How about this for an approach? - Create a line from the start and end point using ST_MakeLine - Densify it using ST_Segmentize (e.g. to a1 km interval) - Extract the individual points using ST_DumpPoints - For each point, query to find the nearest elevation point
On Thu, Jan 6, 2022 at 12:51 PM Luca Bertoncello <lucab...@lucabert.de> wrote: > Hi list! > > I have a table in my PostGIS database, with the ground elevation of Europe. > The table is so: > > gis=# \d elevation > Tabelle »public.elevation« > Spalte | Typ | Sortierfolge | NULL erlaubt? | Vorgabewert > -----------+------------------+--------------+---------------+------------- > latlng | geography | | | > lat | double precision | | | > lng | double precision | | | > elevation | real | | | > > lat and lng are just used for an export to a SQLite-DB for use in an > App. The same data are in "latlng" as geography... > The table has currently a precision of 3x3 Km, but I can import data > with a better precision, too, of course. > > So my question... > I'd like to use these data to create a vertical profile similar to the > one I can get from Google-Maps. > Currently, with a simple query, I can get the elevation of a given point. > Of course, I don't have _all_ point in the table, so I have to search > the nearest point, but this is OK... > > What I need is a function that receive two coordinates as parameters. > These coordinates define a line from A to B. > I'd like to retrieve all elevations in this line, with a given interval, > so that I can retrieve for example the elevation every kilometer or so. > > And I don't have any idea how to do that... > > Can someone suggest me a way? > > Thanks a lot > Luca Bertoncello > (lucab...@lucabert.de) > _______________________________________________ > postgis-users mailing list > postgis-users@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/postgis-users >
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