1. Below : Data from file NORTH2.TXT. Projection UTM-N13, spheroid Clark 1866, datum NAD27 (CONUS). This is an image of a 0.5m raster surface interpolated from the XYZ point data for a 200m x 200m study area centred on 106 deg.52.16'W, 32 deg. 39.04'N. The interpolation used only three data points, resulting in a rather smooth DEM image. Note that the DEM is based on elevations which include LIDAR returns from the mesquite bushes, as well as from soil!.
(i) area shown in leftmost image corresponds to the area shown in the previous image (above).
(ii) the area shown in the rightmost image corresponds to the area defined by the white AOI box in the leftmost image.
(iii) there is some misregistration between data points from NORTH1.TXT and NORTH2.TXT (original datafiles).
(iv) the anomalous division of the study area by a (non-existent) drop in elevation from E to W; this is thought to be owing to the difference in the elevations calculated from 2 different flight lines. The points cover (sequentially) first the left half of the rightmost image in a downward or southern direction and then the right half in an upward or northern direction. There is a third batch of points which covers the entire area with an even distribution of points, from the S to the N (bottom to top of image). The dark and light features protruding from the central division are artifacts of the interpolation where there is little or no data (in between 2 flight lines / scans?).
(v) the clumped distribution of points on the W-most scan appears to more closely resemble the actual distribution of the mesquite (on top of the dunes). The "fan" distribution on the E side (scanned from S to N) appears to bear no relation to the vegetation distribution.