there are along this ridge; primary factor is the measure to apply to find the answer. If you have to descend at least 100 vertical metres from a given bump in order to get to a higher point then the bump in question can be regarded as an independent mountain. In some areas of the world a primary factor higher than 100 metres is used to define the list of independent mountains.
As a rule of thumb you can assume that the higher the primary factor the better the view, but there are definitely exceptions.

Secondary factor (SF)

The secondary factor of a mountain is the horizontal distance from the mountain's summit to the nearest point of equal altitude.
If the Secondary factor of a mountain is high then there is a long distance to another piece of land obstructing your views, and hence your are likely to see a large area of land from this mountain.

Vertical metres (vm)
The total number of vertical metres ascended. For a round-trip this will include the vertical metres for both the ascent and the descent (if any).

Distance (dist.)

This is the horizontal distance hiked.