tag: gis

Traffic Intensity

Running some traffic data through QGIS and outputting the standard way with labels:

Slightly smarter labels from the toolboxes:


Then adding some basic gradient steps and turning it into something slightly more interesting. A basis for more work on the intermediate glow grading and a ramp key wouldn't go amiss.

intermediate glow



Once upon a time (actually more than once) I lived in the beautiful hamlet of Winterburn, North Yorkshire. I've just downloaded some UK Government lidar data of the area to see what it looks like.


Rural Planning

Planning brief - requirement for a combination of techniques after acquiring the relevant data and information: CAD rendering, image manipulation, geo-location and growth-stage visualization for vegetation type.




Satellite project to protect ecosystems

My old thesis Professor Heiko Balzer

Good to see there is progress with this satellite project to kick off a new satellite project that aims to monitor the world's forests in near real-time.



My GIS MSc Thesis - Abstract


Characterisation of native tropical rainforest covering the study site, the Bobiri Butterfly Sanctuary, Ghana, has been most successfully completed in this exercise by assigning the HH, HV and HH-HV polarizations of the ALOS-Palsar instrument respectively to computer monitor RGB channels.

SRTM tile selection in Google Earth

This method required that ground sourced allometric data, which had been recorded with a certain projection system, was combined with the Palsar polarimetric data. This in turn required intermediate steps to prepare the data for the GIS software to combine all the data sets, using another image source for projection referencing purposes. A number of resampling transformations were used, with the Nearest Neighbour analysis appearing to offer the best solution in this case.

image pair composite

Imagery was compared visually with the Globcover land use classes, more precisely using side-by-side referencing by running Cartographica and Gamma X-window together, and finally by incorporating all the data sets together within a GIS, and experimenting with layer orders and transparencies on data with common projection systems.

transparent Nearest Neighbour over Globcover

From this, it is clear that a directly imported data source from Gamma Palsar processing software, into GIS RGB channels would be the simplest and most reliable, would it were possible to read-in the location information in the accompanying .par files.

RGB composite of nearest neighbour

Because of the importance attached to ground sourced allometric data in the formation of any forest type mapping exercise, the ALOS-Palsar instrument is employed because of it’s L-band forest cover suitability and the availability of site imagery.

CC Polarization RGB assigned composite over Globcover (overview)

Having contact with scientists working within the Bobiri Butterfly Sanctuary willing to forward this important source of ground data, enables the exercise of characterising the Bobiri site in a variety of ways, but a consistent methodology is required to enable a transferrable model that will produce a consistent output.



Map Inspecting

As I mention in my Info section, I have long thought I''d like a Google Map section to geo-tag photographs to, in a similar manner to Flickr and Panoramio. I like the Flickr implementation, but the quality of mapping isn''t as good as Googles'. Well now it''s landed (example only - no valid API key).

From the map points there are commonly links to slideshows of photographs such as those presently run off Lightbox, or those on Flickr and Picasa. Although Flickr seems to be the popular one, Picasa has the advantage of being viewable on the iPhone as well and is very suitable for this purpose.

The new page is built on the Google AJAX API loader, the tutorials seem to use the old code, but they''re not too bad to follow and the new is backward compatible, so mashing the two together was OK.

Having been through the Google Concepts and examples, I found the best way of learning and getting the page to work, was the long established method of unashamedly picking-over other site''s code. Having enabled the debug menu in Safari a while ago, I've actually found myself using the Javascript console, a whole new language to me.

One thing I have noticed in this though, is that the webkit Inspect Element sometimes messes-up the code - the View Source gets it right, as does Opera''s Console.

Hopefully as the new page grows I will learn how to implement the zoom zones to reveal more specific map points within groups (trips) as the magnification (and requirement) grows.