The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B5. Beijing 2008 
907 
solid solution 
unavailable 
pseudo-range 
solution 
differential 
GPS solution 
solid RTK 
solution 
float RTK 
solution 
Total 
original point num 
and portion of total 
10, 0.5% 
741,39.9% 
362, 19.5% 
388, 20.9% 
357, 19.2% 
1858 
filter remained 
(Tx,Ty,Tz=5.0) 
0, 0% 
582, 39.7% 
289, 19.7% 
328, 22.4% 
268, 18.3% 
1467 
filter remained 
(Tx,Ty,Tz=7.0) 
0, 0% 
607, 39.6% 
295, 19.2% 
349, 22.8% 
281, 18.3% 
1532 
filter remained 
(Tx,Ty,Tz=10.0) 
0, 0% 
623, 39.3% 
308, 19.4% 
360, 22.7% 
296, 18.7% 
1587 
Tab.l Network RTK filtered result analysis 
In the automatic integration work of GPS and DR of mobile 
mapping, the integration result also shows that filtered result of 
network RTK can make better solution for mobile mapping’s 
positioning and posing work compared to the original data. 
Some complicated city area has even obvious improved 
solution, and the filtering work in the paper also help mobile 
mapping based on network RTK meet the requirement of 
1:2000 scale mapping better than the original network RTK 
data. 
5. CONCLUSION AND PROSPECTS 
This paper discussed how to improve the reliability of network 
RTK in dynamic direct georeferencing positioning of land- 
based mobile mapping. Based on the dynamic characteristic of 
Doppler and DGPS 3D speed of the mobile platform, we 
filtered error data in sequential network RTK data. The 
experiment is performed based on the mobile mapping’s 
positioning data of Shanghai Yan’an Road, one of the most 
typical circumstances in metropolis. The analysis shows that 
network RTK can be used for mobile mapping in metropolis, 
and filtering method presented in the paper can filter crude part 
in network RTK data and thus improve the network RTK 
reliability and accuracy for city mobile mapping. 
Land-based mobile mapping has much more potential and 
revolutionary impetus in improving city’s development and 
management of infrastructure, utility, facility, emergency 
response, public security and so on. That calls for better 
development of mobile mapping itself. Network RTK is built in 
more and more big cities, and it has very distinguished 
economic and performance advantages compared to the 
traditional GPS. The next step of our work is to interpolate 
good points in sequential position data instead of the current 
filtering in dynamic network RTK application. In that issue, 
we’ll use high accuracy characteristics provided by differential 
Doppler measurement. 
ACKNOWLEDGEMENTS 
The paper is substantially supported by National 863 High-tech 
Project “Complicated Features’ Extraction and Analysis from 
Central Districts in Metropolis”, ChangJiang Scholars Program, 
Ministry of Education, PRC and Tongji University “985” 
Project Sub-system “Integrated Monitoring for City Spatial 
Information”. The author would like to thank ChangJiang 
Scholars Dr. Ron., Li and Dr. Hongxing Sun for their 
substantial help. 
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