2012
; wall
land
wall
iling
International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B4, 2012
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia
2.3 Results
Partial experimental results are as follows. Figure 10 presents
one of the results from our outdoor experiment for evaluation of
the availability when GNSS receivers including GPS,
GLONASS and QZSS are integrated in dense urban areas.
Figure 11 shows a result from pedestrian tracking taken from
laser scanner data in our indoor experiment. This result was
used as a reference value for evaluating the performance of
positioning sensors. The accuracy, integrity and continuity of
each sensor in our experimental environment are summarized in
Table 2 (although we recognize that the performance of sensor
system depends on an environment).
$77 Ww s aC n Glass wall
eo} Ls A Ck ; RS
Pedestrian trajectory i :
]
are dé eene ai ont
i ^
4»
200 vue
a "7 . es y
rc er ih ntl ete en oi Metal and
glass wall
-200 i i à i i j
0 Son 1000 2 1500 2000 2500
Kami
Figure 11. Result from pedestrian tracking using laser scanner
data
Table 2. Accuracy, integrity and continuity of each sensor in
the experimental environment
IMES | Light tag | RFID tag
Accuracy
1 ; :
(Service area) on 1.5m on
Static | 74.67 % | 26.38 % -
Move | 83.96 % | 97.70 % -
Continuity
Static | 94.49 % | 57.30 % | 100.00 %
Move | 54.15 % | 51.46 % | 79.75 %
Integrity
3. DISCUSSION
The first experiment involved a coarse-resolution indoor
navigation using position data taken at 22 points to investigate
availability and continuity in an indoor navigation environment.
The second experiment involved a fine-resolution indoor
navigation using position data taken at 254 points with electric
field maps generated from each sensor to investigate accuracy
and continuity in an indoor navigation environment. The third
experiment integrated navigation of both indoor and outdoor
environments to investigate availability and continuity in an
indoor-outdoor navigation environment. The fourth experiment
involved outdoor navigation using multiple satellite systems to
investigate accuracy, availability and integrity.
Based on the results from our experiments, we can make some
observations about seamless navigation using multiple
navigation systems, focusing on the following representative
issues from our research. The first issue is the improvement of
availability using multiple navigation systems. We have
clarified that outdoor positioning of multiple navigation
satellites has the potential to improve availability in an open-
sky environment. Indeed, compared with the use of GPS only,
the use of multiple navigation satellites improved the position
fix rate by 2096. On the other hand, we also clarified that in a
dense urban environment, the integrity of navigation decreases
from 100% to approximately 5096 because of multipath
interference. In addition, we clarified in our experiment that the
position fix rate decreases when the number of navigation
satellites increases.
The second issue is interference between indoor navigation
systems. We found that, because of interference, fewer satellite
signals are received by high-sensitivity GPS receivers when an
IMES transmitter is located within a 3 m radius of the receiver.
Therefore, we conclude that the design of IMES transmitter
arrangements should accommodate this restriction in indoor-
outdoor border areas for seamless navigation using GPS and
IMES.
The third issue is interference between the indoor navigation
and 3D measurement systems. When the orientation of time-of-
flight infrared camera is within 40? of the line of sight between
a lighting tag and a lighting tag receiver, infrared interference
renders the lighting tag system unavailable. Therefore, for
human sensing and autonomous robot navigation, we must
focus on the directional properties of sensors.
4. SUMMARY
The initial focus in our research was the construction of a test
environment for indoor-outdoor seamless navigation
experiments. Based on SARPs, we focused on accuracy,
availability, continuity and integrity to verify the effects of
seamless navigation under a combination of as many systems
and sensors as possible. We then conducted data acquisition and
data analysis in seamless navigation through four integrated
experiments. Based on the results of our experiments, we
summarized.some observations about seamless navigation using
multiple navigation systems.
References
[1] Dinesh Manandhar, Seiya Kawaguchi, Masayuki Uchida, Makoto
Ishii, Hideyuki Torimoto. 2008. IMES for Mobile Users Social
Implementation and Experiments based on Existing Cellular Phones for
Seamless Positioning. In: Proceedings of International Symposium 2008
on GPS-GNSS.
[2] S. Kogure, M. Sawabe, and M. Kishimoto. 2006. Status of QZSS
Navigation System in Japan. In: Proceedings of ION GNSS 2006, pp.
2092-2102.
Acknowledgements
This work forms part of a series of experiments conducted by a
committee in the Institute of Electrical Engineers of Japan
(IEEJ). This work is partly supported by the Strategic
Information and Communications R&D Promotion Programme
(SCOPE) of the Ministry of Internal Affairs and
Communications, Japan.
35
