History Comes Around

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

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

Remote sensing is a relatively young industry, but it doesn’t mean we don’t have history. We do. We shouldn’t it, and were reminded why this week as we bounced back through time.

We noticed an introductory tweet yesterday from the Earth Resources Observation and Science Centre (EROS) History Project established by the US Geological Survey. This project has created an amazing online archive of information about its involvement in remote sensing that contains documents, and videos, from 1960s/70s to the current day. A few of the archive items that caught our attention were:

News Release from United States Department of the Interior on the 21st September 1966 with the title ‘Earths Resources To Be Studied From Space’. What struck us was how the phrases could be from today.

  • ‘gathering facts about the natural resources of earth’
  • ‘the time is now right and urgent to apply space technology towards the solution of many pressing natural resources problems being compound by population and industrial growth’
  • ‘An opportunity to collect valuable resource data and use it to improve the quality of our environment’

Equally, the sessions from 1973 Management & Utilization of Remote Sensing Data Symposium, organized by the American Society of Photogrammetry, could easily be describing a current conference:

  • Role of Remote Sensing in Resource Management & Planning
  • Hydrological and Environmental Applications
  • Future Sensor and Information Handling Systems
  • Agricultural and Forestry Applications

We loved the 1980 User Frustrations with Landsat, which noted data quality issues like:

  • Desert scenes have no contrast
  • There’s no underwater detail in the image
  • The image is striped!

A reminder in the news release from 15 March 1989 on how close the world came to losing the Landsat archive. This release rescinded the order, made two weeks earlier, to shutdown Landsat 4 & 5 and to provide funding until a policy review of Landsat could be completed.

The archive is a wealth of interesting details about the history of US remote sensing, including the amount of data collected over the years to the more mundane, but no less fascinating, descriptions of the furniture required to set up EROS in the first instance! We’d highly recommend you have a look at this archive – although be warned, I lost a few hours in there whilst writing this blog!!

This week is also a big anniversary for Landsat-1 which was launched on the 23rd July 1972, and the first satellite image from it was received on the 26th July 1972 beginning the 44 year archive. It’s also the Landsat Science Team’s 2016 Summer meeting this week in South Dakota, and amongst the topics of discussion are future sensor capabilities for Landsat 10 – showing not much has changed from 1973!

Although remembering the past is important, it’s vital that we also look forward to the future. At the Landsat Science Team meeting, it was noted the target launch date for Landsat 9 is the 15th December 2020, and as discussed above they are already talking about Landsat 10!

Gliding Across The Ice

ESA’s Earth Explorer CryoSat. Image courtesy of ESA/AOES Medialab.

ESA’s Earth Explorer CryoSat. Image courtesy of ESA/AOES Medialab.

There’s been a flurry of reports in the last couple of weeks, reporting melting ice and retreating glaciers in Greenland and the Himalayas respectively.

A paper by McMillan et al (2016), titled ‘A high-resolution record of Greenland mass balance’ and published in Geophysical Research Letters earlier this month, highlighted that Greenland’s melting ice has contributed twice as much to sea level rise than in the previous twenty years. The research used CryoSat-2 radar altimetry between 1 January 2011 and 31 December 2014 to measure elevation changes in the Greenland ice.

The main instrument on ESA’s CryoSat-2 satellite is a Synthetic Aperture Radar (SAR)/Interferometric Radar Altimeter known as SIRAL, although also carries a second version of this instrument as a back-up. The SIRAL instrument has been enhanced to detect millimetre changes in the elevation of both ice-sheets and sea-ice. It sends out bursts of radar pulses, with an interval of 50 μs between them, covering a 250 m wide strip of the Earth and measures the time of the return signal to determine the height of the satellite above the Earth. It requires a very accurate measurement of its position to calculate this, and so it also carries a Doppler Orbit and Radio Positioning Integration by Satellite (DORIS) instrument to determine its orbit.

The research team discovered that the Greenland Ice Sheet lost an average of 269 ± 51 Gt/yr of snow and ice during the investigative period, which compared well with other independent measurements from sensors such as the Gravity Recovery and Climate Experiment (GRACE) satellite and results from climate models. This snow and ice loss corresponds to a 0.75 mm contribution to global sea-level rise each year.

It was reported this week that research undertaken by the Indian Space Research Organisation, Wadia Institute of Himalayan Geology and other institutions have revealed that the majority of the glaciers in India are retreating; albeit at different rates. Using remote sensing data up to 2006, the study looked at 82 glaciers in the Bhagirathi and Alaknanda river basins and found that there had been an overall loss of 4.6% of the glaciers within the region. The Dokriani glacier in Bhagirathi is retreating between 15 and 20 metres per year since 1995, whereas the Chorabari glacier in the Alaknanda basin is retreating 9-11 metres per year.

It’s interesting to read the retreating glacial picture alongside the research published by Schwanghart et al (2016), titled ‘Uncertainty in the Himalayan energy–water nexus: estimating regional exposure to glacial lake outburst floods’, in Environmental Research Letters. Here the research team completed the first region wide risk assessment of floods from glacial lakes, even though this only covered around a quarter dams in the Himalaya’s. The study mapped 257 dams against more than 2,300 glacial lakes within the region and found that over 20% of the dams are likely to be overwhelmed with flood water as rock systems that surround glacier-fed lakes fail. Due to the hydro-electric power needs of the region, more dams have been built in recent years, putting them closer to glacier-fed lakes.

The potential danger of this issue is demonstrated by the collapse of Zhangzangbo, a glacier-fed lake in southern Tibet, in 1981 where 20 million cubic meters of floodwater damaged hydroelectric dams and roads causing damage of approximately $4 million.

These three reports also show the potential danger melting ice and glaciers pose both locally and globally. Remote sensing data, particularly from satellites such as CryoSat-2, can help us monitor and understand whether this danger is increasing.

Remote Sensing and the DIKW Pyramid

DIKW PyramidSatellite remote sensing industry is evolving and anyone working in it needs to become familiar with the Data, information, Knowledge, Wisdom (DIKW) pyramid as this is one map, albeit simplistic, of the industry’s and our current journey.

Historically, satellite data was either sold as the original image or with a small amount of processing undertaken. If anyone wanted to do anything beyond basic processing, they had to do it themselves. However, things are changing.

According to a recent Euroconsult report, at least 3,600 small satellites will be launched over the next decade. The United Nations Office on Outer Space Affairs only lists 7,370 objects that have ever been launched into space, of which only 4,197 are still in orbit. We’re increasing the number of objects orbiting the Earth by 85% by smallsats alone, larger satellites will add even more.

The volume, variety and speed of this data collected by these satellites will present a step change not only in the type of applications companies will be able to offer, but, crucially, also in customer expectations – more and more they will be looking for added value.

One way of considering this is through the DIKW pyramid, which can be seen at the top of the blog, it’s credited to American organisational theorist Russell Ackoff in 1989, building on the ideas of Milan Zeleny two years earlier.

A simple summary of the pyramid starts with the collection of data which means nothing in its own right, it is simply data. Information is derived from data by asking the who, what, where, when and how questions. Knowledge is information to which expert skills and experience have been added to create more value – which is more profitable in a business context. Finally, wisdom is understanding what actions to take based on the knowledge you’ve gained.

Applying this to satellite remote sensing for agriculture, one example might be: data is the satellite data/image of the field. Information is knowing when the image was taken leading to where in the growing cycle the crop was. Knowledge is applying scientific algorithms to know the soil moisture, how much nutrients are in the soil or how much vegetation is present in various parts of the field. Wisdom is knowing what nutrients and fertilizers to apply, based on the knowledge gained, to improve crop yields.

A lot of Earth observation products are at the data or information level, with a few at the knowledge level, and even fewer at the wisdom level. Customers more and more want wisdom products, and they aren’t that interested in what was required to create them. When you add to this the additional types of geospatial information, e.g., optical and radar used together alongside airborne and in-field ground based measurements, the variety of open datasets and the new science and technological breakthroughs, things are going to look very different, very quickly.

We’d accept that the DIKW isn’t a perfect tool, nor a perfect representation of our industry, but it is simple, indicative and worth thinking about. We wrote about our intention to create products in an earlier blog. We’re a long way from the wisdom sector, but are hoping to be firmly within the knowledge sector and collaborating to create wisdom. It’s not easy and some companies will find it harder to do than others, but is going to be the future. How are you preparing?

Beijing Is Sinking

Envisat's ASAR sees Tianjin, China's third largest city.  Image courtesy of ESA.

Envisat’s ASAR sees Tianjin, China’s third largest city. Image courtesy of ESA.

Last month a paper was publishing in the Remote Sensing journal demonstrating that the city of Beijing is gradually sinking as a result of subsidence.

The paper ‘Imaging Land Subsidence Induced by Groundwater Extraction in Beijing (China) Using Satellite Radar Interferometry’ by Chen et al described work undertaken by a team of researchers using satellite images from between 2003 and 2011.

The research was undertaken using Interferometric Synthetic Aperture Radar (InSAR), which is a microwave based technique that uses phase measurements from two or more successive satellite SAR images to determine the Earth’s shape and topography and so to measure millimetre-scale changes.

The study used 41 images from Envisat-ASAR acquired from 2003 to 2010 collected in Stripmap mode with VV polarisation, together with 14 images from TerraSAR-X acquired from 2010 to 2011 also in Stripmap mode, but this time using HH polarisation. The images were processed alongside some baseline interferograms and the Shuttle Radar Topography Mission (SRTM) Digital Elevation Model, at 90 m resolution, to produce land subsidence information. The results showed that parts of Beijing, such as the business district of Chaoyang, had sunk by as much as 11 cm within a year. In addition, they estimated that parts of the city had sunk by more than 75cm during the course of the eight year study period.

Land subsidence is often caused by human activities and the researchers identified the main cause to be the extraction of groundwater from beneath the city. Beijing has an enormous appetite for water and is the fifth most water-stressed city in the world according to a 2014 report published by the Nature Conservancy. However, the amount of groundwater extracted was not the only factor with the researchers also seeing relationships with soil type, aquifer type and distance to the pumping wells. In addition, given the number of buildings that have been erected in Beijing in the last fifteen years the additional weight is also likely to be contributing to the problem.

This sinking is not noticeable to the inhabitants of Beijing, but there is concern how this subsidence will impact the transport infrastructure, particularly high speed trains and research is already underway on this area. It is also not just Beijing that’s suffering from subsidence. The research also identified 45 other areas across China as having had or having significant land subsidence. In addition, Mexico City is sinking by between 6 cm and 28 cm per year and the Indonesian capital of Jakarta has dropped by around 8 cm per year; both are due to groundwater extraction. Even London is sinking, although in our case it only 1 – 2 millimetres per year!

Water is a precious resource and one that is necessary for growing populations and economies alike. Research such as this demonstrates why the world needs to get better at water conservation. If we continue as we are, there could be potentially serious consequences for parts of the globe.

Brexit and the Earth Observation Market

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Pixalytics
We have a variety of strong European links including:

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

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

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

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

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

Pixalytics Four Year Celebration!

Sutichak Yachaingham / 123 Stock Photo

Sutichak Yachaingham / 123 Stock Photo

The start of June marked the four-year anniversary of Pixalytics! We’d not realised that the time of year had come around again until Sam started receiving messages via her LinkedIn profile. A lot of small business owners are like us, busy working with their head down and they forget to look up and celebrate their successes and milestones.

So, although we had to be prompted to look up, we’re going to celebrate our milestone of Pixalytics thriving – or maybe surviving – for four years!

The last twelve months have been really successful for us, with the main highlights:

  • Doubling our company turnover.
  • Appointing our first additional full-time employee.
  • Having our book, Practical Handbook of Remote Sensing, published and being sold.
  • Winning a Space for Smarter Government Programme contract.
  • Expanding our EO products and services into AgriTech & flood mapping.
  • Being short-listed for the Plymouth Herald Small Business of the Year Award.
  • Being short-listed for the European Association of Remote Sensing Companies (EARSC) European EO Services Company Award.
  • Hosting two ERASMUS placements and other work experience students.

We wrote a blog last June identifying what we were hoping to achieve in the coming twelve months. The key things were developing our customer base, products, and services together with employing someone else full time. Those aims were definitely achieved!

Well, that’s enough of the celebrating! Like any other small business we’re much more interested in what’s in our future, than our past. We’ve still got plenty of challenges ahead:

  • Doubling our turnover was a big leap, and this year we’ve got to maintain that level and ideally grow more.
  • Despite having additional hands in the business, we still have more ideas than capacity. Some of the ideas we had last year have been taken forward by other companies, before we’ve had the chance to get around to them! We wish them success and will be watching with interest to see how they develop.
  • Marketing is hard work. None of us at Pixalytics are marketing experts, and it’s clear to us the difficulty of competing with firms who have sales and marketing teams promoting themselves at conferences and events. Our current approach is a combination of social media, and picking the events to attend. Both Sam and I are promoting Pixalytics this week, and then it’s back to the office next week to welcome our summer Space Placements in Industry (SPIN) student.

Our key target for the end of this year is to release an innovate series of automated Earth observation products and services that we can sell to clients across the world – we started to describe this journey here. We know we’ll be competing with companies much bigger than us and we know it’s not going to be easy, and to revisit the Samuel Beckett quote we used last year:

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

It still holds true for how we run our company. We try things. We fail. We succeed. We learn. We try new things.

We’re looking forward to what the next twelve months, or four years, have in store.

Uncovering Secrets with Remote Sensing

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

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

Recent significant discoveries in Cambodia and Jordan have highlighted the potential offered by remote sensing and satellite imagery to help uncover secrets on Earth – a field known as satellite archaeology.

Cambodia
Helicopter mounted Lidar was used to reveal multiple cities beneath the forest floor near the ancient temples of Angkor Wat in Cambodia. Lidar, which stands for Light Detection and Ranging, is an active optical remote sensing technique that uses a laser scanner to map the Earth’s topography by emitting a laser pulse and then receiving the backscattered signal. In Cambodia, a topographic Lidar with a near infrared laser was used by Australian archaeologist Dr Damian Evans to survey beneath the forest vegetation.

The conurbations discovered, surrounding the stone temple Preah Khan Kompong Svay, are believed to be between 900 to 1 400 years old. Analysis of the survey has shown a large number of homes packed together liked terraced houses, together with structures for managing water and geometric patterns formed from earth embankments – which could be gardens.

At 734 square miles, the 2015 survey is also thought to be the most extensive of its type ever undertaken. Dr Evans work is due to be published in the Journal of Archaeological Science.

Jordan
Archaeologists using high resolution satellite imagery, drones surveys and imagery within Google Earth have discovered a huge structure buried in the sand less than a kilometre south of the city of Petra. The two high resolution satellites used were Worldview-1 and Worldview-2, operated by DigitalGlobe. Worldview-1 was launched in September 2007 and has a half-metre panchromatic resolution; Worldview-2, launched two years later, offers similar panchromatic resolution and 1.85m multispectral resolution.

The outline of the structure measures 56m x 49m, and there is a smaller platform contained inside the larger one. Nearby pottery finds suggest the platform is 2 150 years old, and it is thought that it had a ceremonial purpose. The research undertaken by Sarah Parcak and Christopher Tuttle was published in the May 2016 edition of the Bulletin of the American Schools of Oriental Research.

Benefits of Remote Sensing & Satellites
Angkor Wat and Petra are both World Heritage sites, and the benefits of using remote sensing and satellite technology to undertake archaeological investigations are evident in the statement from Christopher Tuttle who noted that they did not intend to excavate their Petra discovery as ‘The moment you uncover something, it starts to disintegrate.’

Satellite technology allows investigations to take place without disturbing a piece of soil or grain of sand, which is a huge benefit in terms of time, cost and preservation with archaeology. These two discoveries also demonstrate that the world still has secrets to reveal. As Sarah Parcak herself said in 2013, “We’ve only discovered a fraction of one percent of archaeological sites all over the world.”

Who knows what remote sensing and satellite imagery will uncover in the future?

Monitoring ocean acidification from space

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

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

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

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

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

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

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

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

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

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

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

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

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

Playboy Magazine & Remote Sensing

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

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

Are you aware the role Playboy Magazine has had in the remote sensing and image processing industries? Anyone who has read a selection of image processing books or journals will probably recognise the Lena picture as a standard test image. If you don’t know the image, you can find it here. Lena’s history is interesting.

It began in 1973 when Alexander Sawchuk, who was then an assistant professor at the USC Signal and Image Processing Institute, was part of a small team searching for a human face to scan for a colleague’s conference paper. They wanted a glossy image to get a good output dynamic range and during the search someone walked in with the November 1972 issue of Playboy. They used the centrefold image, the Swedish model Lena Söderberg, so they could wrap it around the drum of their scanner. As they only needed a 512 x 512 image, they scanned the top 5.12 inches of the picture, creating a head shot rather than the original full nude centrefold.

From this beginning Lena, often called Lenna as this was the forename used in Playboy, has gone to be one of the most commonly used standard test images. There are a number of theories of why this is the case, including:

  • The image has a good variety of different textual elements, such as light and dark, fuzzy and sharp, detailed and flat.
  • The grayscale version contains all the middle grays.
  • She has a symmetrical face, making any errors easy to see.
  • The image processing community is predominantly male!

Most often the image is used for compression testing, but has also used been used in the analysis of a wide variety of other techniques such as the application of filtering for edge enhancement. Even as recently as three years ago a group of scientists from Singapore shrunk the Lena image down to the width of a human hair as a demonstration of nanotechnology printing.

The wide use of Lena eventually came to the notice of Playboy, after the magazine Optical Engineering put her on their front cover in 1991. The Playboy organisation then tried to assert their copyright, however the genie was out of that bottle given the sheer number of people using it. The following year Optical Engineering reached an agreement with Playboy to continue using the image for scientific research and education. The copyright issues are why we didn’t include the Lena image on the blog, although has been reported that Playboy now overlook the use of the Lena for image processing we decided not to risk it! Playboy did help in the search for Lena in 1997 which enabled her to make a public appearance at the 50th Annual Conference of the Society for Imaging Science in Technology. An article written by Jamie Hutchinson giving a more detailed version of the Lena story can be found here.

What’s interesting about Lena is that despite all the technological advancements in the last forty years, she is still used as a standard testing image. Contrast this with the famous Blue Marble image of the Earth taken around the same time by astronauts aboard Apollo 17. The 1972 Blue Marble is probably the most iconic picture of the Earth, and unlike Lena has inspired numerous later images. For example, NASA used the Terra satellite to produce a detailed true-colour image of the Earth in 2002 and then three years later surpassed it with a new image that had twice as much detail as the original. The latest NASA Blue Marble was issued last year, captured by the US DSCOVR Earth observation satellite.

Standard test images are important, but the image processing community should probably start to think about updating the ones we use. Anyone got any ideas?

Simplification in the Geospatial Industry

GEO Business 2016 at Business Design Centre, London.

GEO Business 2016 at Business Design Centre, London.

It’s May which means it’s GEO Business time at the Business Design Centre in London. Last year Pixalytics used this event to dip our collective toe into exhibiting, and this year we’ve decided to be the other side and are attending as participants. Louisa and I are here to catch up with what’s happening in the geospatial industry through the conference presentations, the workshop programme and visiting the exhibition stands.

I attended the first conference session which began with a keynote from Tom Cheesewright, Applied Futurist, which highlighted the importance of location in bringing together the physical and digital world. This led into a presentation from Ed Parsons, Geospatial Technologist from Google, which discussed the changing face of this industry. In particular, he discussed the importance of ensuring we simplify our interfaces so users don’t have to know the detail of how things work, and are only provided with relevant information they want.

Gary Gale from What3Words applies this simplification approach to positioning. In his presentation he argued that address based systems aren’t unique and coordinate systems aren’t easy for people to understand. Therefore, What3Words have proposed a naming system whereby every 3 metre square on the Earth, is referenced by just three words. For example, the Business Design Centre has a position of begins.pulse.status under this system.

A third presentation in this session was given by Prof. Gianvito Lanzolla, from Cass Business School, and discussed what business models may look like in the future. He explained that digitization leads to connectivity and reminded everyone that phones and cameras only converged in 2002. This change is now moving into data, where connected products are becoming increasingly important: with trust and speed being key attributes.

The panel debate discussed the importance of disruptors for driving innovation forward, and that markets mature over time so that only the best offerings remain. There were also thoughts on privacy as people are happy to provide locational information when they wanted a service to know where they are, but that future services need to focus on the location of the individual rather than their provided address.

This theme of simplification and ensuring that products are fit for purpose was picked up in the post-lunch session where John Taylor, from the Land Registry, described how the MapSearch product for deeds was developed. Instead of trying to develop a complex interface with all possible features, they started with a stripped down Minimum Viable Product. John highlighted the importance of discussing the solution with the users at every iteration, making sure the features included were wanted and would be used. This approach resulted in a 65% reduction in manual searches, which has reduced staff costs and saved money for customers as the manual search for deeds was charged, whilst MapSearch is available for free.

Walking around the exhibition provided a good opportunity to catch up with colleagues, and see what was trending. It was noticeable that instrumentation was accompanied by what felt like an increased percentage of stands linked to UAVs (or drones) and data analysis / web mapping companies.

As usual with conferences my head is buzzing with ideas and things to take back to Pixalytics. In a recent blog we discussed the start of our journey to develop our own products and services, and the themes of simplification and fit for purpose are certainly going to feed into our thinking!