Why geographic data is not stored as WKT?

Hi!

I am learning about the whole KoBoToolbox. I think it’s awesome!

Although, I do not really understand the reason why geodata like point, area/Polygon or line/LineString are internally stored in that format, as a sequence of points like “latitude longitude elevation accuracy”, which I think it’s exclusively used by ODK and is not widely understood by other software.

I realized, for example, areas/polygons cannot be load directly in a leaflet map because of its ODK’s geoshape format. Instead it yields The map is not available because this form does not have a “geopoint” field.

I really believe it would be the best choice to store it in the database in a standard and well-known format, i.e. WKT, as PostgreSQL+PostGIS does. This would have many benefits, included some robust free opensource tools to manipulate easily, for exporting to KML, SHP, GeoJSON or to load it directly to a leaflet map layer.

I understand this must have its history, design and implementation decisions involved, may be this is inherited from previous projects… Anyway, this is just a suggestion.

Thanks!

1 Like

Hi @santipesta,

Thank you for providing us with your valuable suggestions. It seems interesting. Could you be kind enough to describe a bit more about WKT format (how it looks like, how the users should benefit from the same over the existing Lat/Long format and more).

Also kindly please be informed that KoBoToolbox supports exporting geopoint data as KML format. For details, you could also have a look at our support article Exporting and Downloading Your Data.

Have a great day!

Hi @Kal_Lam,
I strongly recommend using WKT instead of custom GPS coordinate listing. WKT, as the abbreviation suggests :slight_smile:, is a well-known text representation of geometry. you can find out more abput WKT here: https://en.wikipedia.org/wiki/Well-known_text_representation_of_geometry.
Key benefits of using WKT rather than (or in addition to) custom GPS coordinate lists:

  • WKT is an OGC (Open Geospatial Consortium) standard
  • WKT standard supports both single and multi-part geometries
  • it is implemented in most popular GIS open-source database - PostGIS (e.g. ST_AsText, or ST_GeomFromText - to convert geometry from/to WKT)
  • it is supported by the most popular open source desktop GIS software (QGIS): e.g. you can import CSV file with a WKT geometry column directly as a shapefile (point / polygon) - see below screenshot:

Let me know if you’d need more info on WKT and other potential GIS use cases for KoBo.

1 Like