I know this question may seem repetitive but I am not able find a solution hence I am asking this question . 1)I have downloaded OSDM data, SRTM SWBD data and also the corresponding .HGT file containing altitude for Sachsen Germany and successfully imported all the data both vector or raster into a postgis database. 2)I want to combine the Planet_osm_line data along with the swbd data and .hgt data to form a single database which consists of latitude, longitude and altitude and then visualise this using a geoserver. 3) With the help of SQL queries I have found the geometry of all these three data types as planet_osm_line is linestring(xy,xy) , SWBD data is multipolygon(x,y,z,m) and hgt data is polygon(xy,xy) 4) I am not able find the altitude value which is given as raster data for each longitude and latitude points, the altitude file .hgt originally has only 1 row and 3 columns like rid, rast and file name and when transformed using ASTEXT it gives the geometry as polygon(xy,xy) the file name is N50E013.hgt.

What is the correlation between lat/lon and altitude? How to find the altitude for each lat/lon value?

The data of the first rows of each of the datatypes are as follows SWBD data :- "MULTIPOLYGON ZM (((12.5719444444444 50.9923611111111 191 0,12.5719444444444 50.9926388888889 191 0,12.5741666666667 50.9926388888889 191 0).

planet_osm_line :- "LINESTRING(13.7424219061054 51.0133491016638,13.7429582886724 51.0134227613141,13.7439974414817 51.0133856445798,13.7448337999365 51.0134121637281,13.7453285287494)

.HGT file "POLYGON((12.9995833333333 51.0004166666667,14.0004166666667 51.0004166666667,14.0004166666667 49.9995833333333,12.9995833333333 49.9995833333333,12.9995833333333 51.0004166666667))"

Can anybody guide me?

  • I need to extract elevation or altitude in meters from the .hgt file which orginally has three tables rid,rast and filename , I have read all the related documents to the .hgt file but only able to understand that it is a 2 byte binary signed integer with wgs84/ems96 reference and geography projection (lat/lon) and when transformed using astext it gives the polygon format mentioned above like(X Y ,X Y) , all the mathematics should be in terms if sphere as its geography projection, Does any body know how to get elevation in meters for each corresponding lat/lon values. – darshan Mar 11 '16 at 12:11
  • SWBD data (e013n51e.zip) :- dds.cr.usgs.gov/srtm/version2_1/SWBD/SWBDeast corresponding hgt file N51E013.hgt.zip :- dds.cr.usgs.gov/srtm/version2_1/SRTM3/Eurasia – darshan Mar 11 '16 at 13:02
  • guys any suggestions – darshan Mar 29 '16 at 11:49

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