Some nice clear satellite images of Cornwall with Landsat 8 and Sentinel 2

The launch of Sentinel 2A and 2B as part of the European Space Agency's Copernicus Program, has increased the frequency with which medium resolution satellite imagery in optical and near infrared is available.

Landsat 8 (and 7) are also still operating, which take a given frame every 16 days each.

Landsat 7 unfortunately has a scan line corrector fault that means there are stripes of missing data:

There was a particularly cloud free image of Cornwall on Landsat 8 on 27th March 2017, which I show below, displayed using tuiview.

On the left is a visible light band combination using bands 2, 3 and 4 which are broadband blue, green and red bands, and on the right I use band 7 (which is known as SWIR2, which stands for short-wave infrared 2, at around 2.2 micrometres wavelength), band 5 (near infrared), and band 4 (red, but shown as blue here). Infrared bands can be a bit confusing, especially if you have been exposed to both terrestrial remote sensing and astronomers terminology.

A somewhat closer view, with Truro at the top-right, showing Falmouth, the Fal estuary, Camborne and Redruth, and Stithians Reservoir in the centre.

Sentinel 2 has also captured some good clear images recently in the area, such as this. These are processed in the Sentinel 2 Toolbox within the Sentinel Application Platform, using sen2cor to process to Level 2A (surface reflectance)

This is from 18th April 2017, with a clear view of parts of Cornwall.

Sentinel 2 also took a mostly clear (apart from some high cloud) image on 27th March 2017:

The top image uses bands 2, 3 and 4 for the blue, green and red channels respectively, and the bottom uses 2, 8 (842nm) and 12 (2190nm).

Since the different bands are at different resolutions, when using the Sentinel Application Platform it is necessary to resample the output under the Raster menu, to process it further. This can produce a very large file, so I used the GeoTIFF / BigTIFF option because otherwise it would produce a file larger than a standard GeoTIFF file can be, when the 10m resolution is used. This can then be converted to a .KEA file for a smaller file size with gdal_translate.

The reason the file size is enormous is the output from resampling has 45 bands, because although it outputs only 10 data bands, that is 2, 3, 4, 5, 6,7 ,8 , 8a, 11 and 12, there are also atmosphere optical depth, water vapour, cloud probability, snow probability, and a scene classification, and then bands describing zenith angle, solar angle for every bands. As an uncompressed GeoTIFF this was 22 gigabytes for each tile, but is less than 1GB as a KEA (and I selected only the first 15 bands using rsgislib).

Four Sentinel 2 tiles combined (UUA, UUB, UVA, and UVB) to provide an overview of Cornwall and Devon - with border overplotted in QGIS - visible light

Using Band 12 = red, Band 8 = green and Band 2 = blue.

I have also opened them in QGIS and overplotted a map based on OpenStreetMap:

Sentinel 2 - 18th April 2017 - visible light

Sentinel 2 - 18th April 2017 - Band 12 (2.2 μm), Band 8 (842nm), and Band 2 (blue).

Landsat 8 - 27th March 2017 - Bands 4 3 and 2 (visible light)

Landsat 8 - 27th March 2017 - Bands 7, 5 and 2

Sentinel 2 - 26th March 2017 - visible light

Sentinel 2 - 26th March 2017 - Bands 12, 8, 2

Another possible band combination of the 18th April image, which is visible light but with the red and green channels swapped, and blue stretched a bit further to attempt to see the bluebells in the woodland shown from Sentinel2. The location is just to the right of the gridlines crossing at 183000, 41000

I will blog again about some of these when I have some time to experiment with processing. I have used the Sentinel 2 Toolbox and sen2cor to process the images, but I would also like to try ARCSI for processing from Level 1C to surface reflectance for Sentinel 2.

Cornwall and Devon, with the ESA Sentinel1B synthetic aperture radar satellite

The European Space Agency operates the pair of Sentinel 1 synthetic aperture radar satellites.

The advantage of radar is that it is not affected by clouds to the same degree that optical remote sensing is,  and there is also useful information gained by the polarisation.

As an example, I downloaded a Sentinel 1B product covering Cornwall and Devon which was taken on 7th October 2016, from the Copernicus data hub.

The type of product I used is the Interferometric Wide Swath mode (further detail).

I used the Sentinel Toolbox to perform orthorectification automatically, and visualise as a RGB with VH polarisation in the red channel, VV in the green, and the ratio between the two in the blue.

Truro

The stripmap mode of aquisition, which is less commonly used, provides a higher resolutionof 5m x 5m.

Here is an image from 11th December 2014, with the same colour scheme used.

Returning to the interferometric wide swath mode, overlaying roads and placenames for context. The colour scaling is slightly different in this image, making the green band less strong.

A portion from a Sentinel 2A image from 30th September 2016, using bands 11, 8 and 4 (1610nm, 842nm, 655nm).

The Level 2A product includes a basic pixel level land cover classification - there are some errors here note some cloud shadow has been classified as water or cloud, and spurious snow/ice around Porthtowan.

Atmospheric correction of Sentinel 2 images

I recently downloaded the Sentinel Application Platform including the Sentinel 2 Toolbox.

This looks to be a fairly fully featured image processing program, but what I was most interested in doing is the atmospheric correction for the Sentinel2 images I recently downloaded.

The Sentinel 2 'sen2cor' plugin accomplishes this, which wasn't too difficult to install, making use of anaconda to manage the various dependencies. Once I managed to get the environment variables set, and have it find all of the libraries it pretty much just worked.

After this, I tried using my own script for stacking the bands, which came out with a non-georeferenced image. I then noticed I could save the layerstacked image as a GeoTIFF/BigTIFF from within SNAP. A single 'granule' of Sentinel2 resampled to 10m produced a 9GB GeoTIFF, so I converted to KEA with gdal_translate.

Sentinel 2 image processed to Level2A, with SNAP and sen2cor. Bands B11/B8/B4

Zooming in on the Truro area. Penryn can be seen at the lower-left.

Using my rsgislib-landexplorer program to juxtapose geotagged ground-level images with Sentinel2

The same as above, but the non-atmosphere corrected version of the Sentinel2 image.

False colour composite of Sentinel 2 - 30.05.16

After using the script in the previous post to create a layerstacked .kea file for each "granule" within the Sentinel 2 images I downloaded, I created a false colour composite mapping band 11 (SWIR 1610nm) to red, band 8 (NIR, broadband centred around 842nm) to green, and band 4 (red 665nm) to blue.

See https://sentinel.esa.int/web/sentinel/user-guides/sentinel-2-msi/resolutions/spatial for a description of the bands available in Sentinel 2.

Here is a mosaic made in Tuiview:

After some issues with opening .kea files in QGIS (due to having reinstalled Ubuntu recently and needing to recompile KEAlib and then finding that due to being compiled against GDAL 2.1 libraries it didn't work in QGIS which was using GDAL 1.11),  I sorted this out, and have a QGIS project file showing the image. I also show some placenames from OpenStreetMap, and hill names from www.hill-bagging.co.uk for context.

Some screenshots of QGIS are shown below:

Aberystwyth area

Bodmin Moor, Cornwall. Road construction can be seen at the lower left.

Falmouth and surrounding area.

Snowdon

Truro area.

Plymouth, Saltash and Torpoint and the Rame peninsula

A clear day for Sentinel 2 satellite image of Cornwall

The ESA Copernicus programme includes the twin satellites Sentinel 2A and Sentinel 2B which have a multiband sensor. Details can be found here: https://sentinel.esa.int/web/sentinel/missions/sentinel-2.

Sentinel 2A has already been launched and is taking data, and Sentinel 2B will be launched later in 2016.

The Scientific Data Hub provides access to the data, although there is also access via an API, and via Amazon Web Services, and USGS Earth Explorer (currently some time behind).

Until recently, the images of Cornwall had been mostly heavily affected by cloud, although there was a better one taken on 30th May 2016.

A composite of bands 2, 3, and 4 (not atmospherically corrected) showing west Cornwall.

A composite of bands 2, 3 and 4 (not atmospherically corrected) around Aberystwyth in mid-Wales.

A Python script, using RSGISlib to stack Sentinel2 images into a band-stacked .kea file:

# David Trethewey 01-06-2016
#
# Sentinel2 Bands Stacker
# Uses visible, NIR, SWIR bands
# 
# Assumptions:
#
# the .jp2 files are in the current directory
# that this script is being run from
#
# there is only one Sentinel2 scene in the directory
# and no other jp2 files
#  
# Converts jp2 files of each band to single stacked file
#  
# imports
import rsgislib
import rsgislib.imageutils
import os.path
import sys

# image list
# find all *.jp2 files in the current directory
directory = os.getcwd()
dirFileList = os.listdir(directory)
# print dirFileList

jp2FileList = [f for f in dirFileList if (f[-4:].lower()=='.jp2')]

bands = ['01', '02', '03', '04', '05', '06', '07', '08', '09', '10', '11', '12', '8A']
# bands that are already at 10m resolution
bands_10m = ['02', '03', '04', '08']

# resample other bands to resolution of blue image (B02)
bands_toberesam = [b for b in bands if b not in bands_10m]

# identify the band number by counting backwards from the end in the filename
Bands_VIS_NIR_SWIR_FileList = [f for f in jp2FileList if (f[-6:-4] in bands)and(f[-7]=='B')]

# list of bands to be resampled
Bands_resam_FileList = [f for f in jp2FileList if (f[-6:-4] in bands_toberesam)and(f[-7]=='B')]

# find the filename of the blue image
blue_image = [f for f in jp2FileList if (f[-6:-4] == '02')and(f[-7]=='B')][0]

# bands to be resampled 20m --> 10m
# 05, 06, 07, 8b, 11, 12
# bands to be resampled 60m --> 10m
# 01, 09, 10

for b in Bands_resam_FileList:
    print("resampling band {q} to 10m".format(q=b[-6:-4]))
    outFile = b[:-4]+'_10m.kea'
    rsgislib.imageutils.resampleImage2Match(blue_image, b, outFile, 'KEA', 'cubic')
    Bands_VIS_NIR_SWIR_FileList.remove(b)
    Bands_VIS_NIR_SWIR_FileList.append(outFile)

Bands_VIS_NIR_SWIR_FileList = sorted(Bands_VIS_NIR_SWIR_FileList)

fileNameBase = blue_image[:-7]

# Sentinel2 bands
bandNamesList = ["B1Coastal443nm", "B2Blue490nm", "B3Green560nm", "B4Red665nm", "B5NIR705nm", "B6NIR740nm",
                 "B7NIR783nm", "B8NIR_broad842nm", "B9NIR940nm", "B10_1375nm", "B11_SWIR1610nm",
                 "B12_SWIR2190nm", "B8A_NIR865nm"]

#output file name
outputImage = fileNameBase + 'B'+''.join(bands)+'_stack.kea'

#output format (GDAL code)
outFormat = 'KEA'
outType = rsgislib.TYPE_32UINT

# stack bands using rsgislib 
rsgislib.imageutils.stackImageBands(Bands_VIS_NIR_SWIR_FileList, bandNamesList, outputImage, None, 0, outFormat, outType)
# stats and pyramids
rsgislib.imageutils.popImageStats(outputImage,True,0.,True)

# remove individual resampled 10m files
print("removing intermediate resampled files")
for b in Bands_resam_FileList:
    outFile = b[:-4]+'_10m.kea'
    os.remove(outFile)

Remote Sensing and GIS links page

Some time ago I posted a links page, I have added some more and rearranged it a bit:

Remote Sensing sensors and data:

• landsat.usgs.gov
  Landsat home page at the US Geological Survey.
• landsat.gsfc.nasa.gov
  NASA Landsat Science page.
• earthexplorer.usgs.gov
  US geological survey Earth Explorer interface for accessing Landsat (and other) satellite data.
• asterweb.jpl.nasa.gov
  ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) homepage. ASTER is an imaging instrument onboard Terra, the flagship satellite of NASA's Earth Observing System (EOS).
• www.astrium-geo.com/terrasar-x
  information on TERRASAR-X (Synthetic Aperture Radar satellite).
• SPOT 1-5, SPOT 6-7
  The SPOT series of commercially operated optical high-resolution multispectral satellites.
• The ESA Copernicus Programme
  The European Space Agency's Copernicus programme (previously known as the Global Monitoring for Environment and Security programme (GMES)), including the current and upcoming Sentinel series of Earth observation satellites.
• Website of Satellite Imaging Corporation
  Including information on the Worldview series of satellites.
• Shuttle Radar Topography Mission
  In 2000, the Space Shuttle flew a radar that produced a digital elevation map of the world. The 1 arcsecond data from that is now available for most of the world, previously only the USA had 1 arcsecond data publicly released, with the data covering the rest of the world released at 3 arcseconds resolution. Since September 2014, the 1 arcsecond data has been released for most of the world.

Earth-based Applications of Remote Sensing and GIS

• Arctic Sea-Ice Monitor
  By the International Arctic Research Center (IARC) in corporation with the Japan Aerospace Exploration Agency (JAXA).
• Johnny Ryan's guest blog at EGU on UAVs in West Greenland
  Johnny Ryan, PhD student of Prof. Alan Hubbard in Aberystwyth University, writing about the project using a fixed-wing unmanned aerial vehicle (UAV) in West Greenland to survey the cryosphere at fine temporal and spatial scales. Johnny tweets as @glaciology_uavs.
• Satellite Image Atlas of Glaciers of the World
  by the US Geological Society using Landsat and other remote sensing information.
• www.avex-asso.org/dossiers/wordpress/?page_id=2754
  A map of (modelled from urbanization) night sky light pollution across Europe. A map of Great Britain can be viewed at www.avex-asso.org/dossiers/wordpress/?page_id=127
• DarkSiteFinder.com
  A map of artificial light at night based on satellite observations from 2006, covering the whole world.
• Past Earth Network
  The idea behind the Past Earth Network (PEN) is that much can be learned about how our climate models will perform in a changed climate, by studying past climate. To make this happen, the network will improve communication between Palaeo-climate scientists and statisticians.
• Remote Sensing: Special Issue "Advances in Geographic Object-Based Image Analysis (GEOBIA)"
  a special issue of the open-access journal Remote Sensing, focusing on object-based methods of image analysis. This includes the paper Clewley et al. 2014 demonstrating RSGISLib and other Python-based open source software techniques.
• UAV studies of forests by the Institute of Aviation in Warsaw & the Forest Research Institute in Sękocin. Google Translate to English
  Using UAVs with optical and near-infrared cameras for forest health studies. Google Translate does make some mistranslations, but it is generally comprehensible if you ignore the bit about the 'raids' on the forest.
• Earth Science Picture of the Day
  a daily picture showcasing something in Earth Science.

Planetary Science Applications

• pds.jpl.nasa.gov
  NASA Planetary Data System.
• ode.rsl.wustl.edu
  PDS Geosciences Node Orbital Data Explorer, covering Mars, the Moon, Mercury and Venus.
• mars.jpl.nasa.gov
  Main NASA Mars page.
• jmars.mars.asu.edu
  JMARS is an acronym that stands for Java Mission-planning and Analysis for Remote Sensing. It is a geospatial information system (GIS) developed by Arizona State University's Mars Space Flight Facility to provide mission planning and data analysis tools to NASA's orbiters, instrument team members, students of all ages, and the general public.
• www.uahirise.org/hiview
  HiView is a downloadable software tool, the best way to explore HiRISE (the high resolution imaging instrument on NASA's Mars Reconnaissance Orbiter) images of the Martian surface at the full resolution of the imagery.
• ESA Mars Express Homepage
  The main page at the European Space Agency giving infromation about the Mars Express mission, images, and the latest news.
• Freie Universität Berlin
  web interface to the Mars Express High Resolution Stereo Camera image archive.
• Glaciers On Mars
  Stephen Brough, PhD student at Aberystwyth's blog about his research on glaciers on Mars.
• Mars-Antarctic Analogs
  website of Professor Dave Marchant of Boston University's Antarctic Research Group about the Dry Valleys of Antarctica as an analogue to conditions on Mars.
• The Extraordinary Martian Crater "Greg": A Photo Tour
  a crater in the mid-latitudes of the southern hemisphere of Mars, which shows glacier-like features in its walls. Paper by W. Hartmann et al.
• Mars Datasets (most GIS-ready)
  From the USGS, a list of links to various Mars datasets including mosaicked Mars Global Surveyor imagery and topography, and many others.
• Mars Clock
  What time is it on Mars?
• english.cntv.cn/special/lunarmission/index.shtml
  information on Chang'e 3 Chinese lunar mission.
• www.spaceflight101.com/change-3.html
  information on Chang'e 3 Chinese lunar mission.
• lunar.gsfc.nasa.gov
  Lunar Reconnaisance Orbiter homepage.
• saturn.jpl.nasa.gov
  NASA Cassini Orbiter page.
• CICLOPS
  Cassini Imaging Central Laboratry for Operations - Optical and near infrared imaging from the Cassini spaceprobe.
• wwwvims.lpl.arizona.edu
  Cassini Visual and Infrared Mapping Spectrometer website.
• New Horizons Pluto mission page
  One of the remotest sensors of all, NASAs New Horizons probe flying by Pluto on 14th July 2015.

Astronomy links

• Royal Astronomical Society guide: 'How to observe an eclipse safely'
• Great American Eclipse (August 21st 2017)
  On August 21, 2017, millions of people across the United States will see nature's most wondrous spectacle — a total eclipse of the Sun. It is a scene of unimaginable beauty; the Moon completely blocks the Sun, daytime becomes a deep twilight, and the Sun’s corona shimmers in the darkened sky. This is your guide to understand, prepare for, and view this rare celestial event. March 20th 2015 eclipse in Faroe Island and Svalbard.
• Heavens Above
  A website that details the passes of the International Space station, Iridium flares and other artificial satellites, as well as providing information on planets etc. visible in the sky.
• Cartes du Ciel
  Free planetarium software. The program enables you to draw sky charts, making use of the data in many catalogs of stars and nebulae. In addition the position of planets, asteroids and comets are shown.
• EmapWin
  Solar Eclipse prediction software, which shows the track of the moon's shadow on the Earth, and local circumstances including magnitude, start/end times and duration of totality for eclipses between 13000BC and 16999AD. Also see LmapWin for lunar eclipses.

Remote Sensing and GIS software, tutorials etc.

• spectraldifferences.wordpress.com
  Dan Clewley's blog on open-source remote sensing software.
• ArcGIS Help
  Online access to ArcGIS Help.
• www.qgis.org
  QGIS project page where you can find the free and open source QGIS software.
• The GeoAcademy
  A self-paced course on free & open source software for geospatial (FOSS4G) applications from the Free and Open Source Software 4 Geo Academy. 5 self-paced courses using QGIS (and a bit of GRASS7) are available.
• anitagraser.com
  QGIS blog by QGIS developer and data visualisation specialist Anita Graser.
• infogeoblog.wordpress.com
  A GIS blog containing tips and tutorials on QGIS.
• fromgistors.blogspot.com
  Blog by Luca Congedo, the author of the Semi-Automatic Classification Plugin for QGIS that allows for supervised Land Cover classifications.
• GRASS GIS 7.0.1 svn Reference Manual
  This reference manual details the use of modules distributed with Geographic Resources Analysis Support System (GRASS), an open source (GNU GPLed), image processing and geographic information system (GIS).
• gracilis.carleton.ca/CUOSGwiki
  Carleton University Open Source GIS tutorials.
• Viking:
  a free and open source program to manage GPS data. This can import data from a GPS device and add map layers from OpenStreetMap and digital elevation model data.
• www.gislounge.com
  GIS information portal.
• www.movable-type.co.uk/scripts/latlong-gridref.html
  Online converter in Javascript from Lat/Long to OSGB grid references and vice versa.
• Grid Inquest
  -Downloadable Grid Inquest software from the UK Ordnance Survey to convert between Lat/long and OSGB grid references. An online batch converter is also available.
• Spatial Reference
  An online database of spatial reference descriptions in a large number of geographic and projected coordinate systems.
• Flex Projector
  Flex Projector is a freeware, cross-platform application for creating custom world map projections. The intuitive interface allows users to easily modify dozens of popular world map projections - the possibilities range from slight adjustments to making completely new projections. Flex Projector is intended as a tool for practicing mapmakers and students of cartography.
• Opticks
  free open source image analysis software.
• Geomorphons App
  Geomorphons are a pattern recognition method of terrain analysis developed by Tomasz Stepinski and Jaroslaw Jasiewicz. It is available as a Web-based utility that allows users to calculate geomorphons maps from their own DEMs (for smaller datasets) and also as a GRASS7 module. Blog post including video of lecture about it.
• LandSerf
  Written by Prof. Jo Wood, LandSerf is a freely available Geographical Information System (GIS) for the visualisation and analysis of surfaces. Applications include visualisation of landscapes; geomorphological analysis; gaming development; GIS file conversion; map output; archaeological mapping and analysis; surface modelling and many others. It runs on any platform that supports the Java Runtime Environment (Windows, MacOSX, Unix, Linux etc. I used it myself in my dissertation on Martian glaciers.

Python

• www.python.org/doc
  The official Python website with online documentation and tutorials.
• Code Academy Python Tutorials
  The Code Academy Python track with interactive tutorials.
• Numpy tutorial
  NumPy is the fundamental package for scientific computing with Python. A tutorial with a set of 100 exercises is available at this site.
• www.rsgislib.org
  Remote Sensing and GIS library: a collection of tools for processing remote sensing and GIS datasets, used via a Python library or XML bindings.
• bitbucket.org/petebunting/arcsi
  ARCSI atmospheric correction software (Python).
• www.py6s.rtwilson.com
  Py6S (Second Simulation of the Satellite Signal in the Solar Spectrum) - a Python library implementing atmospheric correction models.
• videolectures.net/mloss08_hunter_mat
  video lecture on matplotlib (plotting library for Python) by one of its developers (dates from 2008).
• Matplotlib Python plotting library
  Matplotlib homepage with documentation on using matplotlib to create plots of data in Python.
• Video lectures by Jake VanderPlas
  Tutorials on Python scikit-learn and AstroML machine learning libraries, and Matplotlib data visualization.
• Filtergraph
  a website allowing use of the power of matplotlib in a GUI within the browser without the need for coding by the user.
• FastKML Python library
  read and write KML files suitable for Google Earth.
• python4astronomers.github.io
• www.astrobetter.com/visualization-fun-with-python-2d-histogram-with-1d-histograms-on-axes
• geospatialpython.com
  Joel Lawhead's Geospatial Python blog.
• code.google.com/p/pyshp
  Python Shapefile library.
• code.google.com/p/geopy/wiki/GettingStarted
  geopy - geocoding for python

HTML, CSS and Javascript

• Codecademy HTML and CSS tutorials
  the web programming track at Codecademy. Javascript tutorials also are available.
• What colour is it?
  translates the time to an HTML colour.
• HTML Color Names
  A list of named HTML colours.
• Shay Howe's HTML and CSS tutorials
• Learn CSS Layout
  online tutorial on the layout features of CSS styling.
• d3.js data visualization Javascript library
• www.w3schools.eu/2012/07/webgl-essentials-part-i
  Tutorial for WebGL. WebGL is an in-browser 3D renderer based on OpenGL, which lets you display your 3D content directly into an HTML5 page.
• www.pheelicks.com/2014/03/rendering-large-terrains
  An example of rendering a large terrain in 3D using WebGL.

Online Mapping

• www.openstreetmap.org
  OpenStreetMap - a free and user-editable online map.
• nls.tileserver.com
  National Library of Scotland Historical Ordnance Survey maps of Great Britain dating from 1920s-1940s.
• www.gravitystorm.co.uk
  Website of OSM developer Andy Allan.
• www.ravenfamily.org/andyg/openstreetmap.htm
  OSM data with topography of UK and Ireland exported for Garmin GPS units.
• Multilingual OpenStreetMap Test site
  Jochen Topf's test site allowing a choice of language labels rendering OpenStreetMap.
• www.elsewhere.org/journal/gmaptogpx
  A Javascript tool to export directions as a GPX file from Google Maps.
• www.perfilderuta.es/perfil.php?lng=en
  Draw the elevation profile of your bicycle routes.
• maps.vlasenko.net
  Soviet military topographic maps. The 1:500k series are also available from this website: landkartenarchiv.de.
• The Interactive Map of Middle-Earth
  The LoTR project has created an interactive map of Middle Earth in Tolkein's Lord of the Rings.

Downloadable GIS data

• UK Ordnance Survey Open Data
  Various raster and vector layers are available.
• freegisdata.rtwilson.com
  A categorised list of freely available GIS data compiled by Robin Wilson.
• Data extracts from OpenStreetMap
  Geofabrik's free download server. This server has data extracts from the OpenStreetMap project which are normally updated every day. Select your continent and then your country of interest.
• Hill Bagging
  various lists of hills and mountains in the British Isles.
• www.renewables-atlas.info
  The Atlas of UK Marine Renewable Energy Resources.
• Quantarctica
  A collection of datasets focused on Antarctica for use with QGIS.
• GSHHG
  A Global Self-consistent, Hierarchical, High-resolution Geography Database. The GSHHG is a high-resolution geography data set, amalgamated from two databases in the public domain: World Vector Shorelines (WVS) and CIA World Data Bank II (WDBII). The WDBII source also provides all political borders and rivers.
• 1:625k scale Geology of Britain and Northern Ireland
  Available free to download from the British Geological Survey.

Cartography and Data Visualisation Advice

• Colorbrewer2
  Colour Palettes, including selecting palettes to reproduce effectively in print, and for colour-blind viewers.
• iwanthue
  Colours for data scientists. Generate and refine palettes of optimally distinct colors.
• www.jasondavies.com
  Freelance data visualisation consultant Jason Davies' page.
• earthobservatory.nasa.gov/blogs/elegantfigures
  NASA blog on data visualisation.
• visual.ly
  Data visualisation online community and blog.
• www.shadedrelief.com
  Ideas and Techniques about Relief Presentation on Maps. Includes Cleantopo2, a cleaned of artifacts topographic and bathymetric dataset for cartographic purposes.

Google Fusion Tables

• support.google.com/fusiontables/answer/184641
  how to use Google Fusion tables to make a visualisation of data on a customized Google Map.
• www.curriculumkernewek.org.uk/map.html
  an example that I did much of the coding for, showing religious themed historical sites in Cornwall, when I was doing voluntary work with Azook.
• Cornish Memory Map
  a searchable collection of historical photographs displayed on a map of Cornwall.
• Map Icons Collection
  a set of more than 1000 free and customizable icons to use as placemarks for your POI (Point of Interests) locations on your maps.

GIS Data visualisation examples

• The DataShine mapping platform
  from the UCL Centre for Advanced Spatial Analysis. Shows a selection of data from the 2011 England and Wales and Cornwall census. The visualisation clips the output polygons to where there are buildings according to OS Opendata vector maps.
• 100-Great Geosites
  Interactive Map for UK and Ireland, showing the 100 Great Geosites, selected by The Geological Society.
• Geology of Britain viewer
  A web-based map of the geology of Britain from the British Geological Survey.
• SahulTime
  is an ongoing project to create a visual, interactive representation of the Earth's history. Observe the geography of Australasia over the last 120,000 years.
• ZyGrib
  Visualization of weather data. The program can download NOAA (GFS Model) weather forecasts for 8 days ahead for anywhere in the world.
• earth.nullschool.net
  Visualization of global weather data, with a Javascript data visualization.
• www.carbonmap.org
  A data visualization project for "Making sense of climate change responsibility and vulnerability", created by Kiln (website with other examples).
• US Geological Survey latest earthquakes
  Part of the National Earthquake Hazards Reduction Program (NEHRP). The latest earthquakes around the world are displayed on a map.
• Video of TEDxEastEnd lecture by Prof. Jo Wood
  about London Moves, video visualisation of 16 million cycle journeys in London. Website 'Bicycle visualization and analysis' with further information about the research.

General Mapping Fun

• Google Maps Mania
  a lot of interesting things done with maps. warning: procrastination alert.
• Strange Maps
  warning: procrastination alert.
  
• LANDKARTENARCHIV
  A website (in German) with many examples of historical maps, including many examples of the Soviet Union's military maps at 1:500k and 1:1M scale, and among other things maps with various European powers realised as animals (often this is 1st world war propaganda - from all sides).
• The Clear Mapping Company
  A business based in Cornwall, offering quality cartographic and design services on a contract basis for clients of all sizes.

Travel time maps

• property.mapumental.com
  find areas within a certain travel time by public transport to a location. This assumes you can walk on water.
• traveltime.propertywide.co.uk
  similar, allows using different kinds of transport.

LaTeX (Document processing)

• www.andy-roberts.net/writing/latex
  Getting to Grips with LaTeX by Andrew Roberts.
• texblog
  Blog with tips and tricks about LaTeX editing.
• LaTeX Wikibook
  a good reference. Includes how to make LaTeX produce a page size optimized for many tablets in the Page Layout chapter.

Art/Science collaboration

• Art Science Climate Change
  by Julian Ruddock. Website showing his projects that are based on art and science collaboration in relation to climate change.

Citizen Science and crowdsourced cloud computing

• Climateprediction.net
  Contribute to climate research with your own computer by running simulations.

Games

• geoguessr.com
  Geoguessr - Google Street View guess the location game.
• locatestreet.com/game.php
  similar.
• pursued.nemesys.hu
  this one has a time limit.
• inear.se/urbanjungle
  Urban Jungle Street View.

Object-based segmentation of topography with RSGISLib

The RSGISLib (Remote Sensing and GIS) Python library written by Pete Bunting and Daniel Clewley provides a number of features, among them segmentation of images to objects.

This can not only be applied to what one conventionally thinks of as images, but also topographic layers. I thought I'd practice this on Earth first before trying to do this for Mars as I will be for my dissertation.

Using Space Shuttle Radar data (freely available - I got it via the program Viking) I obtained the elevation of the British Isles (excluding Shetland) and using GDAL via QGIS and the command line, created slope and aspect layers. I then transformed the aspect to remove the discontinuity at 360-0 deg, using degrees from N, so that 180 is south facing, east and west are both 90 etc.

Using RSGISLib it is possible to segment to objects. Here I show some results of doing so, using a layerstacked image with elevation, slope and angle from N. I have set the minimum connected object size to 1000 pixels. With the topographic data gridded at 73m, this means objects about 5.5 sq. km or larger.


Visualisation is a gaussian stretch in TuiView, setting red to aspect, green to slope, and blue to elevation, showing mean values for each segment.

Now I show a few of the actual segments without the values, with colours assigned in RSGISLib for visualisation. It is possible to populate a Raster Attribute Table to add data to the segments for a land cover classification.

From the Isles of Scilly to the Isle of Wight:

Wales, and central England.

 Zooming in to mid Wales:

By changing the object size, it is possible to do this at different scales. This is part of the segmentation for a minimum object size of 16384 pixels (that is about 89 sq. km) equivalent to a square 9.5km a side:

The thing that makes geospatial data interesting is how what you see in it changes depending on what scale you look at it and how you visualise it.

List of Remote Sensing and GIS links

Here is a list of Remote Sensing and GIS links that may be useful and/or interesting:

Remote Sensing and GIS software, tutorials etc.

 

http://spectraldifferences.wordpress.com/about - Dan Clewley's blog on open-source remote sensing software.

http://resources.arcgis.com/en/help - Online access to ArcGIS Help.

http://opticks.org - Opticks - free open source image analysis software.

http://www.qgis.org - QGIS project page where you can find the free and open source QGIS software.

http://foss4geo.org  - A self-paced course on QGIS from the Free and Open Source Software 4 Geo Academy. There are two modules currently, an introduction and cartography (June 2014) with more coming soon.

http://anitagraser.com - QGIS blog by QGIS developer and data visualisation specialist Anita Graser.

http://infogeoblog.wordpress.com - A GIS blog containing tips and tutorials on QGIS.

http://fromgistors.blogspot.com  Blog by Luca Congedo, the author of the Semi-Automatic Classification Plugin for QGIS that allows for supervised Land Cover classifications.

http://gracilis.carleton.ca/CUOSGwiki Carleton University Open Source GIS tutorials.

http://sourceforge.net/apps/mediawiki/viking/index.php?title=Main_Page - Viking: a free and open source program to manage GPS data. This can import data from a GPS device and add map layers from OpenStreetMap and digital elevation model data.

http://www.gislounge.com GIS information portal.

http://www.movable-type.co.uk/scripts/latlong-gridref.html Online converter in Javascript from Lat/Long to OSGB grid references and vice versa.
http://www.ordnancesurvey.co.uk/business-and-government/help-and-support/navigation-technology/os-net/grid-inquest.html Downloadable Grid Inquest software to convert between Lat/long and OSGB grid references. An online batch converter is also available.

http://www.w3schools.eu/2012/07/webgl-essentials-part-i
Tutorial for WebGL. WebGL is an in-browser 3D renderer based on OpenGL, which lets you display your 3D content directly into an HTML5 page.

Python:

 

https://www.python.org/doc - The official Python website with online documentation and tutorials.


http://www.rsgislib.org - Remote Sensing and GIS library: a collection of tools for processing remote sensing and GIS datasets, used via a Python library or XML bindings.

https://bitbucket.org/petebunting/arcsi - ARCSI atmospheric correction software (Python).

http://www.py6s.rtwilson.com - Py6S (Second Simulation of the Satellite Signal in the Solar Spectrum) - a Python library implementing atmospheric correction models.

http://videolectures.net/mloss08_hunter_mat - video lecture on matplotlib (plotting library for Python) by one of its developers (dates from 2008).

a few links from astronomers - some of which may be applicable to remote sensing:
http://python4astronomers.github.io
http://www.astrobetter.com/visualization-fun-with-python-2d-histogram-with-1d-histograms-on-axes

http://geospatialpython.com - Joel Lawhead's Geospatial Python blog.

http://code.google.com/p/pyshp - Python Shapefile library.
http://code.google.com/p/geopy/wiki/GettingStarted geopy - geocoding for python

Online Mapping

 

http://www.openstreetmap.org OpenStreetMap - a free and user-editable online map.
http://www.gravitystorm.co.uk Website of OSM developer Andy Allan.
http://www.ravenfamily.org/andyg/openstreetmap.htm OSM data with topography of UK and Ireland exported for Garmin GPS units.
www.elsewhere.org/journal/gmaptogpx A Javascript tool to export directions as a GPX file from Google Maps.

http://www.perfilderuta.es/perfil.php?lng=en Draw the elevation profile of your bicycle routes.
http://maps.vlasenko.net Soviet military topographic maps.

Downloadable GIS data

 

http://www.ordnancesurvey.co.uk/business-and-government/products/opendata-products.html UK Ordnance Survey Open Data. Various raster and vector layers are available.

http://freegisdata.rtwilson.com - A categorised list of freely available GIS data compiled by Robin Wilson.

Cartography and Data Visualisation Advice

 

http://colorbrewer2.org - Colour Palettes, including selecting palettes to reproduce effectively in print, and for colour-blind viewers.
http://tools.medialab.sciences-po.fr/iwanthue -  Colours for data scientists. Generate and refine palettes of optimally distinct colors.

http://www.jasondavies.com  Freelance data visualisation consultant Jason Davies' page.

http://earthobservatory.nasa.gov/blogs/elegantfigures NASA blog on data visualisation.

http://visual.ly Data visualisation online community and blog.

http://www.pheelicks.com/2014/03/rendering-large-terrains An example of rendering a large terrain in 3D using WebGL.

http://www.shadedrelief.com Ideas and Techniques about Relief Presentation on Maps. Includes www.shadedrelief.com/cleantopo2 a cleaned of artifacts topographic and bathymetric dataset for cartographic purposes.

GIS Data visualisation examples

http://datashine.org.uk The DataShine mapping platform from the UCL Centre for Advanced Spatial Analysis. Shows a selection of data from the 2011 England and Wales and Cornwall census. The visualisation clips the output polygons to where there are buildings according to OS Opendata vector maps.

General Mapping Fun

https://support.google.com/fusiontables/answer/184641 - how to use Google Fusion tables to make a visualisation of data on a customized Google Map.
http://www.curriculumkernewek.org.uk/map.html - an example that I did much of the coding for.

http://googlemapsmania.blogspot.co.uk - a lot of interesting things done with maps (warning - procrastination alert!).

http://bigthink.com/blogs/strange-maps - Strange Maps (warning - procrastination alert!)

Travel time maps

 

http://property.mapumental.com - find areas within a certain travel time by public transport to a location. This assumes you can walk on water
http://traveltime.propertywide.co.uk similar, allows using different kinds of transport

Remote Sensing data and information on sensors:

http://earthexplorer.usgs.gov US geological survey Earth Explorer interface for accessing Landsat (and other) satellite data.
http://landsat.usgs.gov Landsat home page.
http://landsat.gsfc.nasa.gov NASA Landsat Science page.


http://asterweb.jpl.nasa.gov ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) homepage. ASTER is an imaging instrument onboard Terra, the flagship satellite of NASA's Earth Observing System(EOS) 

http://www.astrium-geo.com/terrasar-x information on TERRASAR-X (Synthetic aperture radar satellite)

http://www.astrium-geo.com/en/4388-spot-1-to-spot-5-satellite-images
http://www.astrium-geo.com/en/147-spot-6-7-satellite-imagery  SPOT 1 to 7 (optical high-resolution multispectral commercially operated satellites).

http://www.esa.int/Our_Activities/Observing_the_Earth/Copernicus  The Copernicus programme (previously known as the Global Monitoring for Environment and Security programme (GMES)), including the current and upcoming Sentinel series of earth observation satellites.

http://www.satimagingcorp.com Website of Satellite Imaging Corporation - including information on Worldview series of satellites.

Earth-based Applications

 

http://www.renewables-atlas.info - The Atlas of UK Marine Renewable Energy Resources.

http://www.quantarctica.org - Quantarctica - A collection of datasets focused on Antarctica for use with QGIS.

http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cg  Arctic Sea-Ice Monitor, by the International Arctic Research Center (IARC) in corporation with the Japan Aerospace Exploration Agency (JAXA) .

http://www.avex-asso.org/dossiers/wordpress/?page_id=2754 A map of (modelled from urbanization) night sky light pollution across Europe. A map of Great Britain can be viewed at http://www.avex-asso.org/dossiers/wordpress/?page_id=127

http://sahultime.monash.edu.au  SahulTime is an ongoing project to create a visual, interactive representation of the Earth's history. Observe the geography of Australasia over the last 120,000 years.

http://www.zygrib.org Visualization of weather data. The program can download NOAA  (GFS Model) weather forecasts for 8 days ahead for anywhere in the world.

http://www.carbonmap.org - A data visualization project for "Making sense of climate change responsibility and vulnerability", created by Kiln (website with other examples).

Planetary Science Applications

 

http://pds.jpl.nasa.gov NASA Planetary Data System.
http://ode.rsl.wustl.edu  PDS Geosciences Node Orbital Data Explorer, covering Mars, the Moon, Mercury and Venus.
http://mars.jpl.nasa.gov Main NASA Mars page.
http://jmars.mars.asu.edu JMARS is an acronym that stands for Java Mission-planning and Analysis for Remote Sensing. It is a geospatial information system (GIS) developed by ASU's Mars Space Flight Facility to provide mission planning and data-analysis tools to NASA's orbiters, instrument team members, students of all ages, and the general public.
http://www.uahirise.org/hiview HiView is a downloadable software tool, the best way to explore HiRISE (the high resolution imaging instrument on NASA's Mars Reconnaissance Orbiter) images of the Martian surface at the full resolution of the imagery.
http://hrscview.fu-berlin.de/cgi-bin/ion-p?page=entry2.ion  Freie Universität Berlin web interface to the Mars Express High Resolution Stereo Camera image archive.

http://english.cntv.cn/special/lunarmission/index.shtml information on Chang'e 3 Chinese lunar mission.
http://www.spaceflight101.com/change-3.html information on Chang'e 3 Chinese lunar mission.
http://lunar.gsfc.nasa.gov Lunar Reconnaisance Orbiter homepage.

http://saturn.jpl.nasa.gov NASA Cassini Orbiter page.
http://www.ciclops.org/index.php CICLOPS (Cassini Imaging Central Laboratry for Operations) i.e. optical and near infrared imaging.
http://wwwvims.lpl.arizona.edu Cassini Visual and Infrared Mapping Spectrometer website.

LaTeX (Document processing)

 

http://www.andy-roberts.net/writing/latex  Getting to Grips with LaTeX by Andrew Roberts.

Games

 

http://geoguessr.com - Geoguessr - Google Street View guess the location game.
http://locatestreet.com/game.php - similar
http://pursued.nemesys.hu - this one has a time limit.

http://inear.se/urbanjungle - Urban Jungle Street View.