Monday, 12 October 2015

Opening a Map on the GRASS GIS command line (Ubuntu Users)

With some quick keying in skills (unlike mine) you can open GRASS GIS, set the region of interest, display a map with an ordnance survey grid change the colour table of the map and add a scalebar and legend. Why not try it yourself with one of your maps and substitute 'mosaic' with your own map name.
  1. Open a terminal (Ctrl+Alt+T)
  2. Type 'grass70'
  3. Grass GIS will open
  4. Type:-
g.region rast=mosaic -p;d.mon wx0;d.rast mosaic;d.grid size=10000;r.colors mosaic col=gyr;d.redraw;d.barscale at=5,90;d.legend mosaic at=70,15,5,10

#then press 'return' key#

Remember when one process follows after another MMP; - Module Map Parameter;Module Map Parameter;Module Map Parameter;


Monday, 5 October 2015

QGIS User Group (Wales) 6th October 2015

It's a pleasure to be asked to speak at this event. Who would have thought that Wales (UK) would be one of the first areas to acknowledge there are perfectly good (and free) alternatives to the big player. Finally, the message is out there. Lets hope it's an even bigger event in 2016.

Processing Landsat 8 Multi-Spectral Images with Grass Tools & the potential of the 'QGIS-GRASS-PLUGIN'

Friday, 10 July 2015

Install GeoServer on Ubuntu 15.04 (localhost)

It's quite easy to find installation instructions for most Ubuntu versions but it's nice to check they still apply to the most recent release (15.04 at the time writing). I tested this yesterday and it still works for me. My thanks to Hongru Hou (link at the end of the article for full details).

Install Apache2 (if not installed):-
sudo apt-get install apache2  

sudo apt-get update

Test Apache2 web server is working:-

sudo /etc/init.d/apache2 start
sudo /etc/init.d/apache2 stop
sudo /etc/init.d/apache2 restart

Install Java 7 using the 'Webupd8team' repository:-

sudo add-apt-repository ppa:webupd8team/java


sudo apt-get install oracle-java7-installer

(takes about 10 minutes to download)

Install Tomcat7 (because it is GeoServer Web archive this replaces the missing Java Servlet of this edition)
sudo apt-get install tomcat7

then in order for tomcat7 to find JDK we need to open and amend one line:-

sudo vi /etc/default/tomcat7 


restart tomcat7:-

sudo /etc/init.d/tomcat7 restart

Download GeoServer 2.4.0 archive from:-

Extract the .war file somewhere convenient then:-

gksudo nautilus  (password required)

and manually copy/paste the .war file into:-


then restart apache2 again:-

/etc/init.d/apache2 restart

Now you should get your GeoServer login page:-


with some nice demo data included to get you started.

My thanks to Hongru Hou for his original blog:-

Thursday, 9 July 2015

Landsat 8 getting data the easy way

My thanks to Gregor Maclennan on the PPGIS forum for this link. I've been using Earth Explorer for years but this is simple, clean and no nonsense.

Wednesday, 8 July 2015

European Space Agency - Sentinel-2A/2B and the Copernicus Programme


The Sentinel-2 mission comprises ‘twin polar-orbiting’ satellites in the same orbit phased at 180 degrees to each other. The purpose of the mission is to detect variabilities in land surface conditions with a high revisit of 10 days with one satellite (2A), (5 days with two constellation)(2B). The coverage limits are between latitudes 56 degrees south and 84 degrees north.

Sentinel-2 will sample 13 spectral bands including 4 bands at 10m spatial resolution, these are B2 (490nm), B3 (560nm), B4 (665nm) and B8 (842nm), 6 bands at 20m spatial resolution, these are B5 (705nm), B6 (740nm), B7 (783nm), B8a (865nm), B11 (1610nm), B12 (2190nm) and finally 3 bands at 60m spatial resolution, these are B1 (443nm), B9 (945nm) and B10 (1375nm). 

These twin satellites will provide continuity of SPOT and LANDSAT type images for applications which include Land Management, Agriculture, Forestry, Disaster Control, Humanitarian Relief Operations, Risk Mapping and Security Operations in support of the ‘Copernicus’ Programme.

The products are available to users in SENTINEL-SAFE format, including images in georeferenced GML/ JPEG2000 format, quality indicators (defective pixels mask) and auxiliary data (XML/GIPPs) and metadata (XML). Images are available between 3 and 24 hours after sensing via online access.

Where Sentinel-2 fits in with other missions

The narrow width of the spectral bands limit the influences of water vapour which heavily contaminated the Landsat (NIR) band (760-900nm) range not sensitive enough to soil iron oxide content.
I will hopefully get the chance to obtain some of the data for South Wales in the UK and experiment with the bands using Grass 7. I will provide further feedback and a tutorial.

More importantly the data is free and the supporting software included is Open Source.
More information is available:-