The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B5. Beijing 2008 
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Figure 6. The instrument used for positioning the MEMS INS 
The complete convergence of results required about 10 
iterations of calculus. Figure 7 shows the convergence of the bx 
parameter; in figure 8, an enlargement of figure 7 is shown. 
The calibration results are shown in Table 1, where: 
bx, by, bz are the bias factors divided by the gravity 
acceleration g; 
sx, sy and sz are the scale factors; 
0yz, 0 Z x> 0zy are the misalignment angles in radians. 
In the first column are reported the parameters, while in the 
second column the relevant variances are shown. 
bx (g) 
0,012133 
7,807 e-07 
by (g) 
0,023295 
3,876 e-07 
bz (g) 
-0,03593 
4,380 e-07 
sx 
0,00775 
1,491 e-06 
sy 
0,008838 
6,123 e-07 
sz 
0,008041 
5,746 e-07 
0VZ (rad) 
-0,00086 
2,056 e-06 
0zx (rad) 
0,01142 
1,597 e-06 
0zv (rad) 
-0,00049 
2,554 e-06 
Table 1. Accelerometers bias, scale and disalignment factors 
(first column) and variances (second column) 
The sensors are differently influenced by temperature. The 
temperature difference among the three axes, is about 1-2 °C. 
Besides, about two minutes after the turn on are needed, to 
stabilize the temperature. This is shown in Figure 8. 
Variation of temperature after the turn on 
sample 
The parameter values are in some cases higher than the ones 
declared by the datasheet, also by taking into account the 
influence of temperature. 
Figure 8. Variation of temperature after the turn-on. 
5. CONCLUSION AND FUTURE WORKS 
The multi-position method has been used for the calibration of a 
MEMS INS. The method is very fast and efficient. The 
convergence of the results, in the accelerometers calibration 
case, is relatively rapid and the procedure is not expensive. 
With reference to the calibrated sensor (ADIS 16350), the 
results showed the strong influence of temperature. 
In the future, the implementation of a new modified multi 
calibration method, which theoretical formulation we set up, is 
foreseen. 
xbias convergence 
REFERENCES 
Chatfield A. B., 1997, Fundamentals of High Accuracy Inertial 
Navigation, American Institute of Aeronautics and Astronautics, 
Inc.). 
El-Sheimy N., 2006, ENGO 623 Lecture Notes: Inertial 
Techniques and INS/DGPS Integration, Department of 
Geomatics Engineering, The University of Calgary, Winter 
Godha, S., 2006. Performance Evaluation of Low Cost MEMS- 
Based IMU Integrated With GPS for Land Vehicle Navigation 
Application. 
Figure 8.Oscillation of bx parameter after the fith iteration