Looking Deeper At Phytoplankton from Space

NASA is currently in the middle of a joint airborne and sea campaign to study the ocean and atmosphere in preparation for developing instruments for future spaceborne missions. The Ship-Aircraft Bio-Optical Research (SABOR) campaign has brought together experts from a variety of disciples to focus on the issue of the polarization of light in the ocean; it runs from 17th July to 7th August and will co-ordinate ocean measurements with overflights.

One of the instruments on SABOR is an airborne Lidar-Polarimeter aimed at overcoming the limitation of vertically integrated surface measurements as captured by many existing Earth Observation satellites. These traditional satellites measure the water-leaving radiance, which is the signal returned from an area of water; the problem is that the signal is returned from a variety of different depths and it’s then aggregated to provide a single vertically integrated measurement for that area.

Diffuse attenuation depth at 490 nm, Kd(490), created from the SeaWiFS mission climatological data; data products retrieved from http://oceancolor.gsfc.nasa.gov/

Diffuse attenuation depth at 490 nm, Kd(490), created from the SeaWiFS mission climatological data; data products retrieved from http://oceancolor.gsfc.nasa.gov/

In effect, this means that a phytoplankon bloom at the surface will show up as a strong concentration on an image, however the same bloom at a deeper depth will show as having lower concentrations. The figure on the right shows the diffuse attenuation depth at 490 nm, blue light, created from the SeaWiFS mission climatological data collected between 1997 and 2010; the higher the value the shallower the depth of maximum passive light penetration. So, in summary, the light penetrates further within the open ocean than in many coastal waters that are more turbid.

The SABOR Lidar is based on lasers and will provide depth-resolved profiles, so instead of having a single value for an area of water, the measurements will be separable for different depths; expected to penetrate to around 50m. This will enable a much more detailed analysis of what’s happening within the water column. Satellite Lidar measurements have already been used to provide initial insights into the scattering of light resulting from phytoplankton through the CALIPSO satellite, an atmospheric focused Lidar mission launched in 2006.

In addition, the polarimeter element of SABOR will improve the quantification of the in-water constituents, such as the concentration of Chlorophyll-a (the primary pigment in most phytoplankton as well as land based plants) plus an understanding of the marine aerosols and clouds. Polarimeters have been launched before with the POLDER/PARASOL missions being examples.

The SABOR campaign will provide valuable information to support a proposal to have an Ocean Profiling Atmospheric Lidar (OPAL) deployed from the International Space Station (ISS) in 2015. If successful, it will join the existing Earth Observation mission on the ISS, called the Hyperspectral Imager for the Coastal Ocean (HICO), which I discussed in an earlier blog.

The potential offered by depth profiled oceanic measurements is exciting and will offer much more granularity beyond the ocean’s surface. I’m looking forward to the campaign’s results.

Random Numbers from Space

The concept of randomness, and creation of random numbers, has been part of human culture for thousands of years; in fifth century Athens, they considered elections undemocratic, everyone was considered equal and they selected people at random from the population to serve as the government. Perhaps our current politicians should take note, although the principle itself still exists in the UK through jury duty selection.

Random numbers are integral to modern society, from the obvious betting and gambling arenas, to sport, science, the arts and cryptography – all those little devices used to log into bank accounts are based on random numbers; in addition, they’re key to satellite communication systems.

Computerised random number generators have been around as long as programmers have programmed, and their algorithms produce a series of numbers that look random, but in fact they aren’t as they have a predetermined sequence. These are known as pseudo random numbers and are fine for many uses, but aren’t suitable to applications like secure communications or cryptography; for these we need to create true random numbers.

Lightning, Copyright: Taiga / 123RF Stock Photo

Lightning, Copyright: Taiga / 123RF Stock Photo

A true random number is one whose outcome is unpredictable, for example rolling a dice. Whilst this works for a single true random number, what if you want thousands or millions? Building a machine to throw millions of dice simultaneously isn’t sensible, instead random numbers are created using a physical property of the environment applied through a computer, for example decays in radioactive sources, snapshots of lava lamps or atmospheric noise caused by lightning strikes within thunderstorms. Last Thursday night would have been a goldmine to anyone using this methodology, as over 3,000 lightning strikes hit the country within three hours.

The space sector is now becoming involved in this area. In last week’s blog we reported on the two UK satellites recently launched; the UKube-1, built by Clyde Space in Glasgow, carries a true random number generator. The JANUS experiment will test the feasibility of using cosmic radiation to create true random numbers by detecting impacts from space particles through the single event upset effect methodology.

This could offer an alternative method of creating high volumes of random numbers for the communication and cryptography industries particularly, and gives one more way in which space can help.

Blog written in conjunction with Adam Mrozek, work placement student.

How Many Earth Observation Satellites are in Space?

Space is growing market! With Google recently announcing its purchase of Skybox Imaging, the myriad of organisations jostling to be the first to offer commercial space flights and the launch of two UK satellites last week(TechDemoSat-1 and UKube-1) it’s clear that space is becoming an increasingly congested market place.

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

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

Have you ever wondered about the Earth Observation (EO) market? Who owns and controls the EO satellites you use? I’m sure you know the big names such as the US Government controlling Landsat, ESA’s recent launch of Sentinel 1-A, and so on, but what about the rest? In a recent blog, we used data from the Union of Concerned Scientists (UCS) and the United Nations Office for Outer Space Affairs (UNOOSA) to calculate there are currently 3,921 satellites orbiting the Earth; of which 1,167 are active. Today we’re focusing on the EO fleet, and for EO we’re going to count any satellite whose purpose is defined as EO, remote sensing, earth science or meteorology – it’s acknowledged that some satellites have more than one purpose.

According to the UCS database, at the end of January 2014, there were 192 EO satellites, the oldest of which is a Brazilian meteorology/EO satellite, SCD-1, launched in 1993. There are 45 nations/organisations with EO satellites in space and in terms of numerical supremacy, it’s a neck and neck race between China and the USA; China controls 25.5% of the fleet compared to USA’s 23.5% – although just over a third of the USA’ s fleet were jointly launched with other countries. After the front-runners, India has 7.29%, followed by Germany with 4.69% and Russia with 3.65%.

The picture of control becomes more interesting when you look at the four user groups for this EO fleet:

  • 56.77% are listed as used by Governments
  • 25.63% are listed as military satellites
  • 6.25% are commercial satellites
  • 4.17% are listed as being for civil uses; and
  • the remaining 7.18% are listed as being shared between two of the four user groups.

However, the space landscape is changing rapidly. Since the UCS database was updated there have been over 130 satellites launched; which have been dominated by Cubesats. The cheaper costs of Cubesats have removed a significant barrier to entry for new players to space; and we’ll see more commercial organisations becoming interested in space, like Google, and countries who traditionally haven’t had a presence in space getting a foothold. In addition, governments will be looking to launch satellites to build up their own space industry, something the UK has been focussing on for the last couple of years.

This changing environment will affect everyone working in the EO industry, particularly those in downstream activities, as there will be an increased number of datasets. Downstream companies will need to secure access to the new data to ensure they stay ahead of their competitors, and in a more commercial marketplace, this will almost certainly involve a cost. Strategic partnerships are going to become increasingly important in the EO world; and so don’t get left behind, start horizon scanning now and see where you need to position your company.

Remote Sensing Big Data: Possibilities and dangers

Remote sensing is an industry riding the crest of the big data wave. It offers great opportunities to those that can harness the power, but it’s also fraught with dangers. Big data is a blanket term used to describe datasets that are large and complex, due to the quantity of data, the speed at which new data becomes available or the variety of data. Remote sensing ticks all three of these boxes!

Sentinel-1 Netherlands

Sentinel-1 image of the coast of the Netherlands; courtesy of ESA

When I first started working with remote sensing, I approached the IT department to ask for 100 megabytes of disk space for my undergraduate project and was told nobody ever needs that much storage! Currently, the amount of Earth observation data available to the community is growing exponentially. To give you some examples, the recently launched Copernicus Sentinel 1-A satellite collects around 1.7 terabytes of data daily, the number of daily images collected by Landsat 8 has been increased by 18% this month and DigitalGlobe estimates it captures two petabytes of data each year. This quantity of data gives two key challenges; firstly, where to store it? Secondly, how do you know what data is valuable to enhance your decision-making?

It’s assumed the storage issue has been resolved by cloud computing, but there is a cost for getting the data to, and from, the cloud. An interesting recent study by the University of British Columbia discovered that over 80% of scientific data is lost within 20 years, mostly due to obsolete storage devices and email addresses. I have first-hand experiences of this. My PhD data was stored on hundreds of floppy disks and when I came to use them recently most didn’t work; fortunately I have a zip drive backup – although I still need to work out how to read Quattro Pro spreadsheets! I also have several Sun workstations with associated data on tapes which will only read from the machines they were written on; so how much of this data is accessible is debatable.

How often do you think about your old and archived data? Take a moment to consider how, and where, your critical data is stored. Is all of your data available and accessible? When was the last time the back-up procedures for your scientific or business data were tested? Does your IT department know which email addresses are critical for the receipt of satellite data?

The second challenge is knowing what data to use, particularly for people new to remote sensing. There is free data, paid for data, various satellites, various data types, various formats and the list can go on. The remote sensing community needs to help by providing more bridges between the data and the user community. The datasets available can offer huge benefits for business and science, but if people have to spend hours hunting round and trying to find the right image for them, they won’t stay users for long.

You can hire remote sensing companies, like us, who can offer impartial advice to help you select the right information. Pixalytics is striving to find more ways to make data more available, more accessible and more understandable. Remote sensing data belongs to everyone, and we need to support users to get it.

Is the Dead Sea in terminal decline?

The Dead Sea is located in the Jordan rift valley with a Jordanian border to the east and borders with Israel and Palestine to the west, and it has the lowest land elevation on Earth at over 400 metres below sea level.

Technically the Dead Sea isn’t a sea at all, it’s a hypersaline lake; the freshwater inflows from the Jordan River, and its associated tributaries, come into the land-locked Dead Sea where some of the water evaporates. This increases the waters salinity, it’s about nine and half times saltier than the ocean, and famously means people can happily float on it simply through natural buoyancy.

Despite having a surface area of almost four hundred square miles the Dead Sea is estimated to be shrinking at around one metre per year. Water levels have declined by approximately 30 metres since 1960 through to a combination increased usage and extraction upstream in the River Jordan, and a reduction in rainfall.

Dead Sea imagery from Landsat 5 in 1984 on the left, and Landsat 8 in 2014 on the right. Data courtesy of USGS.

Dead Sea imagery from Landsat 5 in 1984 on the left, and Landsat 8 in 2014 on the right. Data courtesy of USGS.

The changing shape of the Dead Sea can be seen in the Landsat image shown on the right which were both taken in the May/June period, but 30 years apart, the first in 1984 and the second in 2014. The shows a reduction in surface area alongside the development of evaporation ponds in the south that are maintained by pumping water from the northern basin – the Al-Lisān peninsula splits the sea into two unequal basins with northern basin being significantly larger and deeper. We also wondered if the recent 2014 image shows spontaneous crystallization in the surface waters, as described by Steinhorn in 1983. Could be worth further investigation?

A talk at the recent EARSeL conference also highlighted the problem of sink holes around the Dead Sea. Sink holes are being caused by the interaction of freshwater with subterranean salt layers; as the water level drops, salt is left behind in the soil and when freshwater washes through the soil the salts dissolve and cavities are created. Eventually, the subterranean structure loses integrity and sinkholes are formed. It’s estimates that there are around 3,000 sink holes in the Dead Sea region, but more worryingly a new sink hole opens up almost every single day!

The Dead Sea is one of the natural wonders of the world, and yet it’s slowing dying through shrinkage and sink holes. Remote sensing is a great monitoring tool for natural resources, but something needs to be done on ground if these images aren’t to become a modern day death mask.

34th EARSeL Symposium

Last week I attended the 34th Symposium of the European Association of Remote Sensing Laboratories, known as EARSeL, in Warsaw, Poland. Originally formed in 1977, EARSeL is a scientific network of academic and commercial remote sensing organisations. It aims include:

  • promoting education and training related to remote sensing and specifically Earth Observation (EO),
  • undertaking joint research projects on the use, and application, of remote sensing,
  • providing governmental, and non-governmental organisations, with a network of remote sensing experts.
EARSeL Bureau Handover Warsaw 2014

EARSeL Bureau Handover
Warsaw 2014

EARSeL is run by a Council of elected national representatives and an executive Bureau, elected by the Council. For the last year I have been proud to serve on the EARSeL executive Bureau as Treasurer for the organisation.  My term of office finished at the symposium, and I’d like to wish the new Bureau a successful year.

In addition I was also the co-chair and presenter for the Oceans & Coastal Zones session on the Monday afternoon and on the Wednesday I taught a session on ‘Introduction to optical data processing with BEAM’ as part of the joint EARSeL & ISPRS (International Society for Photogrammetry and Remote Sensing) Young Scientist Days which ran alongside the symposium.

For me the promotion of science generally, and specifically Earth Observation (EO), is an integral part of running Pixalytics. I want to support more people to understand and get involved; in particular, it’s vital that we educate and inspire the early career, and next generation, scientists.

It’s for these reasons that I enjoy working with, and being part of, organisations that are working to inform, educate and promote similar scientific aims. As well as EARSeL treasurer, I was also the Chair of the UK Remote Sensing and Photogrammetry Society (RSPSoc) for three years, and I’m currently vice-chairman of the British Association of Remote Sensing Companies (BARSC).

It can be challenging to balance the income earning side of Pixalytics with the volunteering side, but it’s worth it. There is a real case for businesses getting their employees to volunteer to support work outside of the company, whether it’s industry promotion, teaching or helping support social issues in the local community. Aside from the obvious support for the cause they are volunteering for, it can also help develop skills in time management, decision-making and leadership.

I’ve learnt a huge amount working with the different organisations, as well as developing skills I’ve met people outside my specialism and have strengthened by business network.  I have no intention of stopping volunteering, and I’ve always got one eye out for new opportunities. Volunteering can add value to your company, however large or small, and I’d recommend all organisations should consider the opportunities this could provide for them and their employees.

Pareto’s Principle and the Micro-Business

In last week’s blog we talked about the fact that running your own company gives you the freedom to explore your passion, with the flip side of the need to bring in money to pay your salary. Micro-business owners are responsible for everything, and so deciding how you balance your time between competing activities is a challenge.

Scientific research is at the heart of Pixalytics, but I also want to promote science. So for me I have to balance doing the work we have, bringing in new business, my scientific research, running the company and the volunteer roles I do to support the promotion of science; this week I’m in Warsaw attending the 34th EARSeL symposium.

I’m sure you’re all familiar with the Pareto Principle, originally set out by the Italian economist Alfredo Pareto in 1906 when he observed that 80% of the land was owned by 20% of the population. The 80/20 rule as it’s also known has been applied across business in a variety of ways. For example:

  • 80% of your sales come from 20% of your products,
  • 80% of software problems are caused by 20% of the bugs; and
  • 20% of your efforts should yield 80% of your results.

As you’ll have probably gathered from our blog I’m someone who likes to do lots of different things; so determining which 20% of my activities I need to focus on would be really useful. Over the last couple of months I’ve been reading ‘Essentialism: The Disciplined Pursuit of Less ‘ by Greg McKeown which is a variation on the 80/20 principles, but focuses on doing what you’re best at which is also probably what you enjoy most too!

The book’s message struck a chord. It made me realise I need to reduce the number of things I do, so I can focus and concentrate my effort on key tasks; essentially simplifying my life. These things are easy to say, but some of the small steps I’ve already taken are:

  • Unsubscribing from mailing lists I don’t read to reduce my in-box.
  • Immediately discounting meetings I don’t think will directly contribute to the business / my primary interests, even if my scientific half thinks they would be interesting!
  • Reducing the number of conferences and workshops I go to.
  • Reducing the number of presentations I give, so I’ll talk about something new rather than just updating the previous presentation with small increments.

These are first steps for me, but what about you? Have you given any thought to what is the most valuable 20% of your day, or perhaps more importantly what do you do with the other 80%. For example:

  • How much time do you spend being swamped with electronic data and information, rather than just accessing what you need?
  • Do you attend networking events because you feel you need to rather than want to or feel they’ll generate sales leads? (see our previous blog)
  • Do you spend time thinking about what you want to do, or do you go with the flow and not actually make conscious decisions?

For micro-business owners every task can seem critical, and it’s easy to carry on doing what we’ve always done – after all doing it has got us a business! However, this doesn’t mean everything you do is benefiting you or your business.

Take a few minutes to consider what you’ve done today. What has directly added value, and perhaps more importantly what hasn’t? Consider cutting down, or even cutting out, the activities not adding value. It should get you closer to identifying the mystical 20%.


Blog co-written with Bryony Hanlon, work placement student at Pixalytics.

Our Second Birthday!

At the end of last week LinkedIn reminded me that Pixalytics had now been in existence for two years. Where has the time gone? The first six months were spent transitioning out of my old company, setting up Pixalytics, having a holiday and getting our first contracts; although it didn’t happen as neatly as that list suggests!

Evolution of the Pixalytics logo over the last two years

Evolution of the Pixalytics logo over the last two years

The company’s first full year was 2013 and, like any new business, it was a combination of hard work, anxiety and enjoyment; at the end I was really pleased with what we’d achieved in the first year – particularly that I started receiving a salary! We’ve spent the first six months of 2014 developing a growth strategy for the company with advice from the Plymouth Science Park Mentoring Scheme to see how we can expand. We’ve got ideas, all we have to do is implement them now …I’m still surprised to be writing about my company. In the last 10 years I’ve gone from being a full-time academic, to 50/50 academic/commercial and then to full time commercial. My commercial journey began in 2007 with establishing a new company with some French colleagues, and then two years ago I left to set up Pixalytics.

I’ve been asked on numerous occasions whether setting up and running a company is stressful or frightening? Many people like the idea of running their own company, but are worried about taking the leap of faith it requires. When you’re running your company you have the freedom to explore what you’re passionate about, but you’re also responsible for bringing in the money to pay your salary. I love my work, seeing a problem where remote sensing can provide part, or all, of the solution; and thinking about how to turn the scientific research into a commercial opportunity. For me, this combination of pressure, independence and challenge is exciting.

So two years in, have we been successful? There are a lot of statistics that suggest around fifty to sixty percent of new business fail within the first two years, and given we’re still here that must be a positive. We’re seeing an increase in our profile, number of contacts and companies asking for our help, and we’re moving into developing new products and services. Of course I’d have liked to have grown faster, and there have been disappointments along the way, but overall we’re a growing, profitable company. It still feels that we’re only just starting and continuing to learn, if you want join our journey get in touch and we’ll see how we can help you.

Looking forward to the next two years, wherever they lead ….

The Science Behind Springwatch

Last Wednesday Pixalytics made it’s TV debut on the BBC2 Springwatch programme, where they showed a video we’d made on phytoplankton blooms.  The video was based on NASA MODIS-Aqua daily images. MODIS, or the Moderate-Resolution Imaging Spectroradiometer, is an optical sensor that’s used for mapping the both land and the oceans. It can be thought of as a digital camera that operates at a number of different wavelengths of light.

Spring 2014 phytoplankton image

Spring 2014 phytoplankton image, MODIS data from NASA with movie animation by Pixalytics Ltd.

As an ocean colour sensor it detects the change in colour of the ocean caused by what’s both dissolved and suspended in the water, e.g. the microscopic plants of the sea that are called phytoplankton. The chlorophyll pigments in plants (both on land and in the oceans) absorb light at blue and red wavelengths making waters high in phytoplankton appear green in colour. This colour change is picked up by chlorophyll algorithms (mathematical equations) and equated to changes in concentration that are displayed using a rainbow colour palette, which goes from purple to blue, green, yellow and red as the concentrations go from low to high values. Black on the imagery is where there’s no data, which for optical imagery is primarily due to cloud cover.

MODIS is on both the Aqua (travels south to north over the equator in the afternoon) and Terra (north to south across the equator in the morning) satellites, which orbit the Earth several times a day collecting strips of imagery 2330 km wide at a spatial resolution of around 1 km. The strips from a day are combined to create a daily composite image, and by looking at images over time we can see the changes in the phytoplankton concentrations as we as we move out of the winter through months into spring. The ‘spring bloom’ is an increase in phytoplankton concentrations as the days become lighter and the phytoplankton make use of the nutrients mixed into the surface waters over the winter.

Springwatch and GEO-Business Update!

Exciting News! Pixalytics made its television debut last night on BBC2’s Springwatch programme as part of a feature on plankton. We were asked to put together a video from satellite imagery showing the progress of a phytoplankton bloom around European waters for this spring, and it was shown alongside an interview with Dr Richard Kirby who we partner with on the Secchi Disk project. The video looked great on the programme and it was fantastic to see it, and for us to be name checked! Who knows where this television stardom might lead ….

The first day of Geo-Business 2014 was excellent! The Coastal and Hydrographic session at the conference had a great attendance, and Sam’s presentation on using Satellite Altimetry to determine water height

Geo-Business 2014 Conference!

Geo-Business 2014 Conference!

was really well received; a number of people are already wanting more information on the product, something we’ll be following up over the next few days.

The conference had a number of other interesting presentations, starting with keynote address by Neil Ackroyd from Ordnance Survey. His concepts of ‘data in itself isn’t enough’ and ‘look to simplify, rather than complicate, data’ really struck a chord with Sam, as this fits with the goals of our company in terms of making remote sensing data available to everyone without the need for specialist knowledge.

A later presentation from Carla Filitoco gave a positive snapshot of the current Earth Observation market. She highlighted the expected annual growth of 7% in downstream activities by 2015, which is great for those of us working in the sector – we’re hoping to beat that growth target ourselves!

In addition there were some interesting workshops, and it was the chance to catch up with old colleagues, and to meet new ones. Tomorrow we’ve got a number of meetings set up with fellow attendee’s, and are looking forward to developing some longer term relationships.

GEO-Business 2014 has been a well organised and popular conference, supported by a good variety of exhibitors. This looks like it’s going to become a regular event, and we’ll definitely be back! Anyone who is at the conference today and wants to catch up, get in touch by twitter or LinkedIn, we’d love to see you.