Have you read the top Pixalytics blogs of 2017?

World Cloud showing top 100 words from Pixalytics 2017 blogs

In our final blog of the year, we’re looking back at our most popular posts of the last twelve months. Have you read them all?

Of the top ten most read blogs, nine were actually written in previous years. These were:

You’ll notice that this list is dominated by our annual reviews of the number of satellites, and Earth observation satellites, orbiting the Earth. It often surprises us to see where these blogs are quoted and we’ve been included in articles on websites for Time Magazine, Fortune Magazine and the New Statesman to name a few!

So despite only being published in November this year coming in as the fourth most popular blog of the year was, unsurprisingly:

For posts published in 2017, the other nine most popular were:

2017 has been a really successful one for our website. The number of the views for the year is up by 75%, whilst the number of unique visitors has increased by 92%!

Whilst hard work, we do enjoy writing our weekly blog – although staring at a blank screen on a Wednesday morning without any idea of what we’ll publish a few hours later can be daunting!

We’re always delighted at meetings and conferences when people come up and say they read the blog. It’s nice to know that we’re read both within our community, as well as making a small contribution to informing and educating people outside the industry.

Thanks for reading this year, and we hope we can catch your eye again next year.

We’d like to wish everyone a Happy New Year, and a very successful 2018!

Big Data From Space

Last week I attended the 2017 Conference on Big Data from Space (BiDS’17) that was held in Toulouse, France. The conference was co-organised by the European Space Agency (ESA), the Joint Research Centre (JRC) of the European Commission (EC), and the European Union Satellite Centre (SatCen). It aimed to bring together people from multiple disciplines to stimulate the exploitation Earth Observation (EO) data collected in space.

The event started on Tuesday morning with keynotes from the various co-organising space organisations. Personally, I found the talk by Andreas Veispak, from the European Commission’s (EC) DG GROW department which is responsible for EU policy on the internal market, industry, entrepreneurship and SMEs, particularly interesting. Andreas has a key involvement in the Copernicus and Galileo programmes and described the Copernicus missions as the first building block for creating an ecosystem, which has positioned Europe as a global EO power through its “full, free and open” data policy.

The current Sentinel satellite missions will provide data continuity until at least 2035 with huge amounts of data generated, e.g., when all the Sentinel satellite missions are operational over 10 petabytes of data per year will be produced. Sentinel data has already been a huge success with current users exceeding what was expected by a factor of 10 or 20 and every product has been downloaded at least 10 times. Now, the key challenge is to support these users by providing useful information alongside the data.

The ESA presentation by Nicolaus Hanowski continued the user focus by highlighting that there are currently over 100 000 registered Copernicus data hub users. Nicolaus went on to describe that within ESA success is now being measured by use of the data for societal needs, e.g., the sustainable development goals, rather than just the production of scientific data. Therefore, one of the current aims is reduce the need for downloading by having a mutualised underpinning structure, i.e. the Copernicus Data and Information Access Services (DIAS) that will become operational in the second quarter of 2018, which will allow users to run their computer code on the data without the need for downloading. The hope is that this will allow users to focus on what they can do with the data, rather than worrying around storing it!

Charles Macmillan from JRC described their EO Data and Processing Platform (JEODPP) which is a front end based around the Jupyter Notebook that allows users to ask questions using visualisations and narrative text, instead of just though direct programming. He also noted that increasingly the data needed for policy and decision making is held by private organisations rather than government bodies.

The Tuesday afternoon was busy as I chaired the session on Information Generation at Scale. We had around 100 people who heard some great talks on varied subjects such as mass processing of Sentinel & Landsat data for mapping human settlements, 35 years of AVHRR data and large scale flood frequency maps using SAR data.

‘Application Of Earth Observation To A Ugandan Drought And Flood Mitigation Service’ poster

I presented a poster at the Wednesday evening session, titled “Application Of Earth Observation To A Ugandan Drought And Flood Mitigation Service”. We’re part of a consortium working on this project which is funded via the UK Space Agency’s International Partnership Programme. It’s focus is on providing underpinning infrastructure for the Ugandan government so that end users, such as farmers, can benefit from more timely and accurate information – delivered through a combination of EO, modelling and ground-based measurements.

It was interesting to hear Grega Milcinski from Sinergise discuss a similar approach to users from the lessons they learnt from building the Sentinel Hub. They separated the needs of science, business and end users. They’ve chosen not to target end users due to the challenges surrounding the localisation and customisation requirements of developing apps for end users around the world. Instead they’ve focussed on meeting the processing needs of scientific and business users to give them a solid foundation upon which they can then build end user applications. It was quite thought provoking to hear this, as we’re hoping to move towards targeting these end users in the near future!

There were some key technology themes that came of the presentations at the conference:

  • Jupyter notebooks were popular for frontend visualisation and data analytics, so users just need to know some basic python to handle large and complex datasets.
  • Making use of cloud computing using tools such as Docker and Apache Spark for running multiple instances of code with integrated parallel processing.
  • Raw data and processing on the fly: for both large datasets within browsers and by having the metadata stored so you can quickly query before committing to processing.
  • Analysis ready data in data cubes, i.e. the data has been processed to a level where remote sensing expertise isn’t so critical.

It was a great thought provoking conference. If you’d like to get more detail on what was presented then a book of extended abstracts is available here. The next event is planned for 19-21 February 2019 in Munich, Germany and I’d highly recommend it!

Earth observation satellites in space in 2017?

Artist’s rendition of a satellite – paulfleet/123RF Stock

Earth Observation (EO) satellites currently account for just over a third of all the operational satellites orbiting the Earth. As we described two weeks ago, according to the Union of Concerned Scientists database there were 1 738 operational satellites at the end of August 2017, and 620 of these have a main purpose of either EO or Earth Science.

This represents a massive 66% increase in the number of EO satellites from our 2016 update, and the percentage of overall active satellites is also up from one quarter. These figures demonstrate, once again, that EO is a growing industry.

What do Earth observation satellites do?
Looking more closely at what EO satellites actually do demonstrates that despite increases in satellite numbers in almost all categories, it’s clearly growth in optical imaging which is the behind this significant increase. The purposes of active EO satellites in 2017 are:

  • Optical Imaging: 327 satellites representing a 98% increase on last year
  • Radar imaging: 45 satellites, a 32% increase on last year
  • Infrared imaging: 7 satellites, no change to last year
  • Meteorology: 64 satellites, a 73% increase on last year
  • Earth Science: 60 satellites, a 13% increase on last year
  • Electronic intelligence: 50 satellites, a 6% increase on last year
  • 14 satellites with other purposes, a 133% increase on last year
  • 51 satellites simply list EO as their purpose, a 100% increase on last year

Who controls Earth observation satellites?
Despite the huge increase in EO satellites, the number of countries who control them has not seen the same growth. This year there are 39 different countries listed with EO satellites, an increase of only 15% on last year. In addition, there are satellites run by multinational agencies such as the European Space Agency (ESA).

The USA leads the way controlling over half the EO satellites, although this is largely due to Planet who account for 30% on their own! Following USA is China with 14.4%, and then come India, Japan and Russia who each have over 3%.

The USA is followed by China with about 20%, and Japan and Russia come next with around 5% each. The UK is only listed as controller on 4 satellites all related to the DMC constellation, although we are also involved in the ESA satellites.

Size of Earth observation satellites
It’s interesting to look out the size breakdown of these satellites which shows the development of the small satellite. For this breakdown, we’ve classed satellites into four groups:

  • Large satellites with a launch mass of over 500kg
  • Small satellites with a launch mass between 100 and 500 kg.
  • Microsats with a launch mass between 10 and 100 kg.
  • Nanosats/Cubesats with a launch mass below 10 kg.

For the current active EO satellites there are:

  • 904 large satellites equating to 52.01%
  • 178 small satellites equating to 10.24%
  • 145 microsats equating to 8.34%
  • 409 Nanosats/Cubesats equating to 23.53%
  • The remaining 102 satellites do not have a launch mass specified.

Who uses the Earth observation satellites?

There has also been significant movement in the breakdown of EO satellites users since 2016. The influence of small commercial satellites undertaking optical imaging is again apparent. In 2017 the main users for EO were:

  • Commercial users with 44.68% of satellites (up from 21% in 2016)
  • Government users with 30.81% (down from 44% in 2016)
  • Military users with 19.45% (down from 30% in 2016)
  • Civil users with 5.16% (approximately the same as in 2016)

It should be noted that some of these satellites have multiple users.

Orbits of Earth observation satellites
In terms of altitude, unsurprisingly the vast majority, 92.25%, of EO satellites are in low earth orbits, 6.45% are in geostationary orbits and 1.3% are in an elliptical orbits.
There is a much greater variation in type of orbits:

  • 415 in a sun-synchronous orbit
  • 234 in a non-polar inclined orbit
  • 17 in a polar orbit
  • 8 in an equatorial orbit
  • 5 in an elliptical orbit
  • 5 in a Molniya orbit (highly eccentric elliptical orbits of approximately 12 hours)
  • 45 satellites do not have a type of orbit listed

Few interesting facts about active Earth observation satellites

  • Oldest active EO satellite is the Brazilian SCD-1 Meteorology/Earth Science satellite.
  • Valentine’s Day (14th February) 2017 saw Planet launch its Flock 3P meaning that 88 active EO satellites were launched on that day.
  • Most popular launch site is Satish Dhawan Space Centre operated by Indian Space Research Organisation (ISRO) who have put 169 into space.
  • ISRO’s Polar Satellite Launch Vehicle is also the most popular launch vehicle with 114 satellites.
  • The EO satellite furthest away from the Earth is the USA’s Electronic Intelligence satellite Trumpet 3 which has an apogee of 38 740 km.

What’s next?
It’s not clear whether the rapid growth in the number of EO satellites will continue into 2018. Planet, one of the key drivers, announced earlier this month that they had successfully completed their objective to image the globe’s entire landmass every day – which is a massive achievement!

That’s not say that Planet won’t push on further with new ideas and technologies, and other companies may move into that space too. China launched a number of EO satellites last weekend and there are already a number of interesting satellites planned for launch between now and the middle of 2018 including, Cartosat-2ER, NovaSAR-S, GOES-S and Sentinel-3B to name a few. .

One thing is for certain, there is a lot collected EO data out there, and it is increasing by the day!

To TEDx Speaking and Beyond!

Back in April I received an invitation to speak at the ‘One Step Beyond’ TEDx event organised at the National Space Centre in Leicester, with my focus on the Blue Economy and Earth Observation (EO).

We’ve been to a few TEDx events in the past and they’ve always been great, and so I was excited to have the opportunity to join this community. Normally, I’m pretty relaxed about public speaking. I spend a lot of time thinking about what I’m going to say, but don’t assemble my slides until a couple of days beforehand. This approach has developed in part because I used to lecture – where I got used to talking for a while with a few slides – but also because I always like to take some inspiration from the overall mood of the event I’m talking at. This can be through hearing other speakers, attending workshops or even just walking around the local area.

TEDx, however, was different. There was a need to have the talk ready early for previewing and feedback, alongside producing stunning visuals and having a key single message. So, for a change, I started with a storyboard.

My key idea was to get across the sense of wonder I and many other scientists share in observing the oceans from space, whilst also emphasising that anyone can get involved in protecting this natural resource. I echoed the event title by calling my talk “Beyond the blue ocean” as many people think of the ocean as just a blue waterbody. However, especially from space, we can see the beauty, and complexity, of colour variations influenced by the microscopic life and substances dissolved and suspended within it.

I began with an with an image called the ‘Pale Blue Dot’ that was taken by Voyager 1 at a distance of more than 4 billion miles from Earth, and then went with well-known ‘Blue Marble’ image before zooming into what we see from more conventional EO satellites. I also wanted to take the audience beyond just optical wavelengths and so displayed microwave imagery from Sentinel-1 that’s at a similar spatial resolution to my processed 15 m resolution Sentinel-2 data that was also shown.

Dr Samantha Lavender speaking at the One Step Beyond TEDx event in Leicester. Photo courtesy of TEDxLeicester

The satellite imagery included features such as wind farms, boats and phytoplankton blooms I intended to discuss. However, this didn’t quite to go to plan on my practice run through! The talk was in the planetarium at the National Space Centre, which meant the screen was absolutely huge – as you can see in the image to the right. However, with the lights on in the room the detail in the images was really difficult to see. The solution for the talk itself was to have the planetarium in darkness and myself picked out by two large spotlights, meaning that the image details were visible to the audience but I couldn’t see the audience myself.

The evening itself took place on the 21st September, and with almost two hundred in the audience I was up first. I was very happy with how it went and the people who spoke to me afterwards said they were inspired by what they’d seen. You can see for yourself, as the talk can be found here on the TEDx library. Let me know what you think!

I was followed by two other fantastic speakers who gave inspiring presentations and these are also up on the TEDx Library. Firstly, Dr Emily Shuckburgh, Deputy Head of Polar Oceans team at British Antarctic Survey discussed “How to conduct a planetary health check”; and she was followed by Corentin Guillo, CEO and Founder of Bird.i, who spoke about “Space entrepreneurship, when thinking outside the box is not enough”.

The whole event was hugely enjoyable and the team at TEDx Leicester did an amazing job of organising it. It was good to talk to people after the event, and it was fantastic that seventy percent of the audience were aged between 16 and 18. We need to do much more of this type of outreach activities to educate and inspire the next generation of scientists. Of course, for me, the day also means that I can now add TEDx Speaker to my biography!

Looking To Earth Observation’s Future

Artist’s view of Sentinel-3. Image courtesy of ESA–Pierre Carril.

The future is very much the theme for Earth Observation (EO) in Europe this week.

One of the biggest potential impacts for the industry could come out of a meeting that took place yesterday, 7 November, in Tallinn, Estonia as part of European Space Week. It was a meeting between the European Union (EU) and the European Space Agency (ESA) to discuss the next steps for the Copernicus programme beyond 2020. This is important in terms of not only continuing the current Sentinel missions, but also expanding what is monitored. There are concerns over gaps in coverage for certain types of missions which Europe could help to fill.

As an EO SME we’re intrigued to see the outcomes of these discussions as they include a focus on how to leverage Copernicus data more actively within the private sector. According to a recent Industry Survey by the European Association of Remote Sensing Companies (EARSC), there are just over 450 EO companies operating in Europe, and 66% of these are micro companies like Pixalytics – defined by having less than ten employees. This rises to 95% of all EO European companies if you include small businesses – with between 10 and 50 employees.

Therefore, if the EU/ESA is serious about developing the entrepreneurial usage of Copernicus data, it will be the small and micro companies that will make the difference. As these companies grow, they will need high skilled employees to support them.

Looking towards the next generation of EO scientists, the UK Space Agency announced seven new outreach projects this week inspire children to get involved in space specifically and more widely, to increase interest in studying science, technology, engineering and mathematics (STEM) subjects. The seven projects are:

  1. Glasgow Science Festival: Get me into orbit!
  2. Triathlon Trust: Space to Earth view
  3. Mangorolla CIC: Space zones ‘I’m a Scientist’ and ‘I’m an Engineer’
  4. Institute for Research in Schools: MELT: Monitoring the Environment, Learning for Tomorrow
  5. The Design and Technology Association: Inspiring the next generation: design and technology in space
  6. European Space Education Resource Office-UK: James Webb Space Telescope: Design challenge
  7. Children’s Radio UK (Fun Kids): Deep Space High – UK Spaceports

There will be a total of £210,000 invested in these. We’re particularly excited to see the MELT project which will get students to use EO data to analyse what is happening at the two poles.

Each of these elements will help shape the EO industry in this country. With the UK committed to remaining within ESA, decisions on the future of the Copernicus programme will provide a strong strategic direction for both the space and EO industries in Europe. Delivering on that direction will require the next generation workforce who will come from the children studying STEM subjects now.

Both the strategic direction, and associated actions to fulfil those ambitions, are vital for future EO success.

5 Signs You Work In Earth Observation

Sentinel-2A image of UK south east coastline, acquired on 4th September 2017. Data courtesy of ESA/Copernicus.

Do you recognise yourself in any these five signs? if so, you’re definitely working in the Earth observation industry.

  1. You have a favourite satellite or instrument, or image search tool.
  2. When a satellite image appears on television, you tell everyone in the room which satellite/sensor it came from.
  3. You’ve got an irrational hatred for clouds (unless you’re working on clouds or using radar images).
  4. Anything space related happens and your family asks whether you’re involved with it, and thinks you know everyone who works at NASA or ESA.
  5. Your first reaction to seeing an interesting location isn’t that you should plan to go there. Instead, you wonder whether it would make a good satellite image.

We tick all of these signs at Pixalytics! Last week we suffered from number five when we saw a snippet from the season finale of the UK TV programme ‘Liar’. It wasn’t a programme we’d watched, but as we caught an atmospheric panning shot of the location, and only one thought when through our minds, ‘That would make a great satellite image!’

It was a stunning shot of a marshland with water interwoven between islands. Without knowing anything about the programme, we were expecting it to have been filmed in a far flung Nordic location. Following a bit of impromptu googling we were surprised to discover it was actually Tollesbury on the Essex coast in the UK. It also turns out that we were late to the party on the discovery of the programme and the location.

Sentinel-2A image of Mersea Island and surrounding area, acquired on 4th September 2017. Data courtesy of ESA/Copernicus.

The image on the right shows Mersea Island, which has brown saltmarshes above it within the adjacent inlets of the Blackwater Estuary. To the left of the island is the village of Tollesbury and the Tollesbury marina, which is located within the saltmarshes. This area is the largest of the saltmarshes of Essex, but only the fifth largest of the UK. They play a key role in flood protection and can reduce the height of damaging waves in storm surge conditions by 20%. However, they are disappearing due to sea erosion that’s caused a sixty percent reduction in the last 20 years.

The image itself is a zoomed in pseudo-true-colour composite at 10 m spatial resolution using data acquired by Sentinel-2A on the 4th September 2017 – a surprisingly cloud free day for the UK. The full Sentinel-2 image can be seen at the top of the blog.

As often happens when we look in detail at satellite images, something catches our eye. This time it was the three bluish looking strips just above Mersea island. These are the 82,944 solar panels which make up Langenhoe Solar Farm, and have the capacity to generate 21.15 MW of solar power.

So how many of you recognise our signs of working in Earth observation? Any you think we’ve missed? Get in touch, let us know!

Inspiring the Next Generation of EO Scientists

Artist's rendition of a satellite - 3dsculptor/123RF Stock Photo

Artist’s rendition of a satellite – 3dsculptor/123RF Stock Photo

Last week, whilst Europe’s Earth Observation (EO) community was focussed on the successful launch of Sentinel-5P, over in America Tuesday 10th October was Earth Observation Day!

This annual event is co-ordinated by AmericaView, a non-profit organisation, whose aim to advance the widespread use of remote sensing data and technology through education and outreach, workforce development, applied research, and technology transfer to the public and private sectors.

Earth Observation Day is a Science, Technology, Engineering, and Mathematics (STEM) event celebrating the Landsat mission and its forty-five year archive of imagery. Using satellite imagery provides valuable experience for children in maths and sciences, together with introducing subjects such as land cover, food production, hydrology, habitats, local climate and spatial thinking. The AmericaView website contains a wealth of EO materials available for teachers to use, from fun puzzles and games through to a variety of remote sensing tutorials. Even more impressive is that the event links schools to local scientists in remote sensing and geospatial technologies. These scientists provide support to teachers including giving talks, helping design lessons or being available to answer student’s questions.

This is a fantastic event by AmericaView, supporting by wonderful resources and remote sensing specialists. We first wrote about this three years ago, and thought the UK would benefit from something similar. We still do. The UK Space Agency recently had an opportunity for organisations interested in providing education and outreach activities to support EO, satellite launch programme or the James Webb Space Telescope. It will be interesting to see what the successful candidates come up with.

At Pixalytics we’re passionate about educating and inspiring the next generation of EO scientists. For example, we regularly support the Remote Sensing and Photogrammetry Society’s Wavelength conference for students and early career scientists; and sponsored the Best Early-Career Researcher prize at this year’s GISRUK Conference. We’re also involved with two exciting events at Plymouth’s Marine Biological Association, a Young Marine Biologists (YMB) Summit for 12-18 year olds at the end of this month and their 2018 Postgraduate conference.

Why is this important?
The space industry, and the EO sector, is continuing to grow. According to Euroconsult’s ‘Satellites to Be Built & Launched by 2026 – I know this is another of the expensive reports we highlighted recently – there will be around 3,000 satellites with a mass above 50 kg launched in the next decade – of which around half are anticipated as being used for EO or communication purposes. This almost doubles the number of satellites launched in the last ten years and doesn’t include the increasing number of nano and cubesats going up.

Alongside the number of satellites, technological developments mean that the amount of EO data available is increasing almost exponentially. For example, earlier this month World View successfully completed multi-day flight of its Stratollite™ service, which uses high-altitude balloons coupled with the ability to steer within stratospheric winds. They can carry a variety of sensors, a mega-pixel camera was on the recent flight, offering an alternative vehicle for collecting EO data.

Therefore, we need a future EO workforce who are excited, and inspired, by the possibilities and who will take this data and do fantastic things with it.

To find that workforce we need to shout about our exciting industry and make sure everyone knows about the career opportunities available.

No Paraskevidekatriaphobia For Sentinel-5P!

Sentinel-5P carries the state-of-the-art Tropomi instrument. Image courtesy of ESA/ATG medialab.

On Friday the latest of the Sentinel satellites, Sentinel-5P, is due to be launched at 09.27 GMT from Plesetsk Cosmodrome in Russia.

Friday is the 13th October, and within parts of the western world this is considered to be an unlucky date – although in Italy its Friday 17th which is unlucky and in some Spanish speaking countries it is Tuesday the 13th. Fear of Friday 13th is known as paraskevidekatriaphobia, although evidently it isn’t something Sentinel-5P worries about!

Sentinel-5 Precursor, to give the full title, is dedicated to monitoring our atmosphere. It will create maps of the various trace gases such as nitrogen dioxide, ozone, formaldehyde, sulphur dioxide, methane and carbon monoxide alongside aerosols in our atmosphere. The mission will also support the monitoring of air pollution over cities, volcanic ash, stratospheric ozone and surface UV radiation.

An internal view of the Copernicus Sentinel-5P satellite. Image courtesy of ESA/ATG medialab.

The satellite itself is a hexagonal structure as can be seen in the image to the right. It has three solar wings which will be deployed once the polar sun-synchronous 824 km low earth orbit has been achieved. Sentinel-5P will be orbiting three and half minutes behind NOAA’s Suomi-NPP satellite which carries the Visible/Infrared Imager and Radiometer Suite (VIIRS). This synergy will allow the high resolution cloud mask from VIIRS to be used within the calculations for methane from Sentinel-5P.

Within the hexagonal body the main scientific instrument is the Tropospheric Monitoring Instrument (Tropomi). This is a push-broom imaging spectrometer covering a spectral range from ultraviolet and visible (270–495 nm), near infrared (675–775 nm) and shortwave infrared (2305–2385 nm). The spatial resolution of the instrument will be 7 km x 3.5 km. However, one of the exciting elements of this instrument is that it will have a swath width of 2600 km meaning it can map almost the entire planet every day. It will have full daily surface coverage of radiance and reflectance measurements for latitudes > 7° and < -7°, and better than 95 % coverage for other latitudes.

The key role of Sentinel-5P is to reduce the data gap between the end of the Envisat mission in May 2012 and the launch of Sentinel-5 in 2020. Sentinel-5, and Sentinel-4, will be instruments onboard meteorological satellites operated by Eumetsat and both will be used to monitor the atmosphere.

The timing of Sentinel-5 is interesting for those of within the UK given that almost three quarters of the funding from Copernicus comes from the European Union. By this time Brexit will have occurred and it is currently unclear how that will impact on our future involvement in this programme. This also applies to the work announced at the end of last month to look at an expansion of the Sentinel missions. Invitations to tender (ITT) are due to be issued in the near future, and given our previous blogs on potential limitations and issues, it will be interesting to see which UK companies bid, and whether they will be successful.

Sentinel-5P will help improve our understanding of the processes within the atmosphere which affect our climate, the air we breathe and ultimately the health of everyone on the planet.

Can You See The Great Wall of China From Space?

Area north of Beijing, China, showing the Great Wall of China running through the centre. Image acquired by Sentinel-2 on 27th June 2017. Data courtesy of ESA/Copernicus.

Dating back over two thousand three hundred years, the Great Wall of China winds its way from east to west across the northern part of the country. The current remains were built during Ming Dynasty and have a length of 8 851.8 km according to 2009 work by the Chinese State Administration of Cultural Heritage and National Bureau of Surveying and Mapping Agency. However, if you take into account the different parts of the wall built by other dynasties, its length is almost twenty two thousand kilometres.

The average height of the wall is between six and seven metres, and its width is between four to five metres. This width would allow five horses, or ten men, to walk side by side. The sheer size of the structure has led people to believe that it could be seen from space. This was first described by William Stukeley in 1754, when he wrote in reference to Hadrian’s Wall that ‘This mighty wall of four score miles in length is only exceeded by the Chinese Wall, which makes a considerable figure upon the terrestrial globe, and may be discerned at the Moon.’

Despite Stukeley’s personal opinion not having any scientific basis, it has been repeated many times since. By the time humans began to go into space, it was considered a fact. Unfortunately, astronauts such as Buzz Aldrin, Chris Hatfield and even China’s first astronaut, Yang Liwei, have all confirmed that the Great Wall is not visible from space by the naked eye. Even Pixalytics has got a little involved in this debate. Two years ago we wrote a blog saying that we couldn’t see the wall on Landsat imagery as the spatial resolution was not small enough to be able to distinguish it from its surroundings.

Anyone who is familiar with the QI television series on the BBC will know that they occasionally ask the same question in different shows and give different answers when new information comes to light. This time it’s our turn!

Last week Sam was a speaker at the TEDx One Step Beyond event at the National Space Centre in Leicester – you’ll hear more of that in a week or two. However, in exploring some imagery for the event we looked for the Great Wall of China within Sentinel-2 imagery. And guess what? We found it! In the image at the top, the Great Wall can be seen cutting down the centre from the top left.

Screenshot of SNAP showing area north of Beijing, China. Data acquired by Sentinel-2 on 27th June 2017. Data courtesy of ESA/Copernicus.

It was difficult to spot. The first challenge was getting a cloud free image of northern China, and we only found one covering our area of interest north of Beijing! Despite Sentinel-2 having 10 m spatial resolution for its visible wavelengths, as noted above, the wall is generally narrower. This means it is difficult to see the actual wall itself, but it is possible to see its path on the image. This ability to see very small things from space by their influence on their surroundings is similar to how we are able to spot microscopic phytoplankton blooms. The image on the right is a screenshot from Sentinel Application Platform tool (SNAP) which shows the original Sentinel-2 image of China on the top left and the zoomed section identifying the wall.

So whilst the Great Wall of China might not be visible from space with the naked eye, it is visible from our artificial eyes in the skies, like Sentinel-2.

Evolution of the Earth Observation Market

Artist's rendition of a satellite - 3dsculptor/123RF Stock Photo

Artist’s rendition of a satellite – 3dsculptor/123RF Stock Photo

The changing Earth Observation (EO) market has been a topic of office conversation this week at Pixalytics. We’re currently in the final stage of developing our own product portal, and it was interesting to see that some of our thoughts were echoed by reports from last week’s World Satellite Business Week event in Paris.

Unsurprisingly, speakers at the event agreed that the EO sector has huge growth potential. This is something we regularly see highlighted in various emails and press releases. For example, in the last few weeks we’ve had:

At a few thousand dollars for access to each report, we’ve said before that one of the products we should develop is an annual report on the EO market!

As we’ve been working towards our portal, one of issues we’ve identified is how difficult some portals are to navigate, particularly if you are not an EO expert. This was also recognised at the Paris event, with an acknowledgement that EO companies need to understand what customers want and then provide a user friendly experience to deliver those needs.

As reported by Tereza Pultarova in Space News, there was also discussion on the need to move away from simply selling data, and instead provide answers to the practical questions about the planet that businesses and consumers have. It is only through this transformation that new sectors and markets for EO will open which will be the key for the aforementioned future growth. The Paris event also highlighted some of the key trends that will be the backbone of this transformation:

  • Providing as close as possible to near real time data.
  • Increased data analytics, particularly through machine learning and artificial intelligence platforms to analyse data and highlight anomalies and changes faster.
  • Bringing satellite data together with social media information to rapidly enable context to be added to images.
  • Vertical integration within the industry within satellite firms acquiring with data processing and analytics companies; for example, Digital Globe acquired The Radiant Group earlier this year.
  • Processing data onboard satellites, so users download the information they want, rather than reams of data.

There was a really interesting analogy with the navigation industry given by Wade Larson, president and CEO of Urthecast. He said “Navigation became kind of embedded infrastructure in a much larger industry called location-based services. We think that this is happening with geoanalytics.”

This is the direction of travel for the industry, and some players are moving faster than others. Last week Airbus confirmed their four satellite very high-resolution-imaging constellation, Pléiades Neo, is on schedule for launch in 2020. This will have 30 cm spatial resolution and will utilise the Space Data Highway, also known as the European Data Relay System (EDRS), to stream the images into an online platform. The ERDS uses lasers to transfer up to 40 terabytes a day at a speed of up to 1.8 Gbits per second, meaning users will have access to data in near real time.

This evolution of the EO market needs to be recognised by every company in the industry from the Airbus down to the small company’s trying to launch their own product portal. If you don’t move with the changing market, you won’t get any of the market.