3 Ways Earth Observation is Tackling Food Security

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

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

One of the key global challenges is food security. A number of reports issued last week, coinciding with World Food Day on the 16th October, demonstrated how Earth Observation (EO) could play a key part in tackling this.

Climate change is a key threat to food security. The implications were highlighted by the U.S. Geological Survey (USGS) report who described potential changes to suitable farmland for rainfed crops. Rainfed farming accounts for approximately 75 percent of global croplands, and it’s predicated that these locations will change in the coming years. Increased farmland will be available in North America, western Asia, eastern Asia and South America, whilst there will be a decline in Europe and the southern Great Plains of the US.

The work undertaken by USGS focussed on looking at the impact of temperature extremes and the associated changes in seasonality of soil moisture conditions. The author of the study, John Bradford said “Our results indicate the interaction of soil moisture and temperature extremes provides a powerful yet simple framework for understanding the conditions that define suitability for rainfed agriculture in drylands.” Soil moisture is a product that Pixalytics is currently working on, and its intriguing to see that this measurement could be used to monitor climate change.

Given that this issue may require farmers to change crops, work by India’s Union Ministry of Agriculture to use remote sensing data to identify areas best suited for growing different crops is interesting. The Coordinated Horticulture Assessment and Management using geoinformatics (CHAMAN) project has used data collected by satellites, including the Cartosat Series and RESOURCESAT-1, to map 185 districts in relation to the best conditions for growing bananas, mangos, citrus fruits, potatoes, onions, tomatoes and chilli peppers.

The results for eight states in the north east of the country will be presented in January, with the remainder a few months later, identifying the best crop for each district. Given that India is already the second largest producer of fruit and vegetables in the world, this is a fascinating strategic development to their agriculture industry.

The third report was the announcement of a project between the University of Queensland and the Chinese Academy of Sciences which hopes to improve the accuracy of crop yield predictions. EO data with an improved spatial, and temporal, resolution is being used alongside biophysical information to try to predict crop yield at a field scale in advance of the harvest. It is hoped that this project will produce an operational product through this holistic approach.

These are some examples of the way in which EO data is changing the way we look at agriculture, and potential help provide improved global food security in the future.

World Record Satellite Launch

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

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

Next week the Indian Space Research Organisation (ISRO) plans to launch 104 satellites in one go aboard its Polar Satellite Launch Vehicle (PSLV-C37) that will take off from Satish Dhawan Space Centre in Sriharikota, India.

To give an idea of the enormity of what ISRO is attempting, the current world record for satellites launched in a single mission is 37 by Russia in 2014. In addition, over the last fifty years the average number of objects launched in space in an entire year is only 138, according to the Online Index of Objects Launched into Outer Space maintained by the United Nations Office for Outer Space Affairs (UNOOSA). Furthermore these figures reveal this single mission will exceed the number of objects launched into space for the twelve months of 1996 and for the years 2001 to 2006 inclusive.

This mission was originally planned to launch 83 satellites, then an additional 20 were added to the payload and finally a further nano-satellite was squeezed in. Of these 104 satellites, 3 will be Indian satellites and the remainder will be small satellites from countries including Germany, Israel, Kazakhstan, Netherlands, Switzerland, and the US.

One of the key challenges is to ensure that they do not collide. ISRO plans to achieve this by changing the degree of angle for each batch of satellites launched. It is expected that the entire batch of satellites will be launched within 90 minutes.

This launch is a really exciting one for the Earth Observation community because it includes:

  • Cartosat 2D is the next satellite in India’s Cartosat mission. These satellites carry both high resolution multi- spectral imagers and a panchromatic camera, and the mission focus is cartography. It has a sub-metre spatial resolution, a 10 km swath and a revisit period of four days. This is the primary payload, and will be the heaviest satellite on the launch vehicle at 730 kg.
  • Planet’s Flock 3p which consists of 88 satellites, and will be the largest constellation of satellites ever launched.

Planet was in the news last week as it confirmed it had completed the purchase of satellite imaging company Terra Bella from Google. Terra Bella’s SkySat’s fleet of high resolution satellites will complement the existing global coverage of Planet’s existing courser resolution fleet. When combined with the new satellites, this will help Planet to achieve their aim of imaging the entire globe every day. Thereby, offering a wide range of potential capabilities for Planet in the satellite data reseller/supplier market.

ISRO’s launch is currently scheduled for February 15th and will demonstrate a new level of efficiency for cubesats; something that is becoming increasingly important. We’ll be watching closely, and wish them luck.

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.