NDVI in GRASS GIS

May 26, 2024 | GRASS

“Hey you’ve been on a NDVI kick as of late!”. Technically I’ve been on a learning kick as of late. When I get burned out I tend to float back to the thing that gives me some comfort and that’s numbers and mapping etc.

This morning (being a Holiday weekend) I decided to tackle NDVI in GRASS. I don’t know if you’ve fired up GRASS lately but it’s different. Different in a good way.

One interface and not a series of menus. Processing tools on the right. Map layers on the left.

So – how do I get an NDVI map out of this? I have the USGS NAIP with it’s four bands. So lets use r.in.gdal to import my raster. That’s going to give me a 4 band import.

Once that’s done a lot of things get set like region and resolution. If you remember – (or at least as I remember) that was a manual process. So you end with with 4 bands displayed in the view. That’s boring. Lets skip to the chase and use i.vi.

Aaaaannnnnndd with a click of the run button it’s done. That is it. You also get the python from the tool.

i.vi --overwrite output=NDVI viname=ndvi red=m_3408418_se_16_060_20220110.1@PERMANENT nir=m_3408418_se_16_060_20220110.4@PERMANENT green=m_3408418_se_16_060_20220110.2@PERMANENT blue=m_3408418_se_16_060_20220110.3@PERMANENT

Here you go:

I know there’s more that I can do at this point and I probably will when I take another break and dig into some common problems and tackling it with a different toolset.

You may also like

Class, GRASS, and LAS – LIDAR in TN Part 3

Class, GRASS, and LAS – LIDAR in TN Part 3

Part 1 Part 2 And now for Part 3. So something exciting happened. If you've been keeping up with the TN GIS Data site you'll notice a lot more data has been released in uncomfortably HUGE zip files. I downloaded two counties worth and have been exploring the data. In...

GRASS 7.2 is out

GRASS 7.2 is out

....But Randy you're a month late announcing it. I know. I'm behind. I've become a GRASS fan for the awesome processing power behind this software. For those who have kept up with the blog you've seen me do random things with LIDAR. I've used it to process Landsat....

GRASS GIS Meetup – Raleigh NC November 5th 2016

  Interested in using GRASS GIS as a geospatial processing backend? Or for reproducible research with Python? Or as a surprisingly powerful desktop GIS? Then come to the November GRASS GIS Raleigh meetup which will be specifically focused on getting newcomers...