Chinese Satellites Going Up, Chinese Satellite Coming Down

Satellites orbiting the Earth

Artist’s rendition of satellites orbiting the Earth – rottenman/123RF Stock Photo

It’s been a busy weekend for the Chinese space industry! On Saturday the China National Space Administration (CNSA) launched three new high resolution Gaofen-1 optical Earth Observation satellites from the Taiyuan Satellite Launch Centre in the north western Shanxi Province of China.

The three new satellites, called Gaofen-1: 02, 03 and 04 respectively, were launched into  sun-synchronous 645 km orbits at 03:22 GMT on the 31st March. They all carry two high resolution cameras, which are capable of acquiring multispectral data at eight metre spatial resolution, and this improves to around two metre resolution for the panchromatic band.

They are believed to be the next generation of the Gaofen-1 satellite which was originally launched on the 26th April 2013. It also carried the two high resolution cameras, but alongside had a wide field imager which is not included on the latest launches.

Saturday’s satellites will operate as a constellation offering a revisit time of two days, with the orbit repeating itself every fifteen days. However, for the foreseeable future, the constellation will also include the original Gaofen-1 satellite and will provide an impressive one-day revisit time and eleven day global coverage. The data from these satellites will be used for applications such as disaster warning, environmental monitoring, construction, transportation and emergency response.

The contrast to these launches was the re-entry of the Tiangong-1 space lab into Earth’s atmosphere on Monday 2 April at 00:15 GMT. Tiangong-1, which translates as Heavenly Palace 1, was originally launched on 29 September 2011. It had a two year operational lifecycle and has orbited the Earth unmanned for almost five years. During 2017, it was announced that the CNSA no longer had any control over Tiangong-1 and that it would gradually fall back to Earth over the coming eighteen months.

This satellite’s demise has caused a lot of public interest. Due in part to greater interest in space debris, but also due to the size and difficulty of determining exactly where it might fall to Earth!

End of life satellites falling back to Earth isn’t a rare occurrence, on average around one satellite each week enters our atmosphere and over a year this equates to around 100 tonnes of metal. The vast majority of this burns up in the atmosphere and apart from offering an interesting occasional fireball backdrop to the sky, it has no impact. Occasionally some of the debris does fall to Earth although most of this tends to be over water.

The difference here is size and mass. Tiangong-1 was 12 m long with a diameter of 3.3 m and had a launch mass of 8,506 kg – although obviously this will be less now.

Tracking space debris is becoming more and more important, and there were 14 space agencies/organisations, collectively known as the Inter Agency Space Debris Co-ordination Committee, tracking Tiangong-1 including NASA, ESA, European national space agencies, JAXA, ISRO, KARI, Roscosmos and the Chinese CNSA themselves.

Despite all of this effort focussed on Tiangong-1, it was very difficult for this group to forecast what debris might fall to Earth and where it might hit. Even when they confirmed entry, it was suggested that debris could hit somewhere in the South Pacific which is a very vague, and large, area.

Generally, it is being reported that most of the space lab burnt up in the atmosphere. However, despite all the effort placed tracking the object in space, there is no similar arrangement to track any debris that might reach the Earth’s surface and so no-one is sure how much, if anything, actually made it back. It may be the coming days, weeks or even months before we find anything that hit land and we may never know if it did hit the ocean.

This weekend just goes to show that the space industry is constantly changing.

Blue Phase at Wavelength 2018

Blue John Cavern

Last week I attended the 2018 Wavelength Conference in Sheffield. This is an annual gathering for the Remote Sensing and Photogrammetry Society (RSPSoc) and is geared towards PhD students and early career scientists. The conference aim is to provide a welcoming and constructive atmosphere to present research and progress towards PhD’s, coupled with a vibrant social programme.

This was my first experience of a remote sensing conference and the cosy nature of the common room where it was held alongside the lack of pressure of a larger event lent itself well to its ambition.

The topics covered by the research varied greatly, each with a focus on how to apply remote sensing and photogrammetry techniques in novel ways to better understand the world around us. These ranged from tracking whales to monitoring rice fields and developing systems to track small scale landslides.

One key technology which was popular among the presentations was the application of machine learning, the training of an artificial intelligence (AI) to classify images for a variety of purposes. Given it is something I’m becoming involved in at Pixalytics, every mention of AI attracted my attention. One presentation which stuck out for me was its application to track the effects of crude oil pollution in the Niger delta region. Harnessing remote sensing data and utilising the power of machine learning to sift through hundreds or even thousands of images, classify details and pick out objects of interest to monitor environmental damage is a novel approach. It provides a direct link from the science to a serious real-world issue. Whilst a localised case, the techniques demonstrated have the potential to better inform our responses to these issues which in turn will help people being affected by these disasters.

This application of science combined with the potential to one day help people resonated with me greatly. It reminded me of the work I am currently doing on the Drought and Flood Mitigation Service project which will aid the lives of Ugandan farmers.

Two keynotes were delivered during the conference, one by Dr. Alistair Graham, from Geoger Ltd, and one from the Chairman of RSPSoc Dr. Richard Armitage. Dr. Graham’s keynote was fascinating as he delivered his experiences working in a multitude of different environments from corporate to SME’s in industry to post doc positions in academia. He explained the nuances of working in each area and the possible paths for career progression open to PhD students and other early career scientists. I fall into the latter category, but the perspective he provided convinced me to keep my options open for the future. At a time when industry and academia is changing rapidly anything could happen.

Dr. Armitage’s keynote was on responsive remote sensing and his talk focused on how to use the right remote sensing data at the right time and for the right area. For the problems we come across, identifying the correct approach to take with remote sensing data is crucial.

For example, two important factors to consider for any problem are spatial resolution and data type. Some features require 5m to be visible, whereas for others the 30m resolution can show what is required. Further to consider is what type of data is best suited for the problem, optical data has its advantages but infra-red can reveal insights that optical data cannot. Having come across these points before the keynote, it served as a good reinforcement on the topic.

Blue John in the rock.

The highlight of the conference for me was the tour around Blue John cavern. Tucked away in the Peak District, surrounded by stunning views of the hills, the cavern is home to the famous Blue John stone. The tour guide was a miner who had worked in the cavern for 15 years and his knowledge on the tour was remarkable, making every stop ever more interesting.

Whilst a lot of walking and climbing was done, the colourful Blue John that spotted the walls of the cavern, together with the extremely high ceilings carved out by long gone rivers made for amazing views. If you don’t mind cramped spaces and traversing up and down a large mine, then Blue John cavern is a fantastic place to go!

For my first conference experience Wavelength 2018 was a fantastic introduction. The welcoming atmosphere, getting to see the diverse nature of remote sensing and photogrammetry research going on right now and the insightful keynotes will stick with me for a long time. I highly recommend any early career scientist or PhD student to attend the next incarnation of this conference.

Chris Doyle
Junior Software Developer
Pixalytics Ltd

Picking Up Penguins From Space

Danger Islands, off Antarctica. Landsat-8 image acquired on 7th December 2017. Image courtesy of NASA/USGS.

World Wildlife Day is the 3rd March, and so fittingly this blog is looking at how satellite imagery and remote sensing techniques were used to recently discover an unknown colony of 1.5 million Adélie penguins on the Danger Islands off the Antarctica Peninsula in the north-western Weddell Sea. Adélie penguins only live along the Antarctic coast, and they grow to a height of around 70cm and weigh between three and six kilograms.

The paper by ‘Multi-modal survey of Adélie penguin mega-colonies reveals the Danger Islands as a seabird hotspot by Borowicz et al was published in Scientific Reports on the 2nd March 2018. It is interestingly not only because of the discovery of unknown penguins but also because the research combines historic aerial imagery, satellite imagery, drone footage and remote sensing techniques.

The research has its roots in an earlier paper by Lynch and Schwaller from 2014, entitled ‘Mapping the Abundance and Distribution of Adélie Penguins Using Landsat-7: First Steps towards an Integrated Multi-Sensor Pipeline for Tracking Populations at the Continental Scale.’ It describes the development of an algorithm to analyse Landsat and high resolution imagery from WorldView-2 to estimate the size of penguin colonies based on the extent of the guana area. A classification approach was developed from a training dataset of 473 Landsat-7 pixels covering existing Adeline colonies, supported by over 10,000 pixels relating to features such as rock, soil and vegetation.

In the recently published paper, of which Heather Lynch was also a co-author, the team combined a range of imagery alongside some in-situ data to achieve their results. Different types of imagery were used:

  • High Resolution Imagery: Areas of guano staining on the Danger Islands were identified manually from WorldView-2 scenes.
  • Historical aerial photographs: Images taken by Falkland Islands Dependencies Aerial Survey Expedition (FIDASE) on the 31st January 1957 were digitally scanned and geo-referenced to the WorldView-2 data. They were then divided into polygons and analysed using manual classification processing using the open source QGIS software.
  • Landsat: The algorithm previously developed by Lynch and Schwaller was enhanced to work with data from Landsat-4, 7 and 8 by calculating the mean difference of similar bands from Landsat-4 and 8 compared to Landsat-7, and then adjusting based on the mean differences in each spectral band. The enhanced algorithm was then used to classify the penguin colony areas.
  • Drone data: Using a 1.2 megapixel camera flown at height of between 25 m and 45 m, captured footage was processed to produce georeferenced orthomosaics of the Danger Islands. Machine learning techniques were then applied using a deep neural network to locate and identify potential penguins. A training dataset of 160 images with 1237 penguins, followed by a validation dataset of 93 images with 673 penguins was used to teach the network. Once fully trained it analysed all the islands, and the results were validated with a number of manual counts. The scientists worked on an accuracy of plus or minus ten percent for the automated counts, although the variation with the in-situ counts was only 0.6 percent.

The outcome of this research was an identification of 751,527 pairs of previously unknown Adélie penguins on the Danger Islands. More surprisingly is that this increases the world estimates of this type of penguin by almost 50%, when it had been thought that the population had been declining for the last 40 years. The historical aerial imagery has led scientists to speculate that this new colony has remained constant for around the last 60 years in contrast to other known colonies.

This work is a great example of not only how much can be achieved with free-to-access imagery, but also how satellite imagery is helping us discover new things about our planet.

UK Focusing on Agri-tech

Agri-tech has long been seen as an exploitable opportunity for Earth Observation (EO). This was highlighted again last week by Greg Clark MP, the Business Secretary, at his speech at the National Farmers’ Union Conference in Birmingham where he announced a £90 million investment in the agri-tech sector specifically relating to EO, Artificial Intelligence and Robotics.

A definition of agri-tech can be the use of technology to improve agriculture production in terms of yield, efficiency and profitability. Despite all the innovations we’ve had in farming, according to the United Nations, there is still one in nine people in the the world undernourished.

In addition, UNESCO estimates that with the growing global population we’ll need sixty percent more food produced by 2050. Innovative and news ways of working within food production are going to be vital to deliver this level of increase. However, it’s a complex issue. Other critical factors include water demand from agriculture that is already expected to rise by 20% in the coming years, and the agriculture sector is also the largest employer in the world with almost forty percent of the world’s population dependent on it for their livelihoods.

The Government announcement last week recognised the importance of the agriculture industry within this country, as the sector employs four million people and provides £14.3 billion to the national economy. However, we were a little surprised to read that there are half a million jobs solely working in agri-tech in the UK.

The money announced is part of the Industrial Strategy Challenge Fund that was established last year to provide £4.7 billion for research and development to support the Government’s Industrial Strategy. It has a number of challenges and this one is part of Transforming Food Production: From Farm to Fork. Further details are expected, but they have indicated they’re looking to make food production more efficient, productive and sustainable, as well as bringing highly skilled jobs to rural areas and develop some of the exports the UK is likely to need post Brexit.

EO, Artificial Intelligence and Robotics all offer huge possibilities in this area, not only in the food production but also in reducing pollution, waste and land management. For us the EO area is very exciting, and we’ve been involved in the sector for some time. Pixalytics is currently involved in a project in Uganda to support farmers on Drought and Flood Mitigation, and this week Sam is in South America kicking off a project directly supporting rice and palm oil growers.

In addition locally to us, Cornwall has an active agri-tech hub helping small and medium-sized Cornish companies innovate in this sector with support from various academic institutes including Plymouth University who through its Sustainable Earth Institute have projects including robotic systems for automating manual picking operations, developing the manufacture and analysis of artificial soils and the expansion of hydroponic growing environments.

We’ll be keeping an eye on the next stage in this challenge, as we’re always looking for new EO projects and opportunities within agri-tech. If the Government is serious about its stated ambition to put the country at the forefront of this revolution, there should be exciting times ahead.

Monitoring Water Quality from Space

Algal Blooms in Lake Erie, around Monroe, acquired by Sentinel-2 on 3rd August 2017. Data Courtesy of ESA/Copernicus.

Two projects using Earth Observation (EO) data to monitor water quality caught our eye recently. As we’re in process of developing two water quality products for our own online portal, we’re interested in what everyone else is doing!

At the end of January UNESCO’s International Hydrological Programme launched a tool to monitor global water quality. The International Initiative on Water Quality (IIWQ) World Water Quality Portal, built by EOMAP, provides:

  • turbidity and sedimentation distribution
  • chlorophyll-a concentration
  • Harmful Algal Blooms indicator
  • organic absorption
  • surface temperature

Based on optical data from Landsat and Sentinel-2 it can provide global surface water mosaics at 90 m spatial resolution, alongside 30 m resolution for seven pilot river basins.  The portal was launched in Paris at the “Water Quality Monitoring using Earth Observation and Satellite-based Information” meeting and was accompanied by an exhibition on “Water Quality from the Space – Mesmerizing Images of Earth Observation”.

The tool, which can be found here, focuses on providing colour visualizations of the data alongside data legends to help make it as easy as possible to use. It is hoped that this will help inform and educate policy makers, water professionals and the wider public about the value of using satellite data from monitoring water resources.

A second interesting project, albeit on a smaller scale, was announced last week which is going to use Sentinel-2 imagery to monitor water quality in Scottish Lochs. Dr Claire Neil, from the University of Stirling, is leading the project and will be working with Scottish Environment Protection Agency. It will use reflectance measures to estimate the chlorophyll-a concentrations to help identify algal blooms and other contaminants in the waters. The project will offer an alternative approach to the current water quality monitoring, which uses sampling close to the water’s edge.

An interesting feature of the project, particularly for us, is the intention to focus on developing this work into an operational capability for SEPA to enable them to improve their approach to assessing water quality.

This transition from a ‘good idea’ into an operational product that will be used, and therefore purchased, by end users is what all EO companies are looking for and we’re not different. Our Pixalytics Portal which we discussed a couple of weeks ago is one of the ways we are trying to move in that direction. We have two water quality monitoring products on it:

  • Open Ocean Water Quality product extracts time-series data from a variety of 4 km resolution satellite datasets from NASA, giving an overview what is happening in the water without the need to download a lot of data.
  • Planning for Coastal Airborne Lidar Surveys product provides an assessment of the penetration depth of a Lidar laser beam, from an airborne survey system, within coastal waters based on the turbidity of the water. This ensures that companies who plan overflights can have confidence in how far their Lidar will see.

We’re just at the starting point in productizing the services we offer, and so it is always good to see how others are approaching the similar problem!

Celebrating Landsat & the Winter Olympics

First Landsat image acquired in 2013 showing area around Fort Collins, Colorado. Data courtesy of NASA/USGS.

The Landsat programme achieved a couple of significant milestones over the last two weeks. Firstly, the 11th February marked the five year anniversary of the launch of Landsat 8 which took place at the Vandenberg Air Force Base, California, in 2013. The image to the right is the first one acquired by Landsat 8 and shows the area around Fort Collins, Colorado with the Horsetooth Reservoir very clear left of centre.

This anniversary is an interesting one because Landsat 8 was only designed for an operational life of five years. Obviously it has already exceeded this and these planned lifespans are very conservative. More often the amount of fuel on board is a more relevant assessment for lifespan and for Landsat 8 the initial assessment was a 10 year lifespan. However, even this tends to be a conservative estimate. As an example, nineteen years ago Landsat 7 was launched with similar planned operational lifespans. It is still working today, although there have been some degradation issues, and IT achieved its own significant milestone on the 1st February when it completed its 100,000th orbit of the Earth.

Landsat 8 is in a sun-synchronous orbit at an altitude of 705 km, circles the Earth every 98.9 minutes and in the last five years has undertaken over 26,500 orbits according to NASA who have produced a short celebratory video.

It has two main instruments, an Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS), which together measure eleven different spectral bands. The TIRS has two thermal bands which are used for sensing temperature, whereas the OLI measures nine spectral bands:

  • Three visible light bands that approximate red, green and blue
  • One near infrared band
  • Two shortwave infrared bands
  • Panchromatic band with a higher spatial resolution
  • The two final bands focus on coastal aerosols and cirrus clouds.

With the exception of the highest polar latitudes, Landsat 8 acquires images of the whole Earth every 16 days which has meant it has acquired over 1.1 million images of the Earth that accounts for 16 percent of all the data in the Landsat multi-mission archive.

Landsat 8 image of Pyeongchang, South Korea, which is hosting the 2018 Winter Olympics. Data acquired 11th February 2018. Data courtesy of NASA/USGS.

The image to the left is the Pyeongchang region of South Korea where the Winter Olympics are currently taking place acquired by Landsat on its five year anniversary on the 11th February. Pyeongchang is in the north west of South Korea in the TaeBaek Mountains just over one hundred miles from the capital, Seoul. The left area of the image shows the mountain range where the skiing, biathlon, ski jumping, bobsled, luge and skeleton events take place and to the right is the coastal city of Gangneung, where the ice hockey, curling, speed skating and figure skating are taking place.

With its forty-five year archive, Landsat offers the longest continuous dataset of Earth observations and is critical to researchers and scientists. Landsat 9 is planned to be launched in 2020 and Landsat 10 is already being discussed.

Congratulations to Landsat 7 and 8, and we look forward to many more milestones in the future.

Flywheels Spinning At Data.Space

The Data.Space Conference took place last week in Glasgow. It was an interesting, thought-provoking and useful event, which felt very friendly and was distinguished by the seniority of the attendees with a lot of companies were represented by CEO’s, MD’s and owners/founders.

The event began with the session ‘Listening to our Earth’ with presentations from Spire, Hawkeye360, KSAT, CGI UK and Promos Ventures. We were particularly caught by the idea from Peter Platzer of Spire, who talked about the flywheel and how you need to build momentum within companies to move from good to great, in particular focussing on making a tenfold improvement on what currently exists.

Sam gave her presentation in the second session on ‘Looking at our Earth’, which can be accessed here. We found it encouraging that some of the key messages that we picked out were echoed by other presenters, both in this session and others. The common themes highlighted included:

  • Stop focussing on imagery, and focus more on customer needs.
  • Demonstrate the problem that the Earth Observation (EO) data solves and the value it adds.
  • The fact that the data comes from space isn’t critical to the customer.

We had a number of people come up after Samantha’s presentation to say how much they enjoyed it, which is always good! Interestingly, hers was not the only presentation that Pixalytics got mentioned in. Our blog on ‘Earth Observation Satellites in Space’ was name checked by Will Cadell, CEO of Sparkgeo, in the session after lunch. A highlight of which was Grega Milcinski, CEO Sinergise, demonstrating the possibilities of the Sentinel Hub and how they are making a lot of their code available on GitHub to enable others to build on it.

The second day began with a thought provoking session on using EO to create a better planet. Temporal resolution, file sizes, lack of internet facilities and the need to have quick simple maps was highlighted as a challenge to using EO data in disaster relief scenarios. Access to datasets was highlighted by Tony Long, Global Fishing Watch, as a barrier to providing a planet wide view of what is happening. It was also great to listen to Steve Lee from Astrosat talk about their experiences of two UK Space Agency International Partnership Programme projects, and pick up some pointers for the ones we’re involved in.

As a micro company, the second session of this day was fascinating to us giving an overview of what investors and venture capital people look for in companies. It was heartening to hear that data analytics is seen as having a lot of value, but less positive was that the vast majority of funding in this area is going into the US. It was also noted that these funders aren’t interested in funding research, they want to get in on the ‘Last Mile’ of a product or service – making us wonder whether we would ever be attractive to investors!

Pixalytics Stand at Data.Space

Throughout the conference we manned our small table, surrounded by companies with the obligatory pop-up banners. We stood alone bare backed as we flew to Glasgow on Easyjet and a pop-up banner would have been an extra bag! We had lots of interesting conversations over potential collaborations, new customers, product ideas and solutions to challenges; and we even managed to sell a couple of copies of our book! We were able to demonstrate our portal, and we got some really good feedback. We’ll be looking for more feedback and some beta testers over the coming weeks – please get in touch in you’re interested! Finally, we‘d also like to commend the fantastic food offering at the event, which had lots of lovely Scottish notes.

Overall, this was a great event and we’ll certainly be looking to go back next year!

Five Learning Points For Developing An Earth Observation Product Portal

Landsat mosaic image of the Isle of Wight. Data courtesy of NASA.

This week we’re gently unveiling our Pixalytics Portal at the DATA.SPACE 2018 Conference taking place in Glasgow.

We’ve not attended DATA.SPACE before, but great feedback from some of the last years attendees convinced us to come. It’s an international conference focusing on the commercial opportunities available through the exploitation of space-enabled data and so it seemed the perfect place to demonstrate our new development.

Regular readers will know we’ve had the product portal idea for a little while, but it often went to the back of the work queue when compared to existing work, bid preparation and our other developments. Hence, six months ago we pinpointed the DATA.SPACE as our unveiling event!

On the 1st and 2nd February at Technology & Innovation Centre in Glasgow we have a stand where we’re inviting everyone to come up and have a look at the portal and give us feedback on the idea, principles and the look and feel of the portal.

We’re demonstrating five products, and we’re looking to expand this, these are:

  • Landscape Maps of the UK
  • Water Extent Mapping
  • Flood Water Mapping
  • Coastal Airborne Lidar Survey Planning Datasets
  • Open Ocean Water Quality Parameters

We’re not just attending, we’re exhibiting and Sam’s presenting!! So we’re going to have the full triumvirate conference experience. Sam is presenting in the first day’s second session titled ‘Looking at our Earth’ which starts at 11.10am. Her presentation is called ‘Growing Earth Observation By Being More Friendly.’

Developing this portal to its current state has been a really interesting journey. When we began we didn’t know why some of the larger companies haven’t cracked this already! Six months later and we’ve started to understand the challenges!

We thought it might be helpful to reveal are five top learning points for any other SME’s in our industry considering developing a portal. They are:

  1. Challenging the Digital e-commerce Process: Standard digital e-commerce systems allow customers to purchase a product and then download it immediately. The need to have an additional step of a few minutes, or even hours, to undertake data processing complicates things. It means that simple off-the-shelf plug-ins won’t work.
  2. Don’t Go for Perfection: Building a perfect portal will take time. We’ve adopted the approach of Eric Ries, author of The Startup Way, who advocates building a system for ten purchases. We’re perhaps a bit beyond that, but certainly we know that this will only be the first iteration of our portal.
  3. Linking The Moving Parts: Our portal has a web-front end, a cloud processing backend and the need to download requested data. We’ve tried to limit the amount of data and processing needed, but we can’t eliminate it entirely. This means there are a lot of moving parts to get right, and a lot of error capturing to be done!
  4. Legal & Tax issues: Sorting out the products is only one part of the process, don’t forget to do the legal and tax side as that has implications on your approach. We have learnt a lot about the specific requirements of digital services in e-commerce!
  5. Have a deadline: We chose to exhibit at DATA.SPACE to give us a deadline. We knew if we didn’t have a hard deadline we’d still be debating the products to include, and have developed none of them! The deadline has moved us really close to having a portal.

If you’re at DATA.SPACE this week, please come up and say hello. If you’ve got a few minutes to spare we’d love to get you feedback on our portal.

First Light Images

Mosaic image of The Netherlands created using three Sentinel-1 scans in March 2015.
Data Courtesy of Copernicus Sentinel data (2015)/ESA.

Two of the satellites launched on 12th January by the Indian Space Research Organization (ISRO) have released their first images. We wrote about the launch two weeks ago, and wanted to follow up on their initial outputs.

The first is the exciting ICEYE-X1, which is both the world’s first synthetic-aperture radar (SAR) microsatellite and Finland’s first commercial satellite. We currently use Sentinel-1 SAR imagery for some of Pixalytics flooding and water extent mapping products and so are really interested to see what this satellite produces.

One of the key advantages of radar satellites over optical ones is that they can capture images both during day and night, and are not hampered by the presence of clouds.  However, using a different part of the electromagnetic spectrum to optical satellites means that although it is black and white image it’s sometimes easier to distinguish objects within it.

Zoomed in portion of Netherlands mosaic image created using three Sentinel-1 scans in March 2015.
Data Courtesy of Copernicus Sentinel data (2015)/ESA.

For example, the image to the left is a zoomed in portion of Sentinel-1 mosaic of the Netherlands acquired in March 2015 where you can clearly see couple of off-shore windfarms.

Sentinel-1 is a twin satellite constellation and uses a C-Band SAR on board two identical satellites. Over land it captures data in an Interferometric Wide swath mode, which means it takes three scans and then combines them into a single image. Each scan has a width of 250 km and a spatial resolution of 5 m x 20 m, with a six day repeat cycle for an area of land.

In comparison, ICEYE-X1 produced its first image with a spatial resolution of 10 m, and it’s hoped to reduce this down to 3 m. It issued its first image on Monday 15th January, three days after launch, showing part of Alaska, including the Noatak National Preserve, with a ground coverage of approximately 80 km by 40 km. The image can be seen here.

ICEYE-X1 weighs in at under a 100 kg, which is less than a twentieth of Sentinel-1 which weighed in at 2 300kg. This size reduction produces a high reduction in the cost too, with estimates suggesting it only cost ICEYE around a hundredth of the €270 million price of the second Sentinel-1 satellite.

By 2020 ICEYE is hoping to establish a global imaging constellation of six SAT microsatellites that will be able to acquire multiple images of the same location on Earth each day. After this, the company has ambitions of launching 18 SAR-enabled microsatellites to bring reliable high temporal-resolution images which would enable every point on the Earth to be captured eight times a day.

Cartosat-2F also sent its first image on the 15th January. The image, which can be found here, is of the city of Indore, in the Indian state of Madhya Pradesh. The Holkar Stadium is tagged in the centre, a venue which has previously hosted test Cricket. The satellite carries a high resolution multi-spectral imager with 1 m spatial resolution and a swath width of 10 km.

It is the seventh satellite in the Cartosat series which began in 2007, the others are:

  • Cartosat 2 launched on 10th January 2007
  • Cartosat 2A launched on 28th April 2008
  • Cartosat 2B launched on 12th July 2010
  • Cartosat 2C launched on 22nd June 2016
  • Cartosat 2D launched on 15th February 2017
  • Cartosat 2E launched on 23rd June 2017

These two satellites are just at the start of their journey, and it will be interesting to see what amazing images they capture in the future.

EO Market Is a-Changin’

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

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

Historically, if you wanted satellite Earth Observation (EO) data your first port of call was usually NASA, or NOAA for meteorological data, and more recently you’d look at the European Union’s Copernicus programme. Data from commercial operators were often only sought if the free-to-access data from these suppliers did not meet your needs.
However, to quote Bob Dylan, The Times They Are a-Changin’. NASA, NOAA and Copernicus are buying, or intending to buy, data from commercial operators.

However, as with many activities there are often precedents. For example, the SeaWiFS mission was built to NASA’s specifications and launched in 1997. It was owned by the commercial organisation Orbital Sciences Corporation and NASA conducted a ‘data-buy’. They’ve moved back in this direction last month as NASA issued a Request for Information for US companies interested in participating in the Earth Observations from Private Sector Small Satellite Constellations Pilot. The aim of this programme is to identify commercial organisations collecting EO data relating to Essential Climate Variables (ECV), and then to evaluate whether this would be a cost effective approach to gathering data rather than, or alongside, launching their own satellites.

To interest NASA the companies need to have a constellation of at least three satellites in a non-geostationary orbits, and the ECV dataset will need to include details of both instrument calibration and processing techniques used. Initially, NASA plans to provide this data to researchers to undertake the evaluation. According to Space News, 11 responses to the request had been received. Discussions will take place with responding companies over the next month and it’s anticipated orders will be placed in March 2018.

NOAA is another US agency looking to the private small satellite sector through their Commercial Weather Data pilot programme. To supplement their own data collections they’ve already purchased GPS radio occupation data and are planning to buy both microwave sounding and radiometry data.

Not everyone is aware that the Copernicus Programme also purchases data from commercial sources as part of its Contributing Missions Programme. Essentially, if data is not available for any reason from the Sentinel satellites, then the equivalent data is sought from one of 30 current contributing missions which include other international partners such as NASA, but also commercial providers.

Whilst part of the drive behind this approach is to ensure data continuity, in the US the backdrop has a more long term concern with President Trump’s intention to move NASA away from EO to focus efforts on deep space exploration. It’s not been fully confirmed yet, but there is due to be a Congress budget discussion later this week and if approved it could mean the loss of the following four NASA missions:

• Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) satellite
• Orbiting Carbon Observatory-3 (OCO-3)
• Climate Absolute Radiance and Refractivity Observatory (CLARREO) Pathfinder
• Deep Space Climate Observatory (DSCOVR)

Whilst buying data from commercial providers may offer opportunities, it also has a number of challenges including how to buy this whilst maintaining their commitment to free-to-access data, and with the shorter lifespans of small satellites the increased pressure on calibration and validation work.

It’s clear that things are evolving in the EO market and the private sector is coming much more to the fore as a primary data supplier to researchers, national and international bodies.