Sunday, 13 July 2014

Martian glaciers in Crater "Greg"

As mentioned by Hartmann et al., there are a number of glacier-like features in the Martian Crater "Greg".

I am studying Martian glaciers, based on the list published in Souness et al. 2012 for my MSc dissertation.

Here are a couple of graphics, showing the Souness glaciers in the Greg crater:

I have used Google Fusion tables to plot these and exported to a KML for use in Google Earth using the CTX camera mosaic as a backdrop. The centres are plotted as snowflakes, heads in blue and termini in yellow, with purple and green used for the channel sides at the midpoint.

Below, I have tried using RSGISlib on Mars, using a layerstack combining topography and imagery from Mars Express HRSC, using a colour palette to show a segmentation. I'm not yet convinced the segmentation is picking them out, but work continues...

Friday, 11 July 2014

Buntings from the RSPB website

From the RSPB website:


Male cirl bunting feeding on seeds

The buntings of Europe, Asia and Africa are related to American sparrows.
They are rather finch-like but have differently-structured bills, slightly flatter heads and longer bodies, and many have longer tails with white sides. Some are short-legged and heavy-bodied and strictly terrestrial, others are lighter and live more in trees and bushes. Most have simple, unmusical but distinctive songs.
Some are long-distance migrants and several European and Asian species have appeared in the UK as rare vagrants.

Cirl bunting

A charming relative of the yellowhammer that is at the limit of its European range in the UK. ... More...
Cirl bunting

Corn bunting

This nondescript lowland farmland bird is the
largest of the buntings and is most usually seen perched on a wire or
post. It is a stout, dumpy bird brown which flies off with a fluttering
flight and ... More...
Corn bunting

Pete bunting

Pete buntings are a migratory species, being found
alternately in the Aberystwyth area of mid-Wales and in New Zealand. With strong capabilities in Remote Sensing, it can distinguish land cover from a great distance. More...
Pete bunting

Lapland bunting

Slightly smaller than a reed bunting with a well
marked head pattern, chestnut nape and chestnut wing panel. Spends most
of its time on the ground and often seen in small flocks. Occasional
birds are... More...
Lapland bunting

Reed bunting

Sparrow-sized but slim and with a long, deeply
notched tail, the male has a black head, white collar and a drooping
moustache. Females and winter males have a streaked head. In flight the
tail looks b... More...
Reed bunting

Snow bunting

Snow buntings are large buntings, with striking
`snowy' plumages. Males in summer have all white heads and underparts
contrasting with a black mantle and wing tips. Females are a more
mottled above.... More...
Snow bunting


Males are unmistakeable with a bright yellow head
and underparts, brown back streaked with black, and chestnut rump. In
flight it shows white outer tail feathers. Often seen perched on top of a
hedge ... More...

Thursday, 10 July 2014

Cornish identity in the 2011 census - part 2

Here is a map showing people throughout Cornwall, England and Wales, who listed Cornish as their national identity:

These are random dots below 300m.

Here is a map of people expressing Welsh identity:
And English (reduced in number by a factor of 10):

Wednesday, 9 July 2014

Cornish identity in the 2011 census

Here is a dot map representing all people in Cornwall declaring Cornish national identity in the 2011 census, generated using random points clipping the census output areas to the OS OpenData buildings layer.

As a heatmap, classifying by powers of 2:

Tuesday, 8 July 2014

Speakers of the Welsh language according to 2011 census.

Much was written about a relatively small drop in the percentage of Welsh speakers in Wales as recorded by the 2011 census. I'm sure an astronomer wouldn't believe it was anything other than statistical noise if her data showed a 1% change from one survey to another....

Nevertheless, it is possible to visualise the data in a different way to the standard colorised maps you often see about these things.

One way is the restriction of the census output polygons to where buildings exist as the Datashine project did. However their website does not display statistics for Welsh language skills, since the detailed question was not asked to census respondents living outside Wales.

How about we use a QGIS plugin to give each Welsh speaker in Wales (or actually here, anyone claiming any skill in Welsh) a circular piece of land 50 metres wide, randomly located somewhere below 300 metres above sea level in his output census area polygon:

So here we have the opposite problem to the issues with the typical visualisations with colourised choropleth maps where large but sparsely populated areas dominate visually,namely that denser areas are oversaturated at this scale.

It is also possible to take this random dot distribution and make it into a heatmap (click on the image for a larger version):

I also downloaded the OS OpenData buildings layer for the relevent grid squares covering Wales, and produced another dots distribution (this took QGIS some time).

This produces the following dot maps, giving each Welsh speaker 50 metre and 20 metre diameter circles of land respectively: