SPECIAL PUBLICATION NO. 39
method. Rectification of the Hilliard NE area using
10 GCPs achieved a RMSE of two meters along both
x- and y directions, which exceeded Interim Accu-
racy Standards for Large-Scale Maps (IASLSM) for
maps at scale 1:12,000. The results from the Gross
area with more relief were within one meter to meet
IASLSM for maps at scales of 1:24,000 when 29
GCPs were used. More accurate results can be
achieved if the ground coordinates of GCPs can be
provided through a field survey.
The methodology developed in this research
allows a less skilled operator to determine accurately
the image coordinates of a GCP. The further im-
provement of the algorithms will provide important
means for automated/semiautomated rectification.
285