signal, even if changing VDI in the direction of iron due to the possible
presence of surface debris.
If, nevertheless, excavation of the signal has begun, raise the sensor of
the device above the pit and smoothly, but quickly lower it into the pit
and immediately lift it back. If there is a metal target, the hodograph
from it for both movements is fixed on the screen. It will be either a
hodograph from a sufficiently large iron, or from a non-ferrous target. In
the case with the lens, the difference in the hodograph during horizon-
tal scanning and vertical lowering-lifting is very strong. If with hori-
zontal scanning it is a clear target hodograph, like a large non-ferrous
target, then when lowering / raising the hodograph is “blurred” over
the ground in the non-ferrous and iron sectors. This is a clear sign of a
ground lens.
Of course, if you dig not only two-way explicit signals, but also all the
bursts, catching every “suspicion”, as when searching in the normal
mode, then it is possible to dig out something valuable on such a signal.
But taking into account the excavations, not by one- two shovels, but by
a meter, or even more, the efficiency will be low, and fatigue and disap-
pointment will come very quickly. Remember that in the vast majority
of cases, a large target will give a clear noticeable two-way signal. From
this and begin your development of DP. When you master it enough to
in most cases understand what is in the ground with a particular signal,
only then, soberly assessing your strength, perhaps to expand under-
standing, it is worth experimenting with excavations of “controversial”
signals.
And please bury the dug holes!
USING THE HODOGRAPH FOR IDENTIFICATION
We have previously mentioned about using the hodograph for identify-
ing targets. But what is the hodograph and what it is for?
Amplitude and phase depend on the electro physical parameters of ob-
jects such as conductivity, magnetic permeability, depth, geometry, etc.
To accurately describe the nature of the received signal from an object
is very difficult, given the variety of influencing factors. However, it is
possible to point out some general patterns.
Earlier, we mentioned that the signal is a vector quantity characterized
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