ISPRS, Vol.34, Part 2W2, “Dynamic and Multi-Dimensional GIS", Bangkok, May 23-25, 2001 
134 
Q(x) = a 0 +a i x + ... + a m _ 
Then 
The correlation between t and several channels’ reflectivity (Ri) 
or radiant lightness can express as follows: 
S = A + Y j B,R, +c,r 2 , 
/=1 
A, B, Bi, Ci are constant 
According to the result of a certain thickness of oil film, 
analysis reflectivity and the least square method and the range 
of ware length in all channels we can get a relative value of 
every certain thickness of oil film in all channels. 
R , = A, + B (f 1 R(A)dX) 
JA. n 
Landsat has seven channels, NOAA has five ones. So 
&tm — ^ ^ BjR-i 
/=] 
Based on the sample data we can construct different oil film 
feature data line, and build discriminating function:(fig. 2,fig.3, 
Fig. 2: the Featured-Data-Line-- Window of heavy diesel oil 
Fig.3: the Featured-Data-Line-- Window of lube 
Fig.4: the Featured-Data-Line- Window of crude oil 
Fig. 5: the Featured-Data-Line- Window of light diesel oil 
Because reflectivity of oil film change along with thickness of it 
in certain extend, this change has nothing to do with 
wavelength but only decided by the thickness of oil film. The 
different thickness of same kind of oil film just likes a series 
locomotion locus, which only has level locomotion along Y 
coordinate axis direction. So we decide to make a window in 
the center of featured data line. The size of it is an alterable 
parameter that can be decided by the quantity of spilled-oil and 
the situation of incident. By doing this featured data line 
become a range of Grey intensity. 
Discriminate the Grey intensity of all pixels to make sure if the 
Grey intensity are belong to this windows’, if it is information of 
oil film can be extracted. 
4. Software of Auto-extracting the Sea Oil Information and 
result analysis 
This software is exploited based on VC6.0++, every function 
has three parts: input data file, process data file and output 
result file. The data files include two categories that are 1 df 
that belong to NOAA and data that belong to TM. We process 
data file by the method of Featured-Data-Line- Window (FDL-