3-2-9 
Eqs(5) anil Eqs(5.a) describes the positioning accuracy when flight direction is coincide with 
the X axis of the geographic coordinate system. If the flight direction angle (or azimuth) is AT° , the 
mean square errors in the direction of X, Y and Z axis can expressed as follow: 
1 
2? 
COS K° 
-sin a: 0 
o" 
Xv" 
My 
= 
sin/c° 
COS K° 
0 
My 
(6) 
My._ 
0 
0 , 
1 
M, 
To describe the errors propagation in Airborne Laser-Ranging & Multispectral-Imaging 
Mapping System and their influences to the positioning accuracy of the system, we have the 
simulating calculation for ALIMS. The accuracy parameters of each sensor in ALIMS are listed in 
Table 1 and Fig. 3 shown the results for different configurations of the system. The flight height for 
.simulating is GOOM. The swath angle for simulation is from is 90° (from nadir to one side of the strip 
is 0° to 45°) for whiskbrooin scanner and rotated from 0° to 3G0° for conic scanner. 
GPS(X,Y,Z) 
LRF 
Roll 
Pitch 
Heading 
Encoder 
1 
±0.10m 
±0.10m 
±30” 
±30” 
±45” 
±1.0’ 
2 
± 0.25m 
±0.25m 
±4,5” 
±45” 
±60” 
±2.5’ 
3 
± 0.50m 
±0.50m 
±60” 
±60” 
±90” 
±5.0’ 
Table 1. Parameters for Simulating 
Fig.3 Mean Square Error (m) in X, Y and Z Axes for Whiskbrooin Scanner