Sentinel To Be Launched

Sentinel-2 Image of Plymouth from 2016. Data courtesy of Copernicus/ESA.

Sentinel-2B was launched at 01:49 GMT on the 7th March from Europe’s Spaceport in French Guiana. It’s the second of a constellation of optical satellites which are part of the European Commission’s Copernicus Programme.

Its partner Sentinel-2A was launched on the 23rd June 2015, and has been providing some stunning imagery over the last eighteen months like the picture of Plymouth above. We’ve also used the data within our own work. Sentinel-2B carries an identical Multispectral Imager (MSI) instrument to its twin with 13 spectral bands:

  • 4 visible and near infrared spectral bands with a spatial resolution of 10 m
  • 6 short wave infrared spectral bands with a spatial resolution of 20 m
  • 3 atmospheric correction bands with a spatial resolution of 60 m

With a swath width of 290 km the constellation will acquire data in a band of latitude extending from 56° South around Isla Hornos, Cape Horn, South America to 83° North above Greenland, together with observations over specific calibration sites, such as Dome-C in Antarctica. Its focus will be on continental land surfaces, all European islands, islands bigger than 100 square kilometres, land locked seas and coastal waters.

The satellites will orbit 180 degrees apart at an altitude of 786 km, which means that together they will revisit the same point on Earth every five days at the equator, and it may be faster for parts of southern Europe. In comparison, Landsat takes sixteen days to revisit the same point.

With all Copernicus data being made freely available to anyone, the short revisit time offers opportunities small and micro Earth Observation businesses to establish monitoring products and services without the need for significant investment in satellite data paving the way for innovative new solutions to the way in which certain aspects of the environment are managed. Clearly, five day revisits are not ‘real-time’ and the spatial resolution of Sentinel data won’t be suitable for every problem.There is joint work between the US and Europe, to have complementarity with Landsat-8, which has thermal bands, and allows a further opportunity for cloud-free data acquisitions. Also, commercial operators provide higher spatial resolution data.

At Pixalytics we’re supporters of open source in both software and imagery. Our first point of call with any client is to ask whether the solution can be delivered through free to access imagery, as this can make a significant cost saving and allow large archives to be accessed. Of course, for a variety of reasons, it becomes necessary to purchase imagery to ensure the client gets the best solution for their needs. Of course, applications often include a combination of free to access and paid for data.

Next’s week launch offers new opportunities for downstream developers and we’ll be interested to see how we can exploit this new resource to develop our products and services.

Will Earth Observation’s power base shift in 2017?

Blue Marble image of the Earth taken by the crew of Apollo 17 on Dec. 7 1972. Image Credit: NASA

Blue Marble image of the Earth taken by the crew of Apollo 17 on Dec. 7 1972.
Image Credit: NASA

We’re only a few days into 2017, but this year may see the start of a seismic shift in the Earth Observation (EO) power base.

We’ve previously described how the sustainable EO industry really began this week thirty nine years ago. On 6th January 1978 NASA deactivated Landsat-1; it had already launched Landsat-2, carrying the same sensors, three years earlier and with guaranteed data continuity our industry effectively began.

Since then the USA, though the data collected by NASA and NOAA satellites, has led the EO global community. This position was cemented in 2008 when it made all Landsat data held by the United States Geological Survey (USGS) freely available, via the internet, to anyone in the world. This gave scientists three decades worth of data to start investigating how the planet had changed, and companies sprang up offering services based entirely on Landsat data. This model of making data freely available has been so transformational, that the European Union decided to follow it with its Copernicus Programme.

Landsat-1 and 2 were followed by 4, 5, 7 & 8 – sadly Landsat 6 never made its orbit – and Landsat 9 is planned for launch in 2020. The USA’s role EO leadership has never been in question, until now.

US President-elect Donald Trump and his team have already made a number of statements indicating that they intended to cut back on NASA’s Earth Science activities. There are a variety of rumours suggesting reasons for this change of approach. However, irrespective of the reason, slashing the current $2 billion Earth Science budget will have huge consequences. Whilst all of this is just conjecture at the moment, the reality will be seen after 20th January.

Against this America backdrop sits the Copernicus Programme, with the European Space Agency due to launch another three satellites this year:

  • Sentinel 2B is planned for March. This is the second of the twin constellation optical satellites offering a spatial resolution of 10 m for the visible bands. The constellation will revisit the same spot over the equator every five days, with a shorter temporal resolution for higher latitudes.
  • June is the scheduled month for the launch of the Sentinel 5 Precursor EO satellite to measure air quality, ozone, pollution and aerosols in the Earth’s atmosphere. This will be used to reduce the data gaps between Envisat, which ended in 2012, and the launch of Sentinel-5.
  • Sentinel 3B is due to launched in the middle of the year, and like 2B is the second in a twin satellite constellation. This pair is mainly focussed on the oceans and measure sea surface topography, sea and land surface temperature, and ocean and land colour. It will provide global coverage every two days with Sea and Land Surface Temperature Radiometer (SLSTR) and the Ocean and Land Colour Instrument (OLCI).

These launches will take give the Copernicus programme seven satellites collecting a wide variety of optical and radar data across the entire planet, which is then made freely available to anyone. It’s obvious to see what will fill any vacuum created by a reduction in Earth Science in the USA.

Depending on how much of the next US President’s rhetoric is turned into action, we may start to see the shift of the EO power base to Europe. Certainly going to be an interesting year ahead!

Space Strategy For Europe

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

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

A Space Strategy for Europe was issued last week by the European Commission (EC), based around four strategic goals.

  • Maximising the Benefits of Space for Society and the European Union (EU) Economy
  • Fostering a Globally Competitive & Innovative European Space Sector
  • Reinforcing Europe’s Autonomy In Accessing & Using Space In a Secure & Safe Environment
  • Strengthening Europe’s Role as a Global Actor & Promoting International Co-operation

The strategy began with a heartening assessment of the European space economy, recognising that it supports almost a quarter of million jobs and is valued at around €50 bn.

The Earth observation (EO) sector is strongly represented within the document, particularly in the first two goals. Whilst some of the references to EO are fairly obvious statements, there are also some intriguing comments.

Maximising the Benefits of Space for Society and the EU Economy
This goal identifies a significant untapped potential for the uptake of space services and data, and outlines a number of actions that will be taken to unlock this; including:

  • Encouraging the use of space services and data, wherever they provide effective solutions – the last part provides an interesting test.
  • Ensuring EU legislation will be supportive of the uptake of these services.
  • Provision of improved access to, and exploitation of, Copernicus data – anyone who has tried to access data will know the need for continued improvement.Improving interconnectivity with other data infrastructures and other datasets.
  • Define clear limits between free Copernicus core information services and commercial applications – hopefully this will show Copernicus services as an opportunity rather than a threat; something that is currently unclear for, particularly SME, businesses.

Overall, the strategy states this will open up new business opportunities, including for SME’s and start-ups. We’re supportive of these actions, however we also have concerns.

The document has a single line stating it will reach out to new users and connect downstream activities to non-space sectors. This is the holy grail for every EO commercial organisation, and very few have come close to achieving it. The minimal statement potentially suggests the EC is fundamentally underestimating how difficult this will be.

An intriguing element is the intention “to introduce an ‘industry test’ to check downstream suppliers can provide reliable and affordable services.” We’d support any quality accreditation, but it will be interesting to see whether this is a certification scheme for everyone or a barrier to market for SMEs and start-ups.

This issue was strongly debated at a European Space Agency (ESA) meeting last week, particularly over the question as to whether the accrediting body assumes liability when a service doesn’t deliver. It is worth noting that the European Association of Remote Sensing Companies (EARSC) has an existing certification scheme for management practices, but only a few organisations have gone through the process to date.

Fostering a Globally Competitive & Innovative European Space Sector
This goal focuses on supporting research and development within the space economy, together with promoting entrepreneurship and business opportunities.

It specifically references the launch of a dedicated sector skills alliance for space/Earth observation – which sounds great. However, it appears to be a committee of stakeholders to discuss the necessary skills requirements for the industry, and so it is not clear what it will actually do.

The Commission also aims to support space entrepreneurs, start-ups and SME’s through a variety of programmes, dialogues and synergies! Lots of good words used with little clarity of real action.

Reinforcing Europe’s Autonomy In Accessing & Using Space In a Secure & Safe Environment
This goal has a focus on ensuring that Europe has the infrastructure and capacity to operate in space freely; although this does seem slightly at odds with the international co-operation trumpeted in the final goal.

However, the most interesting element for the EO community is the statement that the radio frequency spectrum must be protected from interference from other systems. This is something that is vital for space sector, but falls short of guaranteeing space technology having access to radio frequencies. In recent times, there has been a threat to the microwave frequencies from the requirements of mobile phone and wifi networks.

Strengthening Europe’s Role as a Global Actor & Promoting International Co-operation
The final strategic goal highlights the importance of international co-operation and the desire for the EU to have a much greater global lead. Given that the EU has the second largest public space budget in the world, this emphasis is welcomed.

It also notes that the EU will contribute to initiatives including the Global Earth Observation System of Systems (GEOSS) and the Committee on Earth Observation Satellites (CEOS).

Summary
Like all strategies there are lots of good intentions within these words, but limited practical details. It won’t be until the detailed plans are draw up to implement these actions that we will be able to determine whether this document is a valuable step forward for the space economy in Europe, or a thirteen page missed opportunity.

Our Footnote for the UK
The strategy makes clear the EU & ESA will be key to the delivery of this strategy, and so we can’t comment without mentioning the Brexit word. The current plan is that the UK will be out of the EU in early 2019, and therefore the UK Government’s input to the upcoming ESA ministerial is absolutely critical, alongside decisions on how we’ll interact with the Copernicus program.

We need to give a strong and positive commitment to our ongoing involvement with ESA, without this the UK’s space economy will face a significant setback. Everyone within the community must ensure that the Government, and Ministers, are fully aware of the importance of this in the coming weeks.

Rio Olympics from space

Rio de Janeiro, Brazil, acquired on the 13th July 2016. Image courtesy of Copernicus/ESA.

Rio de Janeiro, Brazil, acquired on the 13th July 2016. Image courtesy of Copernicus/ESA.

The Opening Ceremony of the 2016 Summer Olympics takes place on Friday and so we’ve decided to revive our highly infrequent blog series ‘Can you see sporting venues from space?’ Previously we’ve looked for the Singapore and Abu Dhabi Formula One Grand Prix Circuits, but this week we’re focussing on the Rio Olympic venues.

Rio de Janeiro
The Games of the XXXI Olympiad will take place from the 5th to the 21st August in the Brazilian city of Rio de Janeiro. It is expected that more than ten thousand athletes will be competing for the 306 Olympic titles across 37 venues, 7 of which are temporary venues and 5 are outside Rio. The remaining twenty-five are permanent venues within the city, and 11 have been newly built for the Olympics and Paralympics. It is these permanent venues that we’ll see if we can spot from space!

The image at the top of the blog shows the Rio area, and you’ll notice the dark green area in the centre of the image which is the Tijuca National Park containing one of the world’s largest urban rainforest. It covers an area of 32 km².

Spatial Resolution
Spatial resolution is the key characteristic in whether sporting venues can be seen from space, and in simplistic terms it refers to the smallest object that can be seen on Earth from that sensor. For example, an instrument with a 10 m spatial resolution means that each pixel on its image represents 10 m, and therefore for something to be distinguishable on that image it needs to be larger than 10 m in size. There are exceptions to this rule, such as gas flares, which are so bright that they can dominate a much larger pixel.

We used the phrase ‘simplistic terms’ above because technically, the sensor in the satellite doesn’t actually see a square pixel, instead it sees an ellipse due to the angle through which it receives the signal. The ellipses are turned into square pixels by data processing to create the image. Spatial resolution is generally considered to have four categories:

  • Low spatial resolution: tend to have pixels between 50 m and 1 km.
  • Medium spatial resolution: tend to have pixels between 4 m and 50 m.
  • High spatial resolution: tend to have pixels between 1 m and 4 m.
  • Very high spatial resolution: tend to have pixels between 0.25 m to 1 m

Clearly with very high resolution imagery, such as that provided by commercial Worldview satellites owned by DigitalGlobe, can provide great images of the Olympic venues. However, as you know we like to work with data that is free-to-access, rather than paid for data. We’ve used Sentinel-2 data for this blog, which has a 10 m spatial resolution for its visible and near infra-red bands via the multispectral imager it carries.

Can we see the Olympic venues from space?
In our earlier parts of this infrequent series we couldn’t see the night race from the Singapore circuit, but we did identify the Abu Dhabi track and red roof of the Ferrari World theme park. So can we see the Olympics? Actually we can!

Image courtesy of Copernicus/ESA.

Image courtesy of Copernicus/ESA.

On the image to left, you’ll notice two bright white circles, one in the middle of the image and the second to the south-east. The bright circle in the middle is the Olympic Stadium which will be hosting the athletics and stands out clearly from the buildings surrounding it, to the South East is the Maracanã Stadium which will stage the opening and closing ceremonies together with the finals of the football tournaments.

Image courtesy of Copernicus/ESA.

Image courtesy of Copernicus/ESA.

In the bottom left of the image is small triangular shape which is location for the Aquatics Stadium, Olympic Tennis Centre, the Gymnastic and Wheelchair basketball arena, and the Carioca arenas which will host basketball, judo, wrestling and boccia. The bottom of the triangle juts out into the Jacarepagua Lagoon.

Image courtesy of Copernicus/ESA.

Image courtesy of Copernicus/ESA.

In the top left of the image, you can see the runway of the military Afonsos Air Force Base and north of the air base are a number of other Olympic venues, however these are hard to spot within their surroundings – these include the Equestrian Centre, Hockey Centre, BMX Centre, Whitewater canoe slalom course and the Deodoro stadium which will host the Rugby 7s and modern pentathlon.

It is possible to see the Olympic venues from space! Good luck to all the athletics competing over the next few weeks.

Brexit and the Earth Observation Market

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

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

Last week the UK voted to leave the European Union (EU). For us it was sad day, evidenced by the fact that on voting day Sam was at the European Association of Remote Sensing Laboratories (EARSeL) Symposium in Bonn, Germany; and I was in Brussels having attended the European Association of Remote Sensing Companies (EARSC) Annual General Meeting the day before – I should say we had both already submitted our postal votes!

This obvious topic for this week is what Brexit means for the UK Space Market, and in turn what it means for us:

European Space Agency (ESA)
ESA is not the EU. It has a different membership and different rules. The UK can remain part of ESA even if it leaves the EU, as evidenced by Norway and Switzerland’s membership, and even Canada’s associate membership.

However, at the ESA Ministerial in December member countries will need to declare how much money they intended to contribute towards ESA programmes. ESA operates a geo-return principle which dictates that countries cannot receive more money back than they put in, and therefore the decision on how much funding to commit at the December meeting will be vital for the UK Space Industry.

At the moment there is a power vacuum in this country following the resignation of the Prime Minister, and it would appear that no major decisions will be made on the future direction of the country until the new Prime Minister is appointed in September. Given the new Prime Minister will want to set up his own Executive arrangements and that the most pressing matter will be Brexit, it is not clear who will be taking the significant decision on the UK’s ESA Contribution.

Lack of commitment at this point has the potential to damage the UK Space Industry far more than Brexit.

European Union
Despite the assertion above that the EU and ESA are different bodies, they are linked organisations. They have a joint European Space Strategy and the EU is the biggest financial contributor to ESA’s budget. In addition, the EU owns a number of programmes such as Copernicus and the Galileo positioning, navigation & timing network.

Outside the EU the UK will probably no longer have a voice within these programmes and it is unlikely the siting of significant infrastructure related to these programmes, such as ground segments, will include this country. Hence, even remaining an active participant within ESA, it is hard to argue against the fact that the UK’s role in the future of the European space industry will diminish.

Single Market
The space industry, like other industries, currently benefits from the single market which makes it easier for European businesses to trade with each other. It is clear that most of our businesses, and politicians, feel that this is a benefit they’d like to keep. The question is whether they will be willing to pay the EU’s price?

If they do, then it is likely that change will be limited. However, if they don’t and the UK leaves the Single Market then trade with Europe will become more difficult. It will of course continue, but there may be tariffs, limitations on exports/imports and the potential for businesses to open or close offices within the UK or Europe to best maintain their access to both the UK and European markets.

Scientific Collaboration
We collaborate with a lot of EU companies, scientists and students. Now again there is no suggestion that this would stop, but everything will become more complicated.

  • How easy and quickly will people be able to get visa to travel to Europe or vice versa? This could impact attendance at meetings or conferences.
  • Will European Conferences still come to the UK?
  • What will be the impact on placement programmes such as ERASMUS? ERASMUS has different membership to the EU, like ESA, but will the UK still be as attractive to those students?

Of real scientific concern is the emerging anecdotal evidence that UK researchers are being removed from EU based funding bids, such as Horizon 2020, as the consortia fear their bids will be less attractive if the UK is involved. If true, this is will impact scientific research, at least in the short term until our involved in such programmes is clarified.

UK Space Industry
The UK has an expanding, exciting and innovative space industry and the future is certainly not dependant on us being part of the EU. However, it would be naïve to suggest that we don’t face challenges ahead following Brexit. There are a number of key elements we need in place to ensure that our industry can continue to thrive:

  1. Commitment to our continued membership of ESA, supported by funding at the December ministerial.
  2. Commitment that the resources the UK Science and Space sectors received via EU funding, such as Horizon 2020, must be replaced with equivalent UK based funding calls.
  3. Not to let the Brexit negotiations overtake everything else. For example, it must not stop continuing progress on elements such as a UK Spaceport.

Pixalytics
We have a variety of strong European links including:

  • European contracts
  • Scientific collaboration with European Researchers/Institutes
  • European placement students spending time working with us
  • Contracts that are either directly, or indirectly, based on ESA funding
  • Membership of European Associations

We believe we have a strong business, with good value products and a positive brand. However, like all other UK businesses, we are going to need to assess our current business strategy, and decisions we need to make, through the prism of Brexit as further information is known.

Conclusion
Almost one week on from the UK vote, I think our position is best summed up by paraphrasing the famous statement of US Secretary of Defense, Donald Rumsfeld:

There are some things we do not know, but there are also things we don’t know we don’t know and those will be the difficult ones.

Or to put it more succinctly, we face months, and years, of uncertainty! What does everyone else think?

Monitoring ocean acidification from space

Enhanced pseudo-true colour composite of the United Kingdom showing coccolithophore blooms in light blue. Image acquired by MODIS-Aqua on 24th May 2016. Data courtesy of NASA.

Enhanced pseudo-true colour composite of the United Kingdom showing coccolithophore blooms in light blue. Image acquired by MODIS-Aqua on 24th May 2016. Data courtesy of NASA.

What is ocean acidification?
Since the industrial revolution the oceans have absorbed approximately 50% of the CO2 produced by human activities (The Royal Society, 2005). Scientists previously saw this oceanic absorption as advantageous, however ocean observations in recent decades have shown it has caused a profound change in the ocean chemistry – resulting in ocean acidification (OA); as CO2 dissolves into the oceans it forms carbonic acid, lowering the pH and moving the oceans into a more acidic state. According to the National Oceanic Atmospheric Administration (NOAA) ocean pH has already decreased by about 30% and some studies suggest that if no changes are made, by 2100, ocean pH will decrease by 150%.

Impacts of OA
It’s anticipated OA will impact many marine species. For example, it’s expected it will have a harmful effect on some calcifying species such as corals, oysters, crustaceans, and calcareous plankton e.g. coccolithophores.

OA can significantly reduce the ability of reef-building corals to produce their skeletons and can cause the dissolution of oyster’s and crustacean’s protective shells, making them more susceptible to predation and death. This in turn would affect the entire food web, the wider environment and would have many socio-economic impacts.

Calcifying phytoplankton, such as coccolithophores, are thought to be especially vulnerable to OA. They are the most abundant type of calcifying phytoplankton in the ocean, and are important for the global biogeochemical cycling of carbon and are the base of many marine food webs. It’s projected that OA may disrupt the formation and/or dissolution of coccolithophores, calcium carbonate (CaCO3) shells, impacting future populations. Thus, changes in their abundance due to OA could have far-reaching effects.

Unlike other phytoplankton, coccolithophores are highly effective light scatterers relative to their surroundings due to their production of highly reflective calcium carbonate plates. This allows them to be easily seen on satellite imagery. The figure at the top of this page shows multiple coccolithophore blooms, in light blue, off the coast of the United Kingdom on 24th March 2016.

Current OA monitoring methods
Presently, the monitoring of OA and its effects are predominantly carried out by in situ observations from ships and moorings using buoys and wave gliders for example. Although vital, in situ data is notoriously spatially sparse as it is difficult to take measurements in certain areas of the world, especially in hostile regions (e.g. Polar Oceans). On their own they do not provide a comprehensive and cost-effective way to monitor OA globally. Consequently, this has driven the development of satellite-based sensors.

How can OA be monitored from space?
Although it is difficult to directly monitor changes in ocean pH using remote sensing, satellites can measure sea surface temperature and salinity (SST & SSS) and surface chlorophyll-a, from which ocean pH can be estimated using empirical relationships derived from in situ data. Although surface measurements may not be representative of deeper biological processes, surface observations are important for OA because the change in pH occurs at the surface first.

In 2015 researchers at the University of Exeter, UK became the first scientists to use remote sensing to develop a worldwide map of the ocean’s acidity using satellite imagery from the European Space Agency’s Soil Moisture and Ocean Salinity (SMOS) satellite that was launched in 2009 and NASA’s Aquarius satellite that was launched in 2011; both are still currently in operation. Thermal mounted sensors on the satellites measure the SST while the microwave sensors measure SSS; there are also microwave SST sensors, but they have a coarse spatial resolution.

Future Opportunities – The Copernicus Program
The European Union’s Copernicus Programme is in the process of launching a series of satellites, known as Sentinel satellites, which will improve understanding of large scale global dynamics and climate change. Of all the Sentinel satellite types, Sentinels 2 and 3 are most appropriate for assessment of the marine carbonate system. The Sentinel-3 satellite was launched in February this year andwill be mainly focussing on ocean measurements, including SST, ocean colour and chlorophyll-a.

Overall, OA is a relatively new field of research, with most of the studies being conducted over the last decade. It’s certain that remote sensing will have an exciting and important role to play in the future monitoring of this issue and its effects on the marine environment.

Blog written by Charlie Leaman, BSc, University of Bath during work placement at Pixalytics.

Is the remote sensing market an urban legend?

Yeti footprints

Yeti footprints on ice – erectus/123RF Stock Photo

The remote sensing/Earth observation (EO) market is like the Yeti or the Loch Ness Monster – there are plenty of people out there who tell you it exists, but very few companies have seen it with their own eyes!

We work in a fast growing and expanding industry, at least according to the myriad of reports that regularly drop into our inboxes. For example, over the last few weeks we’ve had press releases such as :-

With all this growth everything in the remote sensing/EO industry is fantastic, right? Well, no actually! Despite the report announcements, lots of companies within the industry are struggling to locate this valuable market.

Historically, a lot of funding was provided by governments and space agencies in the form of grants or tenders to promote the use, and uptake, of EO data, which enabled companies to develop and grow. Whilst such sources of funding are still available; the maturing of the industry coupled with the global economic slowdown is starting to constrict this revenue stream, forcing more and more EO companies out in the commercial world looking for the fabled billion dollar market. This development is currently being supported by venture capital as the growth forecasts are encouraging investment, but how many of these companies will be able to transition into profit making businesses?

The Holy Grail for everyone is a reliable, consistent and expanding market for EO products and services, something that few businesses in our sector have successfully found. There are a variety of reasons why the market feels like an urban legend, including:

  • Lack of knowledge on the products wanted leading to supplier led, rather than consumer led, product development.
  • Lack of an existing market meaning that EO companies need to work hard on advertising to tell possible customers they exist and the benefits they can offer.
  • Monopolistic behaviour of governments/space agencies. These bodies have spent large sums to launch satellites and need to demonstrate value for money. For example, the European Commission’s Copernicus Programme recently announced its intention to develop agriculture products from Sentinel data. Rather than developing the market, this could potentially destroy the market for existing EO companies.

It’s clear that to get proof of a remote sensing/EO market, companies need to develop value for money products that customers want, demonstrate the benefits of satellite data as an information source and stand out from the other legend hunters!

Here at Pixalytics we’re in the process of packing our data, securing our satellite links and checking our geo-referenced maps, ready to set out onto our journey in search of the fabled market. To date, our businesses has focussed on bespoke specialised products for individual customers and now we’re also hoping to develop more standard products that can be processed on demand, or made available from a pre-processed archive.

Of course we don’t have all the answers of where to find the customers, what the right products are or the best way of making letting people know we exist and we can help them. Although having seen the cost of these industry reports, we’re starting to think that writing, and selling, remote sensing/EO market reports is where the real money is!

Over the next few months, we’ll use this blog to tell you about our journey, the mistakes we make and what we learn. As we get a glimpses into the market we’ll put it up here, although it might be grainy and indistinguishable – but then aren’t all urban legend pictures!

The cost of ‘free data’

False Colour Composite of the Black Rock Desert, Nevada, USA.  Image acquired on 6th April 2016. Data courtesy of NASA/JPL-Caltech, from the Aster Volcano Archive (AVA).

False Colour Composite of the Black Rock Desert, Nevada, USA. Image acquired on 6th April 2016. Data courtesy of NASA/JPL-Caltech, from the Aster Volcano Archive (AVA).

Last week, the US and Japan announced free public access to the archive of nearly 3 million images taken by ASTER instrument; previously this data had only been accessible with a nominal fee.

ASTER, Advanced Spaceborne Thermal Emission and Reflection Radiometer, is a joint Japan-US instrument aboard NASA’s Terra satellite with the data used to create detailed maps of land surface temperature, reflectance, and elevation. When NASA made the Landsat archive freely available in 2008, an explosion in usage occurred. Will the same happen to ASTER?

As a remote sensing advocate I want many more people to be using satellite data, and I support any initiative that contributes to this goal. Public satellite data archives such as Landsat, are often referred to as ‘free data’. This phrase is unhelpful, and I prefer the term ‘free to access’. This is because ‘free data’ isn’t free, as someone has already paid to get the satellites into orbit, download the data from the instruments and then provide the websites for making this data available. So, who has paid for it? To be honest, it’s you and me!

To be accurate, these missions are generally funded by the tax payers of the country who put the satellite up. For example:

  • ASTER was funded by the American and Japanese public
  • Landsat is funded by the American public
  • The Sentinel satellites, under the Copernicus missions, are funded by the European public.

In addition to making basic data available, missions often also create a series of products derived from the raw data. This is achieved either by commercial companies being paid grants to create these products, which can then be offered as free to access datasets, or alternatively the companies develop the products themselves and then charge users to access to them.

‘Free data’ also creates user expectations, which may be unrealistic. Whenever a potential client comes to us, there is always a discussion on which data source to use. Pixalytics is a data independent company, and we suggest the best data to suit the client’s needs. However, this isn’t always the free to access datasets! There are a number of physical and operating criteria that need to be considered:

  • Spectral wavebands / frequency bands – wavelengths for optical instruments and frequencies for radar instruments, which determine what can be detected.
  • Spatial resolution: the size of the smallest objects that can be ‘seen’.
  • Revisit times: how often are you likely to get a new image – important if you’re interested in several acquisitions that are close together.
  • Long term archives of data: very useful if you want to look back in time.
  • Availability, for example, delivery schedule and ordering requirement.

We don’t want any client to pay for something they don’t need, but sometimes commercial data is the best solution. As the cost of this data can range from a few hundred to thousand pounds, this can be a challenging conversation with all the promotion of ‘free data’.

So, what’s the summary here?

If you’re analysing large amounts of data, e.g. for a time-series or large geographical areas, then free to access public data is a good choice as buying hundreds of images would often get very expensive and the higher spatial resolution isn’t always needed. However, if you want a specific acquisition over a specific location at high spatial resolution then the commercial missions come into their own.

Just remember, no satellite data is truly free!

Satellite Data Continuity: Hero or Achilles Heel?

Average thickness of Arctic sea ice in spring as measured by CryoSat between 2010 and 2015. Image courtesy of ESA/CPOM

Average thickness of Arctic sea ice in spring as measured by CryoSat between 2010 and 2015. Image courtesy of ESA/CPOM

One of satellite remote sensing’s greatest strengths is the archive of historical data available, allowing researchers to analyse how areas change over years or even decades – for example, Landsat data has a forty year archive. It is one of the unique aspects of satellite data, which is very difficult to replicate by other measurement methods.

However, this unique selling point is also proving an Achilles Heel to industry as well, as highlighted last week, when a group of 179 researchers issued a plea to the European Commission (EC) and the European Space Agency (ESA) to provide a replacement for the aging Cryosat-2 satellite.

Cryosat-2 was launched in 2010, after the original Cryosat was lost during a launch failure in 2005, and is dedicated to the measurement of polar ice. It has a non sun-synchronous low earth orbit of just over 700 km with a 369 day ground track cycle, although it does image the same areas on Earth every 30 days. It was originally designed as three and half year mission, but is still going after six years. Although, technically it has enough fuel to last at least another five years, the risk of component failure is such that researchers are concerned that it could cease to function at any time

The main instrument onboard is a Synthetic Aperture Interferometric Radar Altimeter (SIRAL) operating in the Ku Band. It has two antennas that form an interferometer, and operates by sending out bursts of pulses at intervals of only 50 microseconds with the returning echoes correlated as a single measurement; whereas conventional altimeters send out single pulses and wait for the echo to return before sending out another pulse. This allows it to measure the difference in height between floating ice and seawater to an accuracy of 1.3cm, which is critical to measurement of edges of ice sheets.

SIRAL has been very successful and has offered a number of valuable datasets including the first complete assessment of Arctic sea-ice thickness, and measurements of the ice sheets covering Antarctica and Greenland. However, these datasets are simply snapshots in time. Scientists want to continue these measurements in the coming years to improve our understanding of how sea-ice and ice sheets are changing.

It’s unlikely ESA will provide a follow on satellite, as their aim is to develop new technology and not data continuity missions. This was part of the reason why the EU Copernicus programme of Sentinel satellites was established, whose aim is to provide reliable and up to date information on how our planet and climate is changing. The recently launched Sentinel-3 satellite can undertake some of the measurements of Cryosat-2, it is not a replacement.

Whether the appeal for a Cryosat-3 will be heard is unclear, but what is clear is thought needs to be given to data continuity with every mission. Once useful data is made available, there will be a desire for a dataset to be continued and developed.

This returns us to the title of the blog. Is data continuity the hero or Achilles Heel for the satellite remote sensing community?

Supercharging Satellite Data

Impression of EDRS high-speed feeder link relays to Europe. Image courtesy of ESA.

Impression of EDRS high-speed feeder link relays to Europe. Image courtesy of ESA.

Satellite remote sensing is set for a speed turbo boost with the launch of the less than snappily named EDRS. The first node of the European Data Relay System (EDRS), which is effectively a space based satellite data super highway, was launched last Saturday.

Most satellites send data back to Earth only as they pass over ground receiving stations. In addition, they have an orbital track that takes them across the entire planet, travelling at speeds of around 7 000 miles per hour, which means they are only in range of a single receiving station for approximately 10 minutes of each orbit. Given the size of Earth observation (EO) datasets, there are limits to the speed EO data can be sent back from space and it becomes increasingly difficult to download the full amount of data that can be collected. This is partially offset by having a network of ground receiving stations across the world. For example, Landsat has an international ground station (IGS) Network that includes three stations in the USA alongside 15 in other countries across the world.

The EDRS works in a different way. It is based in a much higher orbit than many EO satellites, an orbit called geostationary, which means that the satellite remains above the same place on Earth at all times and thus is in constant contact with its ground station. ERDS collects data from EO satellites by laser, and can stay in contact with the satellites for a much longer period because of its higher height. Once the EDRS has received the data, it immediately relays the data to its ground station.

EDRS-A was launched by piggybacking the Eutelsat 9B satellite, whilst a second satellite, curiously called EDRS-C, is due to launch in 2017. The International Space Station will also be connected up in 2018, and a third satellite is planned for launch in 2020 and will sit over the Asia-Pacific region. It will require further satellites to provide twenty-four hour all orbit data relay coverage.

After a significant testing phase, EDRS is expected to go into service this summer. The European Commission’s Copernicus Programme will be the first major customer, relaying data from its Sentinel satellites.

Once fully operational the system will be capable of relaying up to 50 terabytes of data each day at speeds of up to 1.8 gigabits per second, which is about 90 to 100 times faster than a typical internet connection.

This will dramatically improve access to time-critical data, and will benefit a variety of applications including:

  • Rescue and disaster relief teams that need EO data to focus and support their work.
  • Monitoring fast moving environmental issues such as forest fires, floods, pollution incidents and sea ice zones.
  • Government and security services that could utilise real time data to support their aircraft and unmanned aerial observation vehicles.
  • Monitoring of illegal fishing or piracy events.

EDRS will certainly supercharge EO and remote sensing, offering new opportunities for the provision of near real time applications to a variety of users.