From 6ec45a5dd679c28f20666c65f15a88c376b73be1 Mon Sep 17 00:00:00 2001 From: Sam Date: Wed, 14 Aug 2024 11:47:45 +0100 Subject: [PATCH] Modify content --- content/blog/batch-import-postgis-rasters.md | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/content/blog/batch-import-postgis-rasters.md b/content/blog/batch-import-postgis-rasters.md index 212f5ba..167d1dd 100644 --- a/content/blog/batch-import-postgis-rasters.md +++ b/content/blog/batch-import-postgis-rasters.md @@ -51,7 +51,7 @@ Next we can run the following command to download the rasters. This will take so aws s3 cp s3://raster/SRTM_GL1/ . --recursive --endpoint-url https://opentopography.s3.sdsc.edu --no-sign-request {{}} -If you'd prefer to download specific rasters or rasters for a region instead, you can checkout this [website](https://dwtkns.com/srtm30m/). +If you'd prefer to download specific rasters or rasters for a region instead of downloading them all, you can select regions for download from the OpenTopography [website](https://portal.opentopography.org/raster?opentopoID=OTSRTM.082015.4326.1) using the interactive map. ## Using raster2pgsql to import raster tiles into PostGIS Now we have the data downloaded on our system, we can import it into our database. @@ -98,9 +98,9 @@ So we have just over 12 million 128x128 tiles in the database. ## Raster Clipping -Now we have global SRTM data loaded in our local database, we can extract any of the tiles for further analysis and access this using any application. +Now we have global SRTM data loaded in our local database, we can extract the tiles we want for further analysis. -Here I'll demonstrate using the following PostGIS commands: `st_clip`, `st_intersects` and `st_union` to create a digital elevation table for singapore and access this from from within QGIS. +Here we'll create a digital elevation raster for Singapore to demonstrate using the following PostGIS commands: `st_clip`, `st_intersects` and `st_union`, then import this into QGIS to style and visualise the results. I already have countries vector data in my Postgres database that I extracted from OpenStreetMaps. You can download a pg_dump of this [here](/data/countries.sql) to insert into your database. Alternatively, I have a post [here](/blogs/import-osm-countries-data) that explains the process to do this manually.