This tutorial goes over how to process a single landsat image on a single machine, using GeoTrellis and spark. We will create a server that will serve out tiles onto a web map that represent an NDVI calculation on our image. The calculation of the NDVI and the rendering of the PNG tile will be dynamic and happen per tile request.

Download this landsat image: https://s3.amazonaws.com/geotrellis-sample-datasets/landsat/LC80140322014139LGN00.tar.bz

Un-tar this into data/landsat

The code in src/main/scala/tutorial/MaskRedAndNearInfrared.scala will do this.

> ./sbt run

Select the tutorial.MaskRedAndNearInfrared to run.

This will produce data/r-nir.tif

The code in src/main/scala/tutorial/CreateNDVIPng.scala will do this.

> ./sbt run

Select the tutorial.CreateNDVIPng to run.

This will produce data/ndvi.png

This step will ingest the multiband image we made a previous step into a indexed tile set that GeoTrellis can quickly read data out of. We'll ingest it as WebMercator tiles, where the tiles are cut according to the Slippy Map tile coordinate representation, at multiple zoom levels.

The code is in the src/main/scala/tutorial/IngestImage.scala file.

> ./sbt run

Select the tutorial.IngestImage to run.

Tiles will be generated in the data/catalog directory.

This step will start a server that will serve out NDVI images onto a web map.

The code is located in the src/main/scala/tutorial/ServeNDVI.scala file.

> ./sbt run

Select the tutorial.ServeNDVI to run.

You can now open static/index.html and see our NDVI tiles on a web map.