Why the Current Internet Satellite Space Race Matters?

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

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

The starting gun fired some time ago on the race to create a global satellite internet network. Last week OneWeb, backed by the Virgin Group and Qualcomm, stretched its legs with the announcement of a $500 million investment from companies including Airbus and Coke-Cola. The project intends to create a network of 648 microsatellites providing global high-speed internet and telephony services, to ensure everywhere on the planet has access. It’s planned these will be launched in batches, starting in 2017 with go live in 2019.

However, OneWeb isn’t the only runner in this race. Elon Musk’s Space X company, backed by Google, also has plans for a 4 000 strong internet satellite network; testing is due to begin in 2016 and current plans have it reaching full capacity around 2030.

These two developments could signal a change of pace in the satellite industry, as they will both be using mass produced satellites. Although neither project has realised the specifications for their microsatellites, some details are available. Both networks will be in Low Earth Orbits of around 1100 to 1200 km, weights will also be similar with OneWeb’s at 150 kg and Space X’s slightly more at around 200 kg. The microsatellite size is expected to be around half a square metre – although little has been announced about this to date; Airbus was recently awarded the build contract for OneWeb. Both constellations plan to use the microwave frequency Ku band, although Space X has also indicated interest in the Ka band.

Apart from mass production, the other element of these networks worth thinking about is the sheer quantity of satellites involved. The United Nations Office of Outer Space Affairs recorded 239 satellites launched last year, and this was the greatest number ever launched in a single year. According to the Union of Concerned Scientists last satellite database, from 31 January 2015, there are current 1 265 satellites in orbit around the Earth. Therefore, if both of these projects cross the finish line, they will more than quadruple the current number of satellites.

More objects in space increases the likelihood of potential collisions and impacts, and increases the potential space junk and debris in the atmosphere – although, OneWeb has already announced plans for deorbiting its satellites at end of life. This increase of objects in LEO does bring to mind the Kessler Syndrome hypothesized by Donald Kessler in 1978. He proposed a scenario where the density of objects in LEO is so great that the debris from a single collision between two objects would set off a cascade of subsequent collisions so great, that it would prevent any further spacecraft from passing through the LEO area; as explored in the 2013 film Gravity. This level of satellite concentration will need careful managing and monitoring.

In terms of Earth observation, the satellites will probably cause minimal impact. Due to their size, they will show up as rogue pixels on very high-resolution images, but wouldn’t register on the coarser resolution of systems such as Landsat. In terms of frequency bands, the Ku band isn’t generally used for Earth observation; although the altimeter, ALTIKA, onboard the joint French and Indian SARAL mission does operate at the Ka band and any use of that band by the Space X project will be worth watching. This isn’t the first time Earth observation has had to fight its corner for bandwidth, there is an ongoing battle with mobile data companies for use of these microwave frequencies that could also be used for wireless data transmission.

The internet satellite space race is an event that must be watched, it will change the satellite and telecommunication industries; and has the potential to change fundamentally what orbits the Earth.

Month on the World’s Oceans

San Francisco USA, Pseudo-true colour image. Landsat 8 data courtesy USGS/NASA/ESA

San Francisco USA, Pseudo-true colour image. Landsat 8 data courtesy USGS/NASA/ESA

June’s been a really busy month for me on the world’s oceans. I’ve not actually been out on the water, but flying over it having attended both the World Ocean Summit and the International Ocean Colour Science (IOCS) meeting. Both of these events focussed on the oceans, although they had very different participants and perspectives. In addition, the 8th June was also World Oceans Day and had the theme ‘Healthy Oceans, Healthy Planet’.

The World Ocean Summit, organised by The Economist, took place at the start of June in Cascais, Portugal. It focused on the development of the blue economy, with most of the participants from governments or non-profit non-governmental organizations. There were a number of talks highlighting the potential innovation opportunities the world’s ocean might offer, and the policy and worldwide governance framework needed. Throughout the summit, there was a repeatedly voiced concern over the state of the world’s oceans, and the serious peril and decline it’s in. Whilst many large organisations are now looking to exploit the oceans, many local communities have been doing this for years and they are seeing changes and challenges. The oceans are an integral part of Earth’s ecosystem, and without them we could not survive on this planet. The resources are potentially huge, but tapping into these requires a co-ordinated bottom up approach. Otherwise we risk damaging the ocean and our own existence.

My second major event was IOCS last week in San Francisco, and as the name suggests the meeting focused on mapping and understanding the ocean through the use of ocean colour remote sensing i.e., detecting and quantifying what causes changes in the colour. The participants were mostly scientists, students and space agencies, who were discussing current work and future plans. There was obvious excitement over the launch of Sentinel-2 (which incidentally occurred successfully very early yesterday morning) and Sentinel-3, which will carry the OLCI ocean colour sensor, due to be launched towards the end of this year. Cloud cover remains a limiting factor in many locations, as clouds get in the way when optically sensing of the ocean and so the more data collected the better insight we’ll gain into the complexities of the biological processes.

There were lots of new areas of focus discussed at the meeting. I was particularly interested in exporting of carbon to the deep ocean and the calculation of uncertainties i.e., how well have we estimated the values that have been derived.

I was also fascinated by the development in our understanding of rapidly changing ecosystems, such as the Arabian Sea and high latitude polar oceans, which are strongly affected by the effects of climate changing; for example, the reduction of the snow cover over the Himalayan-Tibetan Plateau region changes the strength of the Asian monsoon season, which in turn impacts the phytoplankton that bloom in the Arabian Sea. This has caused a particular species of plankton to bloom (Noctiluca, also known as sea sparkle because it can glow when disturbed at night), which are eaten by jellyfish but can negatively affect fisheries as they’re too big for zooplankton to eat.

I’d love to say after a busy month it’s good be home, but I’ve not quite got there yet! I went straight from San Francisco to Switzerland, where this week I’m attending the 2015 Dragon Symposium that’s focused on an Earth observation scientific exchange programme between the European Space Agency and China.

Sentinel-2A Ready To Start Its Watch

Integration of the Vega VV05, carrying Sentinel-2A, in the launcher assembly area at Europe's Spaceport in Kourou, French Guiana, on 11 June 2015. Image courtesy of ESA–M. Pedoussaut, 2015

Integration of the Vega VV05, carrying Sentinel-2A, in the launcher assembly area at Europe’s Spaceport in Kourou, French Guiana, on 11 June 2015.
Image courtesy of ESA–M. Pedoussaut, 2015

Sentinel-2A is due to be launched next Tuesday, 23rd June, from French Guiana. It’s the second satellite in the joint European Union and European Space Agency Copernicus programme, following Sentinel-1A’s launch in April 2014. Sentinel-2A carries a Multispectral Imager (MSI) that has 13 spectral bands:

  • 4 visible and near infra red 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

It’s advantages over the US Geological Survey Landsat-8 mission includes the higher spatial resolution, and that Sentinel-2A is the first in a pair of satellites that will operate in tandem; Sentinel-2B is due to be launched next year. The key advantage of having an identical paired satellite constellation is that they can map the Earth much faster. On its own Sentinel-2A will return to the same point above the Earth, referred to as the revisit time, every 10 days; whereas it’s currently 16 days for Landsat-8. However, when Sentinel-2B is added the revisit time will halve to only 5 days at the equator. This improvement is hugely significant for the development of time critical applications. Also, there are plans to work Landsat-8 and Sentinel-2 together to provide an even higher repeat coverage of around twice a week

When both Sentinel-2 satellites are operational, they will acquire over 1 Tb of data every single day, and currently this data has ESA Sentinel-2:

  • Land Use & Land Cover (LULC) Monitoring – Providing data on how land on the planet is used, and helping to monitor how this changes over time. For example, monitoring deforestation, desertification, reforestation, drying up of wetlands, urban creep and flood mapping amongst others. The European Commission leads the way in this type of monitoring with the CORINE Land Cover Project, which has produced European wide maps for 1990, 2000, 2006 and 2012 that classify 44 different types of land; available through the Copernicus Land Service.
  • Plant Health – Providing information on vegetation and growth such as leaf water content, which will be particularly helpful for farmers in determining when, and how much, to water crops to improve yields. Also wider uses such as the leaf area index (LAI), which is one of the Essential Climate Variables used by the United Nations to monitor climate change.
  • Inland and Coastal Water Management – Providing higher resolution ocean colour data than available from ocean colour missions, such as MODIS and VIIRS, that supports the monitoring of water quality. Using products such as Chlorophyll-a to help the identification, and mapping, of harmful phytoplankton algal blooms, and turbidity to measure water clarity.
  • Disaster Mapping – Supporting a variety of disaster situations through the Copernicus Emergency Management Service.

The Copernicus satellite programme offers an exciting new data source and is made available free of charge to users, making this a critical resource for everyone working in the Earth observation industry. Every company needs to look at what new products and services they could develop from Copernicus data, or how they can make existing processes more efficiently and effectively. If you don’t, you can guarantee someone else will. How are you going to the use Sentinel-2A data?

Three years and beyond …

3rd BirthdayThe start of June marked the three-year anniversary of Pixalytics! Given that statistics indicate almost half of all start up businesses fail with the first three years, the fact that we are still here is a major success!

Not only that, but in the last twelve months we grew turnover a little, paid salaries for the whole year, didn’t take on any more debt and had our first employee – albeit a fixed term and part-time employee, but an employee nonetheless! All of which we considered to be achievements; however we want more.

As any small business owner knows, it’s very easy to get sucked into the treadmill of finding work, completing the work, getting paid and then going straight back to finding more work. You spend so much time working in the company, there isn’t any time to work on the company which is critical for growth and development. During the second half of 2014, we spent time working on Pixalytics.

We’re in a mentoring scheme where we are based and we’ve worked with our mentor, Phil Johnston, to better understand our business. Having the external critical friend asking the awkward questions isn’t easy, sometimes we couldn’t answer Phil, sometimes we didn’t want to answer Phil and sometimes we completely disagreed with Phil. However, all of his questions made us think harder about what Pixalytics was and how we wanted to develop it. By the end of 2014 we’d updated our company brand, marketing materials, website and our strategic thinking.

We’re a science company, and we like to experiment and see what happens. At the start of 2015 we were ready to start our growth strategy. So far this year, we’ve:

  • We’ve written a book! The Practical Handbook of Remote Sensing is due to be published in October/November 2015.
  • Exhibited for the first time at GEO Business 2015, and we’ll also be exhibiting at the 2015 UK Space Conference.
  • Expanded both our customer base and the services we offer.
  • Started developing new ways of interacting with our clients.
  • Forecasting growth this year in excess of 35%.

We still have a long way to go, to get to where we want to be; we need to continue to develop the customer base and the products we offer. Andy is spending more and more time within the business and this will continue to grow, but we’d like to get to the point of being able to employee someone else full time.

The first three years have been a huge learning curve, we’ve made some mistakes and there are certain things we’d do differently. We experiment and if things don’t work out; we remember the words of Samuel Beckett:

Ever tried. Ever failed. No matter. Try Again. Fail again. Fail better.

We’re a growing small company, and we want to do all we can to make sure it stays that way for the next three years and beyond.

Ten Top Tips for First Time Exhibitors

Pixalytics promotional postcards

Pixalytics promotional postcards

This is the last blog in our quartet covering our first experience of exhibiting; and today we’re going cover the top tips we wish we’d known before arriving at the exhibition.

  1. Know your sizes: We had a 2m by 2m exhibition stand and in addition, we’d bought a furniture package and hired a TV. When we arrived on build day, the furniture and TV stand took up so much space we wondered if we’d get in the stand let alone any potential customers! It looked like we had bought far too much equipment for your stand.
  2. Don’t start stand building too early: We knew our stand would not take hours to build, but wanted to give ourselves plenty of time. Stand building began at 8.00am, and when we arrived at 10.00am the venue was full of construction workers, power tools galore and metal bars that looked like they should be on a bridge somewhere! Just getting to our stand was an obstacle course, so we had a look around Islington in the morning and came back to a quieter exhibition venue in the afternoon.
  3. Have back up plans – We had a stand design in our heads, but it started to unravel immediately. The furniture was bigger than anticipated – see tip one! The stand walls weren’t fixed, they flexed; this meant we could not get enough pressure on the solid canvases to lock the Velcro strips, which were the recommended attachment method. Hence, our canvases would not stay up. (During the exhibition, we saw other exhibitors had attached things by using hooks over the stand walls, giving us a future construction method).After a bit of brainstorming, we used our furniture as display stands instead! It was not our original plan, but worked.
  4. Take a bag of useful items – Having items such as scissors, tape, stapler, bulldog clips, etc, made brainstorming and changing our plans (see tip 3) easier as we had options. For example, we used bulldog clips to hold up our flag bunting.
  5. Movie, not PowerPoint – The hired TV took a memory stick, but only displayed pictures or movies, and not the PowerPoint presentation we’d prepared. We converted the presentation overnight, but needed a little bit of help from the onsite TV people to put it on continuous loop.
  6. Don’t beat yourself up – From previous blogs, you’ll know we’re a small company doing an economical stand, and we were concerned how it would compare with the big companies. Our stand was different, and it looked like no other at the exhibition. It did generate a lot of talk. Our flag bunting split the crowd; some had bunting envy, others didn’t like it. However, it provided a great talking point for visitors – see tip 9.
  7. If you’re stuck, ask for help – All the exhibition organisers, equipment suppliers and venue staff were really helpful, and we got great assistance on everything we asked about including missing table foot, help on setting up the TV (see tip 4) and we’d like to extend a special thank you to Sophie who drew the winner of our prize draw.
  8. Buy less promotional items – On a previous blog we mentioned our decisions on which promotional items to take. The postcards were very successful, the leaflets were useful and the pens were fine (although, almost every stand offered free pens). What we didn’t get right were the quantities, we had bought far too many! Small businesses are resourceful, so the postcards will become our compliment slips and we’ll use the pens in the office … for most of the next decade!
  9. Talk to the visitors – I know it’s an obvious thing to say, but you have talk to people. It’s easy to stand and smile at people as they walk past, but it’s when you start talking to them that things happen. We were able to attract people onto the stand with our postcards and prize draw, and then we could start talking to them, which led to a number of unexpected and interesting conversations and possible leads.
  10. It is tiring!!! – It is exhausting standing around and talking to people all day, particularly when you are more used to being sat in an office. At the end of each day we were delighted to take our shoes off!

So was it worth it? Regularly blog readers will know this has been something we’ve been wondering for our first exhibition.

On the business side we spoke to many people, some we already knew and some we did not; both groups generated conversations and potential leads. The question is whether any of these leads will turn into actual turnover over the coming months.

On the exhibition side, we learnt a lot! We’ve got a small business stand at the 2015 UK Space Conference in Liverpool in July, which is a slightly different approach as we only have a space with a table and chairs, so it will provide an interesting comparison. We look forward to meeting any fellow GEO Business exhibitors also going to Liverpool.

We‘re on Stand K31 at Geo Business 2015!

We’ve made it! We’re officially first time exhibitors! After months of discussions, decisions and preparations, at this precise moment you’ll find us on stand K31 at the Geo Business Show 2015 in the Business Design Centre in London.

In a previous week, we discussed our approach to the exhibition and wanting to have something different that stands out without breaking the bank. The blog picture reveals our stand design; we’ve large scale canvas prints of a variety of satellite images coupled with retro items such as a globe and map bunting. We were a little worried about our stand construction, but it all seemed to go went well. Let us know what you think?

South West UK, Pseudo-true colour image. Landsat 8 data courtesy USGS/NASA

South West UK, Pseudo-true colour image. Landsat 8 data courtesy USGS/NASA

In terms of promotional items, we have our brochures, postcards of all the canvas prints, a number of A5 sheets on our key products/services and our pens. In addition, we’re giving away a small canvas Landsat image of South Devon, as shown on the right. Come on drop your business card or complete an entry form off at our stand, and we’ll select the winner tomorrow before the exhibition closes.

Geo Business 2015 runs both today and tomorrow, and so do come along and have a look at our stand. Give us some feedback on our design, enter the competition or just pick up a few postcards or a pen! If you feel like it, talk to us! We’d be glad to discuss remote sensing, Earth observation and all things Pixalytics with you; maybe find out if there is anything we might be able to help you, or your organisation, with. Who knows what ideas, products or solutions our discussions might come up with?

Don’t forget, tomorrow at 12.30pm in Room F, we’re running a free workshop called ‘How to add value to remote sensing by applying cutting edge scientific research to create richer imagery and data’. It would be great to see people there.

Finally, we’ve also previously talked about how we’d determine whether all of this effort is worthwhile. We’ve come up with these three metrics to measure our toe dipping into the exhibition world:

  • New contacts for customers or research partners.
  • In the next four months, gain sufficient new client business from the exhibition to cover our costs – after all this is why we are all exhibiting!
  • Develop a long-term business relationship over the course of the next year.

We’ll let you know how we got on next week. However, if you’re at Geo Business today or tomorrow why not come up and have look, talk to us and take away a few freebies. We’d love to see you.

GEO Business 2015: Adding Value to Remote Sensing

Pixalytics-show preview imageTechnological developments have made it easier, faster and cheaper to launch a satellite, and have enhanced the capabilities of the sensors onboard. This has led to an ever-increasing quantity of available data. Also, there is recognition within the space industry that it’s no longer enough to launch something into orbit, the satellite customers need to also see how they’ll get value from the data it collects.

Our workshop session at GEO Business 2015 will focus on this issue. We’ll be describing the approach we take in ‘How to add value to remote sensing by applying cutting edge scientific research to create richer imagery and data’. Anyone who knows us, or who are regular blog readers, will know that science is firmly at the heart of Pixalytics. We believe Earth observation needs to go beyond the simple provision of remote sensing data or imagery, it should produce new, innovative and unique ways of utilising the terabytes of available data. Our approach includes:

  • Research & Development – Developing innovative techniques by applying new research methodologies, such as our product that measures water heights from space using altimetry data.
  • Repurposing – Using data for more purposes than originally intended, as is happening in the US where they are using ocean colour techniques for inland waters.
  • Merging Data Sets – Using remote sensing data combined with scientific, government or other open source data to produce more than is possible with just one data type.
  • Expanding Markets – Getting people who don’t use remote sensing to think about how they could use it within their businesses and organisations.
  • Blended Solutions – Developing automated processing for data extraction and downloading, which provides visualisation solutions whenever and wherever data is needed.

If you are at GEO Business on Thursday 28th May, our workshop will be taking place just before lunch at 12.30pm in Room F and it would be great to see you there.

Talking of GEO Business, we had a great response to last week’s blog on the things we’d learnt so far preparing for our first exhibition. We had a number of suggestions on how to measure success, which was the one thing we said we didn’t know last week! Interestingly, Elaine Ball Technical Marketing are running a Twitter chat on Thursday at 4pm relating to GEO Business, and one of their questions is looking at this issue of success. It will be good to see more thoughts on the topic.

We also got a lot of advice about exhibiting. The idea of taking a duster along was something we’ve have never thought of, but it seems so obvious when you think about it. The ‘rules’ of running a stand that people sent in made great reading; ensuring we don’t start working on the laptop and phones will be something we’ll have to be vigilant of!

Our stand kit is coming together, although we’re still holding our breath over a couple of promised deliveries. How the construction of the stand will come together is shrouded in a little mystery for us, but it will certainly make next Tuesday entertaining.

If any blog readers are around the Business Design Centre next Wednesday and Thursday, please come up and say hello, we’d love to meet you; and you will have the chance to win the free prize raffle we’ll be running on the stand. Hope to see you next week!

5 Things We’ve Learnt Preparing For Our First Exhibition & the 1 Thing We Haven’t!

GlobePixalytics is becoming a conference exhibitor! After years of attending conferences, we decided, for the first time, to become an exhibitor. We are undertaking two exhibitions this year, and our first is GEO Business 2015 taking place later this month on the 27th and 28th at the Business Design Centre, in London. As complete novices in the exhibition world, we’ve had an interesting learning curve. Here are five lessons we’ve learnt during our preparation, and the one thing we still don’t know.

  1. Everything Costs! We bought an exhibition space, which has three walls and our name above it. We knew we’d have fill the shell to create the stand, but hadn’t realised exactly what this meant. It’s obvious now, but we hadn’t thought about the need to have electricity connected on the stand, various options for furniture, hiring equipment, getting things to our stand and how you actually attach items to the stand. We discovered that there is a solution to these, and numerous other things, but they all have a cost. Buying the stand space is only the start, and this has made us rethink everything from stand design to our travel arrangements.
  2. Stand Design. We knew we couldn’t compete with the big firms with their cappuccino machines, freshly baked cakes and leather chairs. We had to go for something different, and so we’ve attempted to create interesting, intriguing, slightly vintage and cost effective stand (see lesson 1!). If you are at GEO Business come along and tell us what you think. As a sneak preview, the blog picture is part of our stand.
  3. Promotional Items. You need to have promotional items, freebies and things to hand out; but the question is what? We wanted items that were interesting, promoted us and ideally would make it back to the desks of potential customers. We discounted novelty items, expensive items (see lesson 1!) and unwrapped sweets (you never known where people’s hands have been!). We’ve settled for pens (useful, and might make it back to desks) and postcards (interesting and promoting us); wrapped sweets are still being debated, you’ll have to come onto the stand to find out the decision.
  4. Talk To People, Not The Internet. A lot of the exhibition preparation can be done on the internet and by email, but we had lots of questions. We found it was far easy to talk to people, rather than simply fill out forms. We gained a lot of information by talking to the conference organising team (thank you Danielle) the company hiring the audio-visual equipment were helpful and our promotional material suppliers (Adam from Redrok was great!).
  5. Expect Phone Calls. We got a lot of phone calls once our participation was on the exhibition website, all of which were trying to sell us something! The most surprising were the numerous, and we do mean numerous, calls we’ve had offering us discounted hotel rooms.

So these are the five things we’ve learnt in our preparation, and I’m sure there will be more to learn during the stand construction and the exhibition itself. So what about the one thing we haven’t learnt? The thing we have no idea about is whether all of this effort will be worth it.

So a question for all experienced exhibitioners, how do you decide if an exhibition stand has been worthwhile? Is it the number of business cards collected, number of people spoken to, amount of publicity generated or is it about the amount of new work generated? Drop us a comment, or a tweet to @pixalytics, telling us how you measure exhibition success.

If you are coming to GEO Business 2015, please drop by the stand and say hello.

How to Measure Heights From Space?

Combining two Sentinel-1A radar scans from 17 and 29 April 2015, this interferogram shows changes on the ground that occurred during the 25 April earthquake that struck Nepal. Contains Copernicus data (2015)/ESA/Norut/PPO.labs/COMET–ESA SEOM INSARAP study

Combining two Sentinel-1A radar scans from 17 and 29 April 2015, this interferogram shows changes on the ground that occurred during the 25 April earthquake that struck Nepal. Contains Copernicus data (2015)/ESA/Norut/PPO.labs/COMET–ESA SEOM INSARAP study

Accurately measuring the height of buildings, mountains or water bodies is possible from space. Active satellite sensors send out pulses of energy towards the Earth, and measure the strength and origin of the energy received back enabling them to determine of the heights of objects struck by the pulse energy on Earth.

This measurement of the time it takes an energy pulse to return to the sensor, can be used for both optical and microwave data. Optical techniques such as Lidar send out a laser pulse; however within this blog we’re going to focus on techniques using microwave energy, which operate within the Ku, C, S and Ka frequency bands.

Altimetry is a traditional technique for measuring heights. This type of technique is termed Low Resolution Mode, as it sends out a pulse of energy that return as a wide footprint on the Earth’s surface. Therefore, care needs to be taken with variable surfaces as the energy reflected back to the sensor gives measurements from different surfaces. The signal also needs to be corrected for speed of travel through the atmosphere and small changes in the orbit of the satellite, before it can be used to calculate a height to centimetre accuracy. Satellites that use this type of methodology include Jason-2, which operates at the Ku frequency, and Saral/AltiKa operating in the Ka band. Pixalytics has been working on a technique to measure river and flood water heights using this type of satellite data. This would have a wide range of applications in both remote area monitoring, early warning systems, disaster relief, and as shown in the paper ‘Challenges for GIS remain around the uncertainty and availability of data’ by Tina Thomson, offers potential for the insurance and risk industries.

A second methodology for measuring heights using microwave data is Interferometric Synthetic Aperture Radar (InSAR), which uses phase measurements from two or more successive satellite SAR images to determine the Earth’s shape and topography. It can calculate millimetre scale changes in heights and can be used to monitor natural hazards and subsidence. InSAR is useful with relatively static surfaces, such as buildings, as the successive satellite images can be accurately compared. However, where you have dynamic surfaces, such as water, the technique is much more difficult to use as the surface will have naturally changed between images. Both ESA’s Sentinel-1 and the CryoSat-2 carry instruments where this technique can be applied.

The image at the top of the blog is an interferogram using data collected by Sentinel-1 in the aftermath of the recent earthquake in Nepal. The colours on the image reflect the movement of ground between the before, and after, image; and initial investigations from scientists indicates that Mount Everest has shrunk by 2.8 cm (1 inch) following the quake; although this needs further research to confirm the height change.

From the largest mountain to the smallest changes, satellite data can help measure heights across the world.

Ocean Colour Cubes

August 2009 Monthly Chlorophyll-a Composite; data courtesy of the ESA Ocean Colour Climate Change Initiative project

August 2009 Monthly Chlorophyll-a Composite; data courtesy of the ESA Ocean Colour Climate Change Initiative project

It’s an exciting time to be in ocean colour! A couple of weeks ago we highlighted the new US partnership using ocean colour as an early warning system for harmful freshwater algae blooms, and last week a new ocean colour CubeSat development was announced.

Ocean colour is something very close to our heart; it was the basis of Sam’s PhD and a field of research she is highly active in today. When Sam began studying her PhD, Coastal Zone Color Scanner (CZCS) was the main source of satellite ocean colour data, until it was superseded by the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) that became the focus of her role at Plymouth Marine Laboratory.

Currently, there are a number ocean colour instruments in orbit:

  • NASA’s twin MODIS instruments on the Terra and Aqua satellites
  • NOAA’s Visible Infrared Imager Radiometer Suite (VIIRS)
  • China’s Medium Resolution Spectral Imager (MERSI), Chinese Ocean Colour and Temperature Scanner (COCTS) and Coastal Zone Imager (CZI) onboard several satellites
  • South Korea’s Geostationary Ocean Color Imager (GOCI)
  • India’s Ocean Colour Monitor on-board Oceansat-2

Despite having these instruments in orbit, there is very limited global ocean colour data available for research applications. This is because the Chinese data is not easily accessible outside China, Oceansat-2 data isn’t of sufficient quality for climate research and GOCI is a geostationary satellite so the data is only for a limited geographical area focussed on South Korea. With MODIS, the Terra satellite has limited ocean colour applications due to issues with its mirror and hence calibration; and recently the calibration on Aqua has also become unstable due to its age. Therefore, the ocean colour community is just left with VIIRS; and the data from this instrument has only been recently proved.

With limited good quality ocean colour data, there is significant concern over the potential loss of continuity in this valuable dataset. The next planned instrument to provide a global dataset will be OLCI onboard ESA’s Sentinel 3A, due to be launched in November 2015; with everyone having their fingers crossed that MODIS will hang on until then.

Launching a satellite takes time and money, and satellites carrying ocean colour sensors have generally been big, for example, Sentinel 3A weighs 1250 kg and MODIS 228.7 kg. This is why the project was announced last week to build two Ocean Colour CubeSats is so exciting; they are planned to weigh only 4 kg which reduces both the expense and the launch lead time.

The project, called SOCON (Sustained Ocean Observation from Nanosatellites), will see Clyde Space, from Glasgow in the UK, will build an initial two prototype SeaHawk CubeSats with HawkEye Ocean Colour Sensors, with a ground resolution of between 75 m and 150 m per pixel to be launched in early 2017. The project consortium includes the University of North Carolina, NASA’s Goddard Space Flight Centre, Hawk Institute for Space Sciences and Cloudland Instruments. The eventual aim is to have constellations of CubeSats providing a global view of both ocean and inland waters.

There are a number of other planned ocean colour satellite launches in the next ten years including following on missions such as Oceansat-3, two missions from China, GOCI 2, and a second VIIRS mission.

With new missions, new data applications and miniaturised technology, we could be entering a purple patch for ocean colour data – although purple in ocean colour usually represents a Chlorophyll-a concentration of around 0.01 mg/m3 on the standard SeaWiFS colour palette as shown on the image at the top of the page.

We’re truly excited and looking forward to research, products and services this golden age may offer.