[Qgis-user] qgis and gps in real-time

[Chris H]

On Friday 07 March 2008 05:17:23 am Luca Casagrande wrote:

> Hello Andrea.
>
> I hope not be OT, but here [1] you can find an application similar to the
> one you are going to start.
> In that example, the tracking system is made with a Web Application but it
> can be expanded via Qgis, for the
> reason that the most import thing is to update the data from the receiver.
> Once you have the data updated at a certain interval, you can access them
> with anything (for examples a Qgis plugin that
> will reload data at a selected interval).

I think this is not as simple as described. If realtime tracking is required 
and to be displayed, then several things need to be considered. The gps data 
will be sent as either NMEA 0183 or NMEA 2000 that is known as those are the 
only available outputs. Most likely NMEA 0183. Then the data needs to be 
captured by receiver. The data is typically in text format or pending on the 
model. See: http://www.gpsinformation.org/dale/nmea.htm

Then you need to consider what data of the data set is to be displayed as the 
NMEA output provides for a lot of options. Next you need to consider how the 
data is to be displayed and this is dependent on how many people and in what 
locations need to view the data at the same time. If its one person then a 
qgis solution "may" be possible but qgis from my vary basic review (new to al 
this is more or less a desktop gis solution: ie: making maps from various 
data source) but if more then one person is required to view the data then an 
integrated mapping solution such as presented in the article is the answer.  
Mapping servers are heavy weight server based solutions that allow for 
presentation of data and associated data layers which can be presented to a 
multitude of users via the net. Their function is to serve up maps created by 
application like qgis but they do support map and image creation on the fly 
pending on how you configure the puppy.  While this is the classic and heavy 
weight solution its probably the preferred one. I would explore both however 
before making a decision. 

Should you go the qgis route and develop a realtime gps data capture pluggin 
this would be interesting. I think, Im not sure on this that you would be 
limited in terms of viewing the balloon on the associated map to only the  
person running qgis. In not aware of qgis being available to multiple users at 
the same time unless you use a VNC solution which is essentially a screen 
scrape. 

-- 
/ch