Re: [Qgis-user] Model for Temporal Measurement (vector) Datasets ?

[Anita Graser via Qgis-user]

Hi Richard,

On 02.09.2022 13:07, Richard Duivenvoorde wrote:

Anybody is aware of a model in which data owns a location, but THAT
location has a (growing) set of [timestamp, value] observation data to
it


MobilityDB has temporal temporal bools, ints, floats, texts, and
geometries: https://docs.mobilitydb.com/MobilityDB/develop/ch03.html

So that would cover the storage question but the visualization issue
remains until we implement support for these types in Temporal Controller.

Regards,

Anita


___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

Re: [Qgis-user] Model for Temporal Measurement (vector) Datasets ?

[chris hermansen via Qgis-user]

Richard and list,

On Fri, Sep 2, 2022 at 4:07 AM Richard Duivenvoorde via Qgis-user <
qgis-user@lists.osgeo.org> wrote:

> Hi All,
>
> Anybody is aware of a model in which data owns a location, but THAT
> location has a (growing) set of [timestamp, value] observation data to
> it
>
> We've done this but clumsily by duplicating the spatial data, one for each
point (ie a one-to-many join).

Also with start-datetime and end-datetime which is even uglier - the
overlap of datetime of occurrence vs datetime of display is really ugly,
especially when you're trying to visually display "point of ignition",
"bloom", "fading away" if you get my meaning.  A sort of heat map but
automated.

Anyway, as may be obvious from the above I'm also very interested.  Years
ago in the IJGIS there was an article about design of spatial databases
with time measures, but sad to say all my IJGIS issues have long since been
recycled.

Maybe someone is doing this in d3.js?  Seems like a logical framework for
this sort of thing...


-- 
Chris Hermansen · clhermansen "at" gmail "dot" com

C'est ma façon de parler.
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user

[Qgis-user] Model for Temporal Measurement (vector) Datasets ?

[Richard Duivenvoorde via Qgis-user]

Hi All,

Anybody is aware of a model in which data owns a location, but THAT location 
has a (growing) set of [timestamp, value] observation data to it

In GIS/QGIS everything is tabular (talking about vector here, I know meshes can 
have more shapes).

But in the IOT world the 'location' is 'just an attribute', and the 'other' 
data is actually more of interest (and growing in time).

Currently to view measurements, 'we' often replicate the location for every 
value/measurement: we create a 'Feature' for every time step (eg for example 
via a WFS)

The OGC has a SensorThingsApi (STA) standard, in which for given location you 
can request all values/observations (of filter a certain sensortype/parameter). 
So one geometry has a full table of data to it.

BUT to 'work' with that data in QGIS, you always have to 'flatten' it, one way 
or another, (I think), for every time step: create a feature with: location, 
time, value...

My Question:

- isn't there some model (or can we come up with one) in which a location can 
actually have a range of time/value data (like some table join like), and when 
you use the Temporal Controller, you style your layer by RE-using the one 
location, but getting the value for current Timestamp (in the TimeController). 
Some sort of indirect filtering?

- or is this the mesh model (I know netcdf's in which you have often predefined 
meshes/location and the data/time vector is growing)?
And would a solution be to have some kind of in memory vector -> mesh loader or 
so???

I hope this makes sense to others. Any input appreciated.

Regards,

Richard Duivenvoorde

PS, if you want to play with SensorThingsApi:
- install: https://github.com/AirBreak-UIA/SensorThingsAPI_QGIS-plugin
- connect it to: 
https://airquality-frost.k8s.ilt-dmz.iosb.fraunhofer.de/v1.1/Locations
(around 5000 location and 500-million 'observations')
- load all locations in one layer, and click on a location
My point: the data is then viewable/selectable by table and graph, but NOT 
loadable in a sense way (yet) in QGIS...
___
Qgis-user mailing list
Qgis-user@lists.osgeo.org
List info: https://lists.osgeo.org/mailman/listinfo/qgis-user
Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user