# Full text: Mapping without the sun

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case of complete independence by means of the
relative entropy or the Kullback-Leibler measure.
2.2.4 Improved hill climbing method: In each pyramid-
layer search process, we use improved hill climbing search
strategy to reduce the number of calculation of correlation
coefficient and guarantee the searched extremism point is the
extremism point of the whole area.
The traditional hill climbing method is an illuminating search
strategy. By using illuminating information guidance, to let the
search toward object and improved the efficiency of the
resolution process.
Nevertheless, due to its limitation, the hill climbing search is
possible of obtaining the local extremism point. If we have
illuminating information’s guidance, mountain-climbing
method could solve the problem as soon as possible. However,
if there is only one apex, the mountain-climbing method could
promise to find the top, on the other hand, if there are many
apexes, and the initial search point is in non apex area, the
mountain-climbing would be very hard to get the real apex.
Therefore, by improving the position of the initial point would
help the hill climbing method get the optimizing apex point
surely. In fig. 3 the improved search method make the search
start from the initial place point position and follows the X
direction that is POA to have a whole search. And find the
whole apex in the X direction PI, and then follows P1B
direction to have a whole search, to get the whole apex in the Y
direction P2. This point has a very high possibility of be the
main apex in this area. When search in X and Y direction, we
could search with certain step length. It is unnecessary to
calculate the correlation coefficients of every point, as long as
the initial searching point is in the area of the main apex. Then,
we can start search again in the original place by using
traditional mountain-climbing method to calculate the main
apex S2 quickly [12].
2.2.5 Eliminate the wrong match point: In this paper, we
eliminate the match points which are larger than three RMS, by
using two dimensional polynomial geometry relations of the
generated corresponding points.
2.3 Rectification and Registration based on TIN
In this part, we first create the Triangulated Irregular Network
Fig.3. Improved hill climbing method
(TIN) by minimum distance method[10] in the two images.
For each of the large number of triangles has three tie points
Xi ,Yi ) ,( X' i ,Y' i ) ,i = 1 ,2 ,3 ,which can be used to
calculate affine parameters:
X' = aO + al X + a2 Y
Y' = bO + bl X + b2 Y (3)
Three points can get six equations, than we can calculate
aO ,al ,a2 and bO ,bl ,b2 with which we can correct theAP'
.IP' 2 P' 3 on the reference image to API P2 P3 on the
master image. The process of rectification as follow:
Fig.4. the process of resampling
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