# Full text: Proceedings, XXth congress (Part 8)

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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B-YF. Istanbul 2004
following equation. The equation was derived from the
coplanarity condition equation.
B 0 0
yw
u v wi=B 120
; y ow
H V w
(1)
Where 48 , V, W are coordinates of image point a in
Y ru z - ' A, y : =
S— AYZ spatial coordinate system. # , Ÿ , V are coordinates of
image point a’ in | \$ -XY Z spatial coordinate system. B is
photo base, and the coordinates system is just described by
figure 2.
Supposing photo base B is collinear with the X axis of the
coordinate system, so the component of photo base B is 0 in the
direction of Y and Z. So equation |! can be denoted as follow.
Flp.x,0 0 x)= , ; =0
(2)
Linearization of equation 2 is as follow.

Zz
Ziviy
NY
gn pi V
B
(u,v,0) y (uv J |
Figure 2. Relative orientation relationship
GF
F(o.x,o 0k )= F SE oet AD RU au eU air MANY =0
op Op ow
Where, Q? , K are pitch and yaw of left image, Q' ; K' are pitch
/
and yaw of right image, €^ is the roll angle of right image
relative to left image.
Using a number of tie points the absolute values of pitch and
yaw can be calculated through this relative orientation
algorithm. But the absolute roll angles cannot be computed only
using two adjacent images. So the absolute yaw angle can be
computed by one of these two ways, one is to import at least
one GCP. The other, when there are four or more images which
OK OK
have longitudinal overlap and lateral overlap, the yaw angle of
left or right image can be computed by using of these four-
image-overlap points. And so as to implement the attitude
angles computation without GCP. So after gotten the satellite’s
position by GPS and the attitude angles using the images
overlap characteristic, the targets’ can be positioned. The flow
is described as follow(see figure 3.).

Corresponding points
surveying in overlap area

Attitude computation

Y

Corresponding image

Surveying the target in
both images

——» Attitude correction
I
I
I . .
-_a points surveying
+ 1
1

Scale coefficient computation
NED RT A en I
v . Surveying the target in |
: left image :
1 1
i 1

Y I

Target coordinate computation

Figure 3. targets' positioning flow
110
Interr
———
Two
The
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