Smartphone's GPS-Koordinaten korrigieren.
Verfasst: 04.04.2012 - 23:16
Liebe Experten,
ich befasse mich gerade mit den Möglichkeiten eines Smartphones in der Anwendung für Sehbehinderte Menschen. Sie nutzen GPS-Systeme heute schon als Navigation. Eine Hinderniserkennung findet jedoch mit anderen Mitteln statt (Langstock, Ultraschall).
Um einen Hinderniserkennung für Sehbehinderte Menschen mittels GPS und einem Smartphone zu ermöglichen ist eine höhere Positionsgenauigkeit (Submeter-Bereich) notwendig.
Eine erste Recherche entwickelte folgende Ideen:
A) Die Smartphone-GPS Koordinaten mittel RTK-Daten korrigieren (Ich nutze das Samsung Galaxy Note mit hochmodernem A-GPS/Glonass-Baustein)
B) u-Blox EVK-6T in Verbindung mit dem Smartphone
Hat jemand eine Idee/ Erfahrungen über die Machbarkeit?
Gerade zu A) gibt es nicht öffentlich zugänglichen Master Thesis http://theses.lib.polyu.edu.hk/handle/200/3615
...Experiments are also designed and carried out for verifying the effect of corrections data applied for improving the positioning accuracy of GPS mobile phone. Single point positioning of GPS mobile phone tells users latitude, longitude and altitude. At the same time RTCM DGPS data are obtained via Ntrip service. After decoding, pseudo-range correction could be acquired. Pseudo-range difference can not be applied directly here because currently most existing mobile phones embedded with GPS chips can not output raw pseudo-range measurement. But positional difference is applicable here. That is through a series of mathematical operations, pseudo-range corrections can be converted to coordinates' corrections multiplied by the direction cosines of the unit vector pointing from the approximate user position to each satellite. Finally approximate positions are subtracted by coordinates' corrections directly and a new pair of coordinates is obtained for every point. Practically, for better precision, this computation is iterative until a satisfying accuracy appears. That is, the newly obtained coordinates should be taken as the approximate position again, and the all computations should be based on this new positional value, including the distance between satellites and users. Experiments result shows that the opinion and working flow are feasible. And the calculation results reveal that the improvement of positional difference applied in mobile phone positioning is obvious.
Vielen Dank.
Stefan
ich befasse mich gerade mit den Möglichkeiten eines Smartphones in der Anwendung für Sehbehinderte Menschen. Sie nutzen GPS-Systeme heute schon als Navigation. Eine Hinderniserkennung findet jedoch mit anderen Mitteln statt (Langstock, Ultraschall).
Um einen Hinderniserkennung für Sehbehinderte Menschen mittels GPS und einem Smartphone zu ermöglichen ist eine höhere Positionsgenauigkeit (Submeter-Bereich) notwendig.
Eine erste Recherche entwickelte folgende Ideen:
A) Die Smartphone-GPS Koordinaten mittel RTK-Daten korrigieren (Ich nutze das Samsung Galaxy Note mit hochmodernem A-GPS/Glonass-Baustein)
B) u-Blox EVK-6T in Verbindung mit dem Smartphone
Hat jemand eine Idee/ Erfahrungen über die Machbarkeit?
Gerade zu A) gibt es nicht öffentlich zugänglichen Master Thesis http://theses.lib.polyu.edu.hk/handle/200/3615
...Experiments are also designed and carried out for verifying the effect of corrections data applied for improving the positioning accuracy of GPS mobile phone. Single point positioning of GPS mobile phone tells users latitude, longitude and altitude. At the same time RTCM DGPS data are obtained via Ntrip service. After decoding, pseudo-range correction could be acquired. Pseudo-range difference can not be applied directly here because currently most existing mobile phones embedded with GPS chips can not output raw pseudo-range measurement. But positional difference is applicable here. That is through a series of mathematical operations, pseudo-range corrections can be converted to coordinates' corrections multiplied by the direction cosines of the unit vector pointing from the approximate user position to each satellite. Finally approximate positions are subtracted by coordinates' corrections directly and a new pair of coordinates is obtained for every point. Practically, for better precision, this computation is iterative until a satisfying accuracy appears. That is, the newly obtained coordinates should be taken as the approximate position again, and the all computations should be based on this new positional value, including the distance between satellites and users. Experiments result shows that the opinion and working flow are feasible. And the calculation results reveal that the improvement of positional difference applied in mobile phone positioning is obvious.
Vielen Dank.
Stefan