DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 9-10/2003 str. 31 <-- 31 --> PDF |
D. Klobučar: OCJENA TOČNOSTI GEOKOD1RAN.IA OSNOVNE DRŽAVNE KARTE ... Šumarski list br. 9-10. CXXVII (2003), 457-465 Deviations of eight geocoded BMC sheets, i.e. 1040 control points are 5,00 m below in relation to equivalent amounts of analogous originals. Calculated maximum deviation on the X co-ordinate is 3,68 on sheet 34 and 3,46 on Y co-ordinate on sheet 35, while all the average deviations except for X co-ordinate (-1,65m) on sheet 34 are lower than 1,0 m in positive or negative sense. The accuracy ofgeocoding of digital orthophotographies was carried out by means of 43 control points. The deviations on X and Y co-ordinates for the majority of control points are lower than 5,00 m in positive and negative sense, with average deviation on X co-ordinate -2,21 m and -4,34 on Y coordinate. Significant deviations were found for 6 control points in maximal amount of-25,85 m on X co-ordinate (control point 31) and -38,45 m on Y co-ordinate (controlpoint 23). The accuracy of geocoding of digital orthophotographies is also satisfactory for application in the forestry of the Republic of Croatia because we are dealing with relatively minor deviations which refer to one point, i.e. object which has no dimensions, while all other objects almost entirely overlap with their projections on geocoded BMC either linearly or mono-dimensionally Based on the aspects of presented research results, as well as a whole other sequence of other application options of digital orthophotographies, it is our recommendation, to elaborate a digital orthophotography whenever management plans are made (regular revisions), providing, if possible, that the aerial photos be made in a bigger scale and the control points cover entire photos, which would diminish observed mistakes. Key wo rds: digital orthophotographies, Basic Map of Croatia (BMC), geocoding, cyclic aerial surveys, digital terrain models (DTM). |