AY. YY TY al 
2 TS Om 
CS CC. — 
Figure 3: Overlay (addition and rescaling) of the two map- Figure 4: Resampling coordinate displacement image for the 
registered images of 1991 and 1995 (using thin-plate spline ^ 1995 data between global polynomial and local AKIMA reg- 
registration with U(r) — r? Inr). istration (black is vanishing, white is maximum difference, 
  
GCPs marked as white crosses). 
  
  
  
  
  
  
  
  
VARIANCE OF SECOND PRINCIPAL COMPONENT (‘CHANGE’) 
Spectral Band Number i 1 2 3 4 5 6 7 8 9 10 
Center Wavelength [um] 0.435 0.485 0.560 0.615 0.660 0.723 0.830 0.980 1.650 2.215 
GLOBAL POLYNOMIAL 
Absolute Variance of 2. PC: | 26.64 5842 72.58 103.11 113.80 151.74 533.08 503.06 256.99 264.20 
Relative Reduction of 2. PC Variance: mean + stdev.: 
AKIMA LOCAL POLYNOMIAL | -4.3% -74% -7.0% -6.6% -5.6% —54% -71% -93% -9.2% _43% -(6.6 + 1.8)% 
AFFINE + r2In7 | -54% -8.4% 91% 91% -72% -87% -94% -11.9% -120% -6.0% ; -(8.7 + 2.2)% 
AFFINE +7 | 49% -85% -7.9% -82% -59% -6.8% -99% -13.5% 12.5% -53% | -(8.3 € 2.9)96 
v1+r? |-10% -32% -12% -06% —01% +1.6% -18% -2.2% +2.4% +4.9% | -(0.1 x 2.4)96 
POLYNOMIAL + V1 +r? | -52% -93% -9.3% -88% -78% -75% -8.1% -10.1% -10.7% -53% | -(8.2 X 1.8)96 
  
  
Table 1: The variance of the second principal component is considered as the amount of ‘change’ between the two images of 
the scene. Erroneous ‘change’ is reduced by improved registration techniques. 
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International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996