Let's consider two principles of search valuable obektov in the field with use metallodetektora. We will assume that the size of a field is that that for one hour the ring of yours metallodetektora can pass 10 % of the area of a field. The first of considered types of search consists that the operator freely walks up and down across the field in any order, without doing a ring of overlapping of the previous pass. The second type of search - search on setkoobraznomu to a route from 50 % overlapping of the previous pass.
By casual search you start to cover a field with speed of 10 % at an o'clock. But as you go across the field in a random way, you start to encounter areas which already have passed earlier and speed of survey of the new areas decreases (the Red line). Mathematical expression for a share of the surveyed earth is [1-e-rt].
Use setkoobraznogo a route from 50 % overlapping of the previous pass gives 5 % of the area of the surveyed field at an o'clock. (A dark blue straight line)
But the reason for overlappings of the previous pass by a ring consists that radiation under it goes not directly downwards at ring edge, and flanches a little, sharoobrazno. Therefore for one wave you do not cover with a ring all obem soil under a ring. The single wave covers only 67 % obema soils. On the other hand, 50 % overlapping of the previous pass cover about 92 % obema soils under a ring. Therefore to consider simply passed area it will be not quite fair. It will be better to consider surveyed obem soils.
Obem the surveyed earth by casual search it is approximately equal [1-e-.67rt] (the Red line).
Obem the surveyed earth by regular search from 50 % overlapping it is equal [x. x. 10 x t] (the Dark blue straight line).
Pay attention that half of territory is not surveyed yet, casual search covers the field area faster.
Therefore if you have enough time for detailed inspection of all field, regular search in a grid with overlapping of passes will pay back itself. But if you have only a pair of clocks, casual search can be so effective.
Other strategy consists that if at you in a stock some hours, to use regular search without overlappings of waves. Probably, about such approach still anybody also did not hear, as everyone knows as important to block the previous wave of a ring.
> The first 10 hours you survey obem soils with speed of 6.7 % at an o'clock. Then, when after 10 business hours you have covered all area of a field, you start to survey again the same field moving at right angle to the previous route. In the following of 10 hours you will survey new obem with speed of 1.7 % at an o'clock (the Lilac curve). But after 17 business hours strategy of 50 % of th overlapping wins.
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