Topographic maps and sketch mapping . HuMr ^JW^^ L ]Tmm£. Fig. 45.—Resection Method. in the field is selected and the observer paces, or measureswith a tape, the distance to it and notes the direction witha compass. He then starts at this object as shown on themap and plots back the distance with the reading scale inthe proper direction, thus locating the point in method, known as resection is illustrated in The map is placed in a horizontal position, preferablyon a drawing board, and is correctly oriented. Two objects FIELD USE 79 A and B visible in the field and show
Topographic maps and sketch mapping . HuMr ^JW^^ L ]Tmm£. Fig. 45.—Resection Method. in the field is selected and the observer paces, or measureswith a tape, the distance to it and notes the direction witha compass. He then starts at this object as shown on themap and plots back the distance with the reading scale inthe proper direction, thus locating the point in method, known as resection is illustrated in The map is placed in a horizontal position, preferablyon a drawing board, and is correctly oriented. Two objects FIELD USE 79 A and B visible in the field and shown on the map as a andb are selected. A ruler is placed on the map so that its edgepasses through one of the objects, say a, and the ruler isturned so that it also points in the direction of this objectin the field, A. An indefinite line is drawn for this position,ac, and the same procedure is followed for b and B, giving theline bd. The intersection of these lines at e is the locationof the observer. Similar methods can be used to plot on themap the l
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectcartogr, bookyear1920
