Monument type
Ring ditch with grave pit

Survey data
Area investigated: 45 m x 45 m
Resolutions:  1MP/m2 (a = 0,5m) : 2.025 m2                  

Array configuration: Twin-probe
Measuring instruments: Lippmann 4point light MC
Imaging software: SURFER (Golden Software)
Survey period: 17.08.2013

Comments
Stony or dry measuring surfaces often lead to incorrect measurements due to insufficient ground contact of the moving electrodes. In most cases, an error-free measurement image is not a mandatory prerequisite for correct image interpretation, but, especially for the interested layperson,  it makes it easyer to "read" the measurement image and is visually more appealing in the event of publication.

In the form of black and white pixels, the incorrect measurements usually occur individually and can be completely and safely removed with a good "despiking" filter (e.g. Snuffler). If two erroneous measurements do not occur singly, but directly one after the other or next to each other, they are not recognized as spikes by the "despiking" filter. In this case, they must be adjusted to the error-free neighboring measured values.
Other filters such as the Median filter can safely remove erroneous measurements too, but these filters not only eliminate the erroneous measurements, but also smooth out all values ​​of the measurement, which means that information is lost. In particular, small anomalies may become indistinct or disappear entirely. The use of filters always harbors a certain risk of information loss or even falsification, and requires experience on the part of the prospector.