The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part Bl. Beijing 2008 
R L C = R L b -R b c = R y {(p) R x {co) R z {K) (2) 
R b L = R,{0)-R x {*)-*A¥ ) 0) 
III In formula (2), the other parts can be all computed 
except R b c , and the elements in R b are just the deviation angle 
error, which are we want to calculate. After expanding this 
formula, we can get a set of observation equations AX — L 
about (a x ,CX v ,a z ) , where X = (CC X , OL y , CC Z ) T is the 
unknown quantity, and the corresponding error equations is 
V = AX — L . For each image i, a set of 
= AjX — L i can be list out. According to s the related 
knowledge of surveying adjustment, we can 
know X = (A T • A) 1 • A T • L . Supposed that there are two 
images, then 
Image 
Humber 
Original Data for IMU in Terrestrial Photogrammetry 
Coordinate System 
Phi/deg 
Omega/deg 
Kappa/deg 
158 
-1.612115 
-0.439668 
2.813874 
157 
-1.582804 
0.263801 
2.901808 
156 
-2.066439 
-0.146556 
2.638007 
155 
-2.418173 
0.644846 
2.550073 
154 
-2.066439 
-1.055203 
2. 72594 
62 
-1.568148 
-0.23449 
1.494871 
61 
-2.169028 
-0.820713 
1.406937 
60 
-1.025892 
-1.846605 
2.110405 
59 
-1.875916 
-0.99658 
2.813874 
58 
-2.037127 
-1.289692 
2.813874 
Table 1. Attitude data from IMU in terrestrial photogrammetry 
coordinates system 
X = 
f f a A T f a A v ‘ 
A 
\ A 2J 
\Aj 
f A 
A 
\Aj 
( T \ 
j 
(4) 
= (a t a + a t + 
and so on. Thus the deviation angle error 
{(X x , OL y , Ot z ) between IMU coordinate system and camera 
coordinate system can be obtained. 
We can use this group of error through formula (2) to correct 
the IMU attitude data which have been transformed in the 
terrestrial photogrammetry coordinates system, in order to 
acquire the higher precision exterior orientation elements of the 
UAV images. Thus we complete correcting the original attitude 
data obtained from the UAV airborne GPS/INS inertial 
navigation system. 
3. RESULT ANALYSIS OF EXPERIMENTAL DATA 
A set of UAV aerial remote sensing images, which are shot on 
August, 2005 in Anshun, Guizhou province, are tested in this 
paper. Main performance indexes of the UAV remote sensing 
system adopted in this shooting are as follows. Operation height: 
1.5km; endurance velocity: 170km/h; maximum endurance time: 
30h; navigation accuracy: 50m; effective load: 60kg etc. This 
UAV remote sensing platform is composed of three sub- 
modules: UAV platform; camera subsystem; aerial remote 
sensing control subsystem. Among them, UAV platform is 
responsible for flight mission; camera subsystem is responsible 
for exposure and storage of original data of images; and aerial 
remote sensing control subsystem is responsible for controlling 
camera’s trigger and the data transmission between camera 
system and UAV platform. The images in this flight experiment 
are shot according to time, and the shooting interval t=5s; focal 
length f=83.112mm. Table 1 lists out partial results of original 
attitude data in terrestrial photogrammetry coordinates system 
for IMU. 
resection as true value, we make whole adjustment on the data, 
and the result is 
(a x ,a y ,a z ) = (-0.2464 °,-0.5959 °,0.4927°) .The 
n the attitude data of the images shot in this flight experiment 
are corrected using this error. Table 2 lists out partial 
calibration results and the results calculated through resection. 
After that we can compare these calibration results and the 
original attitude data with the results computed by resection. 
Figure 3, Figure 4 and Figure 5 list out the comparative results. 
Image 
Number 
Corrected Results Computed by 
Deviation Angle Errors 
Results Computed by 
Resection(True Value) 
Phi/deg 
Omega/deg 
Kappa/deg 
Phi/deg 
Omega/deg 
Rapp a/deg 
158 
-2.1944 
-0.7105 
3.306 
-2.6632 
-0.757 
3.7558 
157 
-2.1658 
0.1556 
3.3976 
-3.8457 
0.1343 
3.8388 
156 
-2 6528 
-0.4183 
3.1283 
-2.7834 
-0.4375 
3.7432 
155 
-3.0023 
0.3724 
3.3174 
-2.7665 
0.3924 
3.1443 
154 
-2.6528 
-1.3293 
3.2086 
-2.0373 
-0.9258 
3.1881 
62 
-2.1601 
-0.4927 
1.9882 
-2 0578 
-0.4544 
1.8221 
61 
-2.7617 
-1.0772 
1.8908 
-2.6543 
-1.0235 
1.7332 
60 
-1.6157 
-2.1142 
2.584 
-1.3873 
-1.9719 
2.6542 
59 
-2.458 
-1.272 
3.3002 
-2.3911 
-1.1574 
3 5212 
58 
-2.6241 
-1.5642 
3.2945 
-2 5476 
-1 4427 
3.1458 
Table 2. The corrected attitude data and the results 
calculated by resection 
158 15? 156 155 1 54 62 61 60 59 58 
—♦—Original data fro* IIU 
in Terrestrial 
Photogrammetry 
Coordinate System - 
The results calculated 
through resection 
-»—Corrected results 
computed through 
deviation angle error - 
The results calculated 
through resection 
Figure 3. The comparative results of Phi between the original 
attitude data and the corrected attitude data 
According to the deviation angle error correction method 
proposed in this paper, regarding the results computed by 
1245