Geospatial dataset picker via fast Api Rest interface written in NodeJs for GDAL bindings and Fastify

• Online Demo Map

• Swagger API

• Article about this project

It is basically an advanced elevation service and Geopicker has been specially designed to offer the widest range of formats and methods of data requests that is possible, to adapt to any context of use by the client. Each endpoint and the parameters it accepts have been designed on the basis of the functioning of already existing services, gathering a complete and coherent collection of APIs. At present the index.html page contains a large implementation of browser side requests using LeafletJs as basemap and jQuery.

• Large Rest API: many endpoints suitable for each data request context
• JSON Schema: validation of routes and parameters, can be deactivated
• Customization: friendly configs and to help devs in many deploy contexts
• Formats: support for different geospatial input and output formatss

and includes some other additional functions:

• Densify: add more points in a sequence of coordinates, this improves the display on an elevation graph, adding intermediate positions at a minimum fixed distance.
• Simplify: unlike densify it removes points that are too close together from a geometry.
• Height: add the vertical distance from the ground, if input has elevation add a fourth coordinate with this value.
• Metadata: get additional informations for a certain geometry, can be for example the direction of a path.

The API is work in progress. This basic structure can be extended starting from the environment variable PREFIX which by default /

Additional global Parameters:

✔️ Done ❌ TODO 🚧 Work in Progress

Running by official Docker image:

docker run -v "/$(pwd)/tests/data:/data" -e DEMO_PAGE=true -p 8080:8080 stefcud/geopicker

Running from source code in development mode, requirements: nodejs 16.x > and glibc 2.28 (Ubuntu 20.x > ):

npm install
cd server && npm install && cd -
npm run dev

Browse the demo page: http://localhost:9090/

Full configuration options can be found in docs config

some useful tools for contributors npm run <scriptname>

• docker-up run in local docker-compose container
• start run in production mode
• bench run benchmarks
• dev run in development mode

Get single location exchanging a few bytes:

        $ curl "http://localhost:9090/elevation/11.123/46.123"

[195]

Post a json object and receive the same decorated with the result(still works with longitude,latitude):

$ curl -X POST -H 'Content-Type: application/json' \
  -d '{"lon": 11.123, "lat": 46.123"}' \
  "http://localhost:9090/elevation/lonlat"

{"lon": 11.123,"lat": 46.123,"val":195}

Get many stringified locations in one time(designed for not too long LineString):

curl "http://localhost:9090/elevation/11.1,46.1|11.2,46.2|11.3,46.3"

[195,1149,1051]

Post a very long LineString saving bytes:

$ curl -X POST -H 'Content-Type: application/json' \
  -d '[[10.9998,46.0064],[10.9998,46.0065],[10.9999,46.0066],[11.0000,46.0067]]' \
  "http://localhost:9090/elevation/locations"

[[10.9998,46.0064,900],[10.9998,46.0065,898],[10.9999,46.0066,898],[11.0000,46.0067,900]]

Post anyone GeoJSON geometry, the same input geometry is always returned which has a third dimension:

$ curl -X POST -H 'Content-Type: application/json' \
  -d '{"type":"LineString","coordinates":[[11.1,46.1],[11.2,46.2],[11.3,46.3]]}' \
  "http://localhost:9090/elevation/geometry"

{"type":"LineString","coordinates":[[11.1,46.1,195],[11.2,46.2,1149],[11.3,46.3,1051]]}

From version v1.6.1 /elevation/... is the same of /datasets/elevation/... datasets can be implicit.

benchmarks scripts: tests/benchmarks.js using AutoCannon

cd tests && npm install && cd -
npm run bench

The results testing a dataset of 2x2km geotiff

┌─────────┬──────┬──────┬───────┬──────┬─────────┬─────────┬──────┐
│ Stat    │ 2.5% │ 50%  │ 97.5% │ 99%  │ Avg     │ Stdev   │ Max  │
├─────────┼──────┼──────┼───────┼──────┼─────────┼─────────┼──────┤
│ Latency │ 0 ms │ 0 ms │ 0 ms  │ 1 ms │ 0.02 ms │ 0.16 ms │ 6 ms │
└─────────┴──────┴──────┴───────┴──────┴─────────┴─────────┴──────┘
┌───────────┬─────────┬─────────┬─────────┬─────────┬──────────┬─────────┬─────────┐
│ Stat      │ 1%      │ 2.5%    │ 50%     │ 97.5%   │ Avg      │ Stdev   │ Min     │
├───────────┼─────────┼─────────┼─────────┼─────────┼──────────┼─────────┼─────────┤
│ Req/Sec   │ 18111   │ 18111   │ 22783   │ 23471   │ 22175.28 │ 1473.21 │ 18099   │
├───────────┼─────────┼─────────┼─────────┼─────────┼──────────┼─────────┼─────────┤
│ Bytes/Sec │ 4.02 MB │ 4.02 MB │ 5.05 MB │ 5.21 MB │ 4.92 MB  │ 327 kB  │ 4.01 MB │
└───────────┴─────────┴─────────┴─────────┴─────────┴──────────┴─────────┴─────────┘

Req/Bytes counts sampled once per second.
# of samples: 11

244k requests in 11.01s, 54.1 MB read

for details see the descriptions in the Roadmap issues

Created by Stefano Cudini @zakis Distributed under the BSD 2-Clause license.