Question

Tools View Model-Word output point. It is a positive, real number, and the default value of it is 2. (7) с By defining a higher (power) option, more emphasis can be put on the nearest points. Thus, nearby data will have the most influ ence, and the surface will have more detail (be less smooth). As the power increases, the interpolated values begin to approach the value of the nearest sample point. Specifying a lower value for power will provide a bit more influence to surrounding points a little farther away Since the IDW formula is not linked to any real physical process, there is no way to determine that a particular power value is too large. As a general guideline, a power of 30 would be considered extremely large, and thus of questionable use. Also keep in mind that if the distances are large, or the power value is large, the re- sults may be incorrect. A power of 2 is the standard valuc. 2. Assuming and IDW interpolation with a power of i. what is the weight of each of the colored cells to find the value of the green cell? Fill in the values. Consider the distance between the cell centers (basically using the pythagorian distance), so one cell up and one cell left (12+12)-2-1.414; one cell down and two cells left (12+22) N5-2.236 and so on Limiting the points used for interpolation The characteristics of the interpolated surface can also be con- trolled by limiting the input points used in the calculation of cach output cell value. The input can be limited by the number of sam- ple points to be used (VARIABLE) or by a radius within which there are points to be used (FIXED). Data W- 1. The measured value for a point is in the dis- tance to an unknown point is shown next to the lines be- tween the measured and unknown point, X (see below) Assuming an IDW power of 2, what is the value of X? Measured value can be elevation, precipitation, noise pol- lution level, anything meaningful.

Answer 1