similarity transformation and the standard deviations are 
reported at three different scales in Table 4. 
Table 4. Standard Deviation Between Two Operators 
Film Scale Tube Scale Ground Scale 
Imag 
x = 8.4 ym 3.6 ym 14 m (30 
y = 9.7 4.2 17 
R = 12.8 5.5 22 
Imag 
It is apparent that image identification and measurement (31 
contributed a significantly larger variability (R = 22m) 
than map identification (max = 10m). 
Imag 
Image Adjustment to Ground Control. The coordinates of (15 
each of the four images were adjusted to ground control 
with each of the four transformations in turn. Table 5 
gives the resulting standard deviations. Note in the Imag 
table that x = y for the perspective and projective trans- (14 
formations. This results from the computer program 
(Bender, 1970) pooling the x and y residuals when 
calculating the standard deviation. 
a ge 
The similarity and affine transformations, being two- 0 f t 
dimensional, utilize UTM coordinates directly as input 
ground coordinates; the perspective and projective trans- Sele 
formations utilize space rectangular coordinates. Table 5 rbv 
indicates that residuals whose resultant standard deviation usin 
is between 90 to 100 meters can be expected from the prec 
similarity transformation and between 85 to 90 meters for to t 
the affine. By taking into account the three dimension- and 
ality of the ground control (perspective and projective seen 
transformations), the values drop down to between 30 and seen 
45 meters. Also, the two-dimensional transformations give expo 
residuals in the y direction which are approximately equal the 
to those in the x direction. foun 
cat i 
row 
MOSAICS were 
norm 
In the experiments with Landsat 3 RBV imagery as reported prod 
in the preceding section, horizontal control points were than 
identified on 1:24,000-scale paper maps and visually the 
transferred to a much smaller 1:500,000-scale RBV image. havi 
seal 
A possible improvement in geometrically controlling the idea 
RBV imagery is to use control which has been field 
identified by aerial photographs instead of using map Cont 
identified control. It is anticipated that more accurate Aeri 
positioning of control points onto the RBV imagery could aero 
be accomplished by direct transfer from field controlled Nant 
photographs, thus, effectively eliminating the error due cont 
to the visual transfer from the paper maps. In order to feet 
verify this expectation, a Landsat 3 RBV mosaicked image Cent 
base map of Cape Cod, Massachusetts, was controlled through this 
the use of aerial photographs. Landsat 3 RBV images were prob 
combined into a single mosaic as a 1:100,000-scale base for tria 
adju