Suunto Tandem manual Triangulation

The instrument can also be used for triangulation, see Fig 6. The bearings obtained from the main scale are 0° against the hill and 64° against the curve of the road, or 180° and 244° on the reverse scale. Your own location is indicated by the intersection point of these two lines. When performing very accurate posi- tioning tasks the bearings obtained have to be corrected for local declination.

The co-tangent table at the back of the Tandem can be utilized for distance calculations, and especially for locating position in cases where two landmarks are visible at a narrow angle. This procedure is also illustrated in Fig. 6.

t

90°

0° 64° 15°

Fig. 6. Triangulation

The angle between the curve of the road and the oil derrick is 15°. A line is drawn at a 90° angle to the 64° bearing line from the curve of the road toward the oil derrick bearing line. The distance, as measured on the chart, is 1.6 km [1 mile]. Then your position is cot 15° x 1.6 km = 6 km [cot 15'° x 1 mile = 3.7 mile] along the corrected bearing line of 64°.

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