Notes from the Field

Unraveling the Mysteries of Arctic Greening and Browning

October 5th, 2021 by Logan Berner and Patrick Burns (Northern Arizona University), and Roman Dial (Alaska Pacific University)

To better understand impacts of climate change on vegetation in the Alaskan Arctic, researchers will link long-term NASA satellite observations with ecological field data collected while trekking through the Brooks Range in northern Alaska. Photo by Roman Dial.

Following caribou and brown bear trails when possible, a small NASA-supported research team trekked 800 miles across Alaska’s Brooks Range last summer. With additional support from NSF, the Alaska Space Grant Program, and the Explorers Club/Discover, the research team is collecting extensive ecological field data that will be linked with satellite observations to better understand long-term changes in vegetation, including impacts of climate warming. The Arctic is warming nearly twice as rapidly as the rest of the planet and the impacts are becoming increasingly evident as glaciers melt, permafrost thaws, and tundra greens.

Arctic greening and browning

Earth-observing satellites have detected widespread increases in tundra greenness in the Arctic over the last four decades. The phenomena is caused, in part, by increases in vegetation growth as summers have become warmer and longer, and has been termed “Arctic greening.” On the other hand, satellite observations have also detected localized declines in tundra greenness attributed to surface flooding, extreme weather, and other disturbances. This has been termed “Arctic browning.” Satellite observations of greening and browning show that extensive changes are occurring in the Arctic, but much remains unclear about why specific regions have greened or browned in recent decades.

Earth-observing satellites have detected Arctic tundra becoming greener in recent decades as the growing seasons became warmer and longer. Landsat satellite observations indicate that about 22% of the Arctic became greener from 2000 to 2016, while 5% became browner. Adapted from Berner et al. (2020).
The team

To better understand recent greening and browning in northern Alaska, Professor Roman Dial’s team from Alaska Pacific University (APU) has been collecting extensive ecological observations while trekking throughout Alaska’s Brooks Range. For nearly forty years, Dial has studied and traversed the Alaskan wilderness, including nearly 2,000 miles by foot and packraft throughout the Brooks Range during the last three field seasons. For 11 days last summer, Dial’s team was joined by Dr. Logan Berner and Patrick Burns who are research ecologists from Northern Arizona University (NAU) and members of NASA’s Arctic-Boreal Vulnerability Experiment (ABoVE). While Dial is an expert in field ecology and wilderness travel, Berner and Burns are experts in satellite remote sensing and ecological informatics. By combining their expertise, these researchers hope to shed light on the extent, nature, and causes of vegetation changes during recent decades in the Brooks Range.

Pixel walking team (left to right) Logan Berner, Patrick Burns, Ben Weissenbach, Julia Ditto, Madeline Zietlow, Russell Wong. Photo by Roman Dial.
Trekking through the Brooks Range

The Brooks Range forms a natural barrier that separates the boreal forest of Alaska’s interior from the arctic tundra of Alaska’s North Slope. This mountain range includes the largest complex of protected wilderness in the United States, including 21,000,000 acres among the Arctic National Wildlife Refuge, Noatak National Preserve, and Gates of the Arctic National Park. Berner and Burns joined Dial’s research team as they trekked from the northern edge of boreal forest into the Noatak Wilderness where trees give way to thickets of shrubs, wetlands, and barren rocky ridges. During the course of 11 rain-soaked days, the team followed caribou and brown bear trails through verdant valley bottoms and over cloud-choked mountain passes as they traversed about 80 miles from the Ambler River to the Cutler River. While trekking, the researchers collected ecological field data to be linked with measurements of vegetation greenness from NASA Earth-observing satellites.

Route traveled by researchers during an 11-day segment of a summer-long trek through the western Brooks Range in northern Alaska. The orange route corresponds to off-trail foot travel, while the blue route corresponds to a combination of foot and raft travel. Image by Patrick Burns.

Roman, Logan, and Pat. Photo by Ben Weissenbach.

Photo by Roman Dial.

Ecological research often involves establishing field plots and then meticulously characterizing the composition and other attributes of the plant community in each field plot. Plot sampling provides valuable information, but the time consuming nature of the approach limits the spatial extent over which measurements can be made. Dial recognized that to better understand recent greening and browning, there is a need for more spatially extensive information on plant community composition than can be provided by field plots alone. He thus has pioneered an alternative approach that involves continuously documenting plant community composition and other attributes while trekking across the landscape. Termed “pixel-walking”, this approach harnesses the multifunctionality of smartphones to record and geolocate visual observations of vegetation composition and density for the overstory, midstory, and understory. While pixel-walking, researchers record a new observation every time they visually detect a change in vegetation composition or density at about a 30 meter spatial scale, corresponding to one pixel from the Landsat satellites. These spatially extensive field observations are thus collected with the explicit goal of being linked to decades of Landsat satellite observations.

Photo by Roman Dial.

Photo by Roman Dial.

Researchers record visual observations of plant community composition and density while “pixel-walking” through the Brooks Range in northern Alaska. Photo by Roman Dial.

During summer 2021, Dial’s research team pixel-walked over 800 miles from east to west through the Brooks Range, collecting data on vegetation composition for about 100,000 Landsat pixels. Over the coming year, Dial’s team will work with Berner, Burns, and Professor Scott Goetz (ABoVE Science Team Lead) at NAU to link these extensive field data with several decades of Landsat satellite observations provided by NASA. This collaboration will help unravel the mysteries of Arctic greening and browning by shedding light on where, how, and why plant communities changed in recent decades. NASA’s Earth-observing satellites provide long-term observations that are crucial for monitoring and understanding ongoing environmental changes in the rapidly-warming Arctic, especially when complemented by field data collected across large regions.

Boreal forest gives way to sparse tundra while heading north into the Brooks Range. Photo by Logan Berner.

The Road to Vandenberg

September 24th, 2021 by David Sibeck/NASA's Goddard Space Flight Center

When asked how you get to Vandenberg Air Force Base, Boston University’s Brian Walsh and his Goddard Space Flight Center (GSFC) co-investigators are likely to reply “Practice, Practice, Practice” and “Teamwork, Teamwork, Teamwork.” They’ve been at this business for quite a while.  

It all started in 2005, when GSFC astrophysicist Scott Porter told GSFC heliophysicist Michael Collier about a soft X-ray foreground signal coming from the vicinity of the Earth that astrophysicists were struggling to remove. The signal was interfering with their efforts to image distant stars and galaxies. Michael’s eyes widened in surprise – he immediately realized that heliophysicists could use this ‘unwanted’ signal. This soft X-ray signal was produced when solar wind ions collided with atoms in the Earth’s outer atmosphere, exchanging electrons. By carefully imaging it, they could paint the outline of the invisible magnetic bubble, or magnetosphere, surrounding Earth that shields us from the oncoming solar wind.

Figure 1.  A conceptual animation showing solar wind interacting with Earth’s magnetic field and causing atmospheric loss at the polar cusps. Credit: NASA’s Goddard Space Flight Center/Conceptual Image Lab/Josh Masters

Colleagues at the University of Kansas ran simulations to calculate the strength of the X-ray signals, while Scott and Michael set out to find the right technology for the task. Working with partners at the University of Leicester in the United Kingdom, they realized that so-called ‘Lobster-eye’ optics could do the trick (see Figure 2). These special cameras could take wide field-of-view pictures of the X-rays. 

Figure 2.  Curved Lobster-eye micropore optics with millions of tiny square pores reflect and focus light (X-ray included) to a point at the center of a cross-hair pattern. Credit: Emil Atz
Figure 3.  The STORM soft X-ray telescope launched on DXL-1. Two out of nine micropore optics were populated for the mission, seen in the center and center/right optics. Credit: Kenneth Simms

Fast forward to the Decembers of 2012 and 2015, and Scott, Michael, and GSFC Post-Doc Brian Walsh are launching prototype ‘Lobster-eye’ telescopes on the DXL-I and DXL-II rocket flights from White Sands, New Mexico. It was near midnight on December 12, 2012. A few hundred feet away, the DXL sounding rocket had just lifted off from White Sands Missile Range carrying, as a secondary payload, the Sheath Transport Observer for the Redistribution of Mass or STORM instrument, the first wide field-of-view soft X-ray imager ever launched into space.  

Michael remembers sitting hunched over a terminal, his index finger hovering nervously over the ‘self-destruct’ button. Should there be any evidence STORM was jeopardizing the success of the main DXL mission, the principal investigator would order Michael to shut it down. Thankfully, that order never came. Despite a bumpy launch and an equally bumpy crash landing, the instruments were recovered, undamaged, from the bone-dry desert plains of New Mexico. They had functioned perfectly throughout their brief flights into the nighttime sky. Michael wrote up the paper and it took pride of place on the cover of the journal.

Figure 4.  The soft X-ray instrument team at the DXL-1 launch in White Sands, New Mexico in December 2012. Credit: NASA

Figure 5.  Results from the first wide field-of-view soft X-ray telescope flown in space made the cover page of Review of Scientific Instruments. 

These successful rocket flights laid the groundwork for Dr. Brian Walsh, now a professor at Boston University, to propose and win funding to fly the very same lobster-eye soft X-ray imager again. This time, it would be the main science instrument on the forthcoming Cusp Plasma Imaging Detector, or CuPID CubeSat.  Brian’s first-year grad student Emil Atz inherited the CuPID design and some hardware from GSFC engineer Lisa Billingsley.  He became responsible for taking the hardware from model to flight, spending days (and nights) in the machine shop and lab making parts, sometimes multiple times because he messed some up and had to remake them.  Emil, now lead engineer, says “I remember wondering whether NASA would ever send something I worked on to space.” One year later he was putting the avionics and instruments into the chassis Lisa had designed and he had modified and built.

Figure 6.   Undergraduate student Thompson Cragwell and PhD student Emil Atz practice assembling the CuPID chassis for the first time. Credit: Thompson Cragwell/Emil Atz

Figure 7.  (From left) Michael, Lisa and Emil prepare the CuPID chassis for its first vibration test, or risk reduction vibe. Results showed the team that chassis performed beyond expectation and could be used for flight. Credit: Brian Walsh

Systems engineering normally conducted by a spacecraft bus vendor was nearly entirely accomplished by the CuPID team. Although the avionics were purchased from a vendor, the design and integration of many elements were conducted by students and GSFC engineers. For example, the BU team built CuPID’s solar panels and the Merrimack team tested the settings for CuPID’s deployable radio antenna. 

Figure 8. BU engineer Aleks Zosuls and Emil lay a sting of solar cells on CuPID’s in house built solar panels.

Figure 9.  Aleks tests CuPID’s solar panel to confirm functionality after a successful build. Credit: Emil Atz

The COVID-19 pandemic caused a lot of problems. Early in the pandemic, Emil and crew drove down from Boston to GSFC to pick up the spacecraft and to keep the work on it going forward. Over the next year, he and colleagues came into the Boston University lab every day, testing the avionics, bus systems, software, and all three instruments. Discovering issues, he would contact the instrument or software teams, ask them what was going on, and conduct more tests and analysis until he figured out the problem. “It was fun – sometimes I felt like a detective,” Emil said. Over the past 4 years he and Professor Walsh have supervised 25 students as they worked on CuPID.

CuPID is now scheduled for launch as a rideshare with Landsat-9 from Vandenberg Air Force Base in California on September 27, 2021. The spacecraft has already been delivered and the team is getting ready to travel. But more about that later…

Landsat 9 to Further NASA’s Food Security Missions

September 23rd, 2021 by Keelin Haynes, Mary Mitkish, and Chris Justice / NASA Harvest

Credit: NASA’s Goddard Space Flight Center / Conceptual Image Lab

“Landsat 9 provides a critical extension of the Landsat data record for monitoring our food supplies and helping to inform and address crucial decisions in how we manage, grow and adapt our food production sustainably under a warming climate, with an increasing population and growing demand for food.” 

– Chris Justice, NASA Harvest Chief Scientist, Program Scientist for NASA’s Land Cover Land Use Change (LCLUC) Program, Land Discipline Leader for the NASA Moderate Imaging Spectroradiometer (MODIS) and the Soumi-NPP VIIRS Science Team, co-chair of the GEOGLAM Initiative.

Credit: NASA

The next generation of Earth observation satellites is scheduled to launch in just a few short days. The ninth sensor in the NASA/USGS Landsat program will continue the mission’s critical work in monitoring how the surface of the Earth has changed in the near-50 years since the first Landsat satellite was launched. Landsat has enabled a number of applications in diverse fields including forest management, fire, and climate. The system has also found extensive use in monitoring global agriculture and food security applications.

Landsat revolutionized what it means to monitor agriculture, analyze crop conditions and estimate crop yields. Provided by advancements in satellite imagery and technology, the ability to remotely monitor crops over large areas and in difficult to access places on a regular basis has lowered on-the-ground labor requirements while simultaneously increasing the amount of analysis that can be performed. Advancements in spatial and temporal resolution, or how “zoomed in” and frequently the imagery is obtained, combined with new computing capabilities have created a variety of novel applications that have completely shifted what is possible in terms of agricultural monitoring and research.

NASA’s Role in Agriculture and Food Security

The first Landsat mission launched in 1972 was designed with agricultural monitoring as a key application for the Earth observations data that would be provided by satellite imagery. These initial Landsat observations were the primary tool for developing early programs for agricultural monitoring which laid the foundation for using satellite data to monitor where and when crops are growing, to observe crop condition as the growing season progresses, and to estimate crop yields and total production from space. As advances in technology and computing capabilities have increased exponentially in the last several decades, NASA has continued to play an important role in monitoring Earth’s agrifood systems.

Recognizing the growing need for a dedicated program focused on food production and access, NASA Harvest was established in 2017 to serve as NASA’s official Agriculture and Food Security program. NASA Harvest combines Earth observation (EO) data, machine learning, and the knowledge of agricultural experts around the world to better inform agricultural decision-making at every level. NASA Harvest partners have made significant use of the Landsat program’s rich data archives in terms of advancing research in mapping crop types, monitoring agricultural conditions, estimating crop yields, and analyzing how management decisions affect productivity and market responses across agrifood systems.

Senior members of the NASA Harvest team such as Dr. Chris JusticeDr. Matt Hansen, and Dr. Eric Vermote have been at the forefront of EO data usage and Landsat applications for several combined decades. While the first Landsat images were simply photographic products, as digital data became available in the 1970s, Dr. Justice started working on data from the first Landsat satellite (ERTS-1) and subsequent missions for land cover classification. Dr. Eric Vermote has been responsible for developing the atmospheric correction procedures for Landsat, which have been adopted by the USGS for operational use, as they moved to distributing Applications Ready Data. 

Reflecting on the program, Chris Justice said “The first Landsat mission was designed with agricultural monitoring as a key application. These early Landsat observations laid the foundation for using satellite data to monitor where crops are growing; crop condition as the growing season progresses; and estimating crop yields and total production from space. Landsat allowed the USDA to develop its Cropland Data Layer program. This approach has become a gold standard among agricultural ministries for annual identification of which crops are growing in their country.

Landsat Joined By Other EO Satellites

Over the years, Landsat capability has been bolstered by other moderate resolution Earth Observation (EO) satellites from the international community, starting with the French SPOT mission in 1986. In 2014, the European Space Agency began launching its Sentinel series of satellites in close collaboration with the Landsat mission, significantly increasing the frequency of observations and adding to the amount of EO data available for research and analysis. These two programs share in the benefits of providing free and openly available medium resolution EO data to the public. As crops change and develop rapidly throughout the growing season, timely and frequent observations are critical and Landsat 9 will play an important role in increasing the frequency of observations. Between two Landsats and two sentinels, available satellite data will provide almost daily observations to observe every field across the globe.

Despite some differences in spectral and spatial resolutions, the two programs complement each other particularly well especially for agricultural applications. A recent study co-funded by NASA Harvest and co-authored by researchers of the University of Maryland’s Global Land Analysis and Discovery (GLAD) group explores how the Landsat and Sentinel satellites compare in crop classification capabilities. This research found that medium-resolution imagery from Landsat 7 and 8 performs on par with the higher spatial resolution offered by the European Space Agency’s Sentinel-1 and Sentinel-2 satellites. Specifically, both sets of satellites are able to classify corn and soybean crops with accuracies above 94% and when their imagery was combined, the team was able to reach accuracy levels of 97%.

Dr. Matt Hansen has also used Landsat data and imagery to create the Global Forest Watch (GFW) product which provides an annual Landsat-based, global tree cover map allowing users to see how the global forest footprint grows and shrinks in different locales every year. Given the relationship between cropland expansion and deforestation, GFW’s annual tree cover data product allows for better analysis of how agricultural production drives forest loss.

Between 1985 and 2016, South America saw significant deforestation and cropland expansion. Credit: Global Land Analysis and Discovery (GLAD)

Decades of Data Enabling Long Term Analysis

The Landsat program is especially unique and useful thanks to its longevity, providing researchers with an unmatched historical data archive. Collecting data for just under fifty years, the satellite mission has enabled longitudinal studies of agricultural change that would otherwise be impossible. One team based at Stanford’s Center on Food Security and the Environment (FSE) which includes NASA Harvest partners Dr. David LobellDr. Jillian Deines, and Dr. Sherrie Wang, have demonstrated this by using Landsat imagery to greatly expand the temporal range of currently available U.S. crop maps. The country-wide crop maps currently produced by the USDA as part of the Cropland Data Layer (CDL), while very accurate, only include information on crops dating back to 2008. The FSE team makes use of the Landsat archive to bolster the existing CDL dataset and map corn and soybean production across the U.S. midwest, going all the way back to 1999.

This graphic from Stanford’s Center on Food Security and the Environment shows annual crop yields across the American Midwest from 1999-2015. Credit: Stanford’s Center on Food Security and the Environment (FSE)

Utilizing even more of the Landsat historical data, this team has also explored how agricultural irrigation has changed in the U.S. midwest over more than three decades. Led by Dr. Jillian Deines, FSE was able to create an annual series of maps showing irrigated cropland within the High Plains Aquifer in the Central United States from 1984 to 2017. This time series of irrigated maps proves vital in understanding how irrigated agriculture is changing in one of the most agriculturally productive regions on the planet, as well as building a strong base for further research into how water conservation can preserve natural aquifers while also increasing farmer profits.

Enabling New Landsat Applications

Landsat 9 provides a critical extension of this 50 year data record for monitoring our food supplies and helping to inform and address crucial decisions in how we manage, grow and adapt our food production sustainably under a warming climate and with an increasing population. Whether it is informing farmer decisions on management practices that support soil health, supporting transparent and stable agricultural commodity markets, providing early warning of impending crop shortfalls, supporting more efficient and effective agricultural insurance schemes, or tracking agricultural expansion, the Landsat program has had an enormous impact on how we understand farming and food security since its inception. With the launch of Landsat 9, new applications can be developed and the legacy of Earth observations for informed decision making continues on.

Visit Landsat Science to learn more about the Landsat program and the upcoming launch.

This Isn’t My First Rodeo

September 2nd, 2021 by Andy Hynous, NASA Balloon Program Office

So, I realize that it’s been awhile, and that in my last blog post (from waaaaaaaaaaaaaay back in January of 2020) I said that we’d be doing a launch from New Zealand but that didn’t quite work out nearly as well as we all hoped…  I wonder what happened…

Anywho, your ever-faithful intrepid engineer is back in the saddle again here in Fort Sumner, New Mexico, for our fall campaign attempt. We did do a spring Fort Sumner campaign earlier in the year, but that is pretty rare for the Balloon Program. Normally, during that time of year, we are attempting to conduct launches from either Wanaka, New Zealand, or the Swedish Space Corporation Esrange facility outside Kiruna, Sweden. Next year in March through June the blogs might be a little more exotic. Why didn’t I put up any blog posts back in the spring?  Well, I was busy … and stuff. We had a lot to do to make both the spring and fall campaigns for this year happen. Now, where was I?

What’s been happening in Fort Sumner, you ask? Good question! We’ve been deployed here to the Land of Enchantment since early August. We currently have nine manifested missions slated for the fall campaign. We’re attempting to launch some science piggyback missions on a couple of Columbia Scientific Balloon Facility test flight missions. We also have a full slate of dedicated science missions we want to launch. AND we have an independent student mission. I’ll be sure to give more info on that one in a later post.

So far, the team has conducted one hand-launch for the NASA Jet Propulsion Laboratory (JPL) science mission WHATSUP. Now, I’ve talked about hand launches in previous blog posts (“More Fun Than a BARREL of Electrons” primarily), but what makes this mission special is that the Principal Investigator, Adrian Tang, is developing a system to go to other planets and measure water content in their atmospheres. That’ll help us understand the composition of gases that make up the “air” on said planets in our solar system. You can see some shots of the WHATSUP mission in the above pictures. The image below is from the launch last week.

Today, we just launched another NASA JPL mission. The JPL-SLS. The balloon, as I’m writing, is at 28,680 feet and climbing. She’s currently climbing at a little less than 1000 feet per minute.  You can check out the current conditions (more likely the final trajectory) here. The JPL-SLS mission is an upper atmosphere science mission for NASA that is looking at and measuring the composition of our own atmosphere. We’ve flown JPL-SLS many times in the past, so they’re able to use their data to measure trends and see how our atmosphere has changed over time.

The opening video is from our launch attempt today (August 28, 2021). That is the JPL-SLS mission being released from the launch spool and the mobile launch vehicle. The last photo for today was taken of the JPL-SLS mission from the flight line.  I hope you enjoy!  I’ll try to do better to keep this updated with more observations from the field. Check back real soon!

From Space to Farm

April 26th, 2021 by Estefania Puricelli (NASA Harvest), Mary Mitkish (NASA Harvest), Inbal Becker-Reshef (NASA Harvest)

How Earth observation technologies are revolutionizing global agri-food systems.

Nowadays, various forms of technology play a fundamental role in our daily routines. From the use of GPS to navigate to different places, to sharing pictures using just our smartphones, to automatic vacuum cleaners, there are endless examples. Even when it comes to the food we eat there have been so many technological advances and an immeasurable amount of research developed, particularly in the past few decades.

But one common technological thread that we can find within all of these different aspects of our lives is Earth Observation Technologies (EOT) and remote sensing. Numerous Earth observing (EO) satellites have been launched into space by NASA and other international space agencies within the last decade, serving to collect (or “remotely sense”) data about our home planet, which helps experts around the world to better understand our ecosystems and environment. We’ll take a look at agricultural production, international food markets, and global food security as an example of the importance of this remotely sensed Earth observation data.

There are several steps and many factors involved from the time a crop is grown on a plot of land to the availability of certain crops and the price volatilities eventually seen in the corresponding food market system. Because of the complicated paths of the agricultural supply chain, it is often easier to understand this relationship if we think about it as a collective “agri-food system.” Over the past decades, agri-food systems have evolved in so many aspects, but so have the EO technologies that make it easier to understand and monitor every step of this complex chain, bringing transparency and efficiency to the overall system. According to the United Nations definition, the food system includes many different factors such as: food-related resources, various food system inputs, production, transport, processing, manufacturing, retailing, and food consumption, all in addition to the overall agri-food system impacts on environment, health, and society. Many of the changes in our food systems are attributed to external and internal forces as well as feedback mechanisms among these forces. 

Let’s start from the beginning—from the farm and from the plot. With the help of satellites and EOT, producers have a better understanding of weather patterns and can plan the optimal time to sow their land. With GPS-based technologies, producers can use precision agriculture to specifically apply only the needed amount of fertilizers, herbicides, and seeds. Once everything is in the ground, farmers can remotely monitor how the crops are developing from anywhere in the world, and they can even estimate the potential yield they can expect at harvest time months in advance of actual harvesting dates. Such tools are extremely important for successful financial planning. While those crops are still developing, we can use EOT to monitor agro-meteorological conditions such as temperature and precipitation, and their impacts on crop conditions—all of which help us understand if today’s conditions are following the average trends seen in previous seasons. If anomalies occur, the EOT data can warn us well in advance of a potentially catastrophic harvest season which enables earlier mitigation actions.

Example of crop charts showing the 2019 growing season in the United States. The season began under mixed conditions due to wet and cooler than average conditions. Heavy rainfall along with spring meltwaters saturated and flooded many fields, leaving farmers unable to conduct sowing until later in the spring. High rainfall values and very high soil moisture values through June combined with lower than average temperatures resulted in sowing being delayed and then a slow start to crop growth. The delayed sowing and slow start to crop development can be seen in the NDVI plot by the month delay in the increase in NDVI values. Near the end of the season, temperatures stayed above normal, helping the maize crop receive additional heat units for development. During harvest, an uptick in rainfall can be observed at the start of November, potentially hampering harvesting operations and increasing grain moisture levels. Overall, due to the wet and cool start to the season, there was a reduction in total sown area along with a reduction in yields compared to the previous year. Image c/o Ritvik Sahajpal.

Meanwhile, as that same crop is growing, many different market actors around the world are trying to estimate how much of that crop will be successfully produced, not only in that specific region but also throughout the whole country and elsewhere around the globe. Consequently, accurate early estimates of crop area and crop yields are fundamental to the efficient and transparent functioning of global agricultural markets. And guess what? Remote sensing technologies play a critical role here too, providing key pieces of information for analyzing and developing estimates at different scales for crop area and yield, making use of NASA satellite data from missions such as MODISLandsat-8, and SMAP, with additional launches on the way (i.e. NISARLandsat-9). 

At a regional level, crop area estimation can also be collaborative. With a simple picture from a smartphone, the average person—meaning those of us who are not agricultural scientists or economists—can now collaborate with crop mapping experts using newly developed artificial intelligence and machine learning applications. For example, novel processes developed by NASA Harvest are leveraging the massification of smart phones, enabling citizen scientists anywhere in the world to assist in gathering pictures of crops, contributing enormously to the accuracy of the models. Image c/o Hannah Kerner.

At a national level, having accurate and timely information helps policy makers to enact more suitable mitigation plans in case they need to take action if there is an unusual shock to the food system (i.e. extreme weather events, food price changes, a global pandemic, etc.), not only for countries whose economies depend on those crops to be exported but also those countries who rely on imports for their food security. EOT can also help to put many farmers literally on the map, and provide policymakers with timely tools and resources to help them. National governments can assess various crop situations using EOT and are currently monitoring the crop conditions with existing National Crop Monitors. Because the agricultural system on a whole is so dynamic, remote sensing technology can also help update estimates of crop production at a national level as the state of the agrifood system changes. 

At a global level, with the help of information provided by satellite data, the early warning community (including the GEOGLAM Crop Monitor for Early Warning and various humanitarian organizations) have a better understanding of the current situation and can utilize early warning information for early action to more efficiently allocate aid where and when needed. Crop production estimates play an important role in price volatility in different markets, both domestically and internationally, which highlights the need for accurate, cost-effective, and frequent agrifood system monitoring. International communities, such as the Agricultural Market Information System (AMIS), have been launched by the G20 in an effort to monitor commodity price volatility. For example, AMIS publishes a crop monitor bulletin in their monthly reports as a way of providing more transparency into agricultural markets. Timely and accurate assessments of crop harvest quantities can have a positive impact in avoiding extreme price volatility. 

But going back to our crop, remote-sensing data and advanced computing capacity improve yield estimates, subsequently improving the financial planning of the producers (i.e. both small- and large-scale farming operations). Remote sensing technologies also improve field-scale nutrient management, not only helping improve sustainability of crop production but also saving on costs for the farmers. Accurate crop area estimates, especially those estimates with a regional approach, help different types of companies—including seed providers, fertilizers, herbicide producers, agriculture services, machinery companies, and many others—to better plan their marketing and distribution strategies. This information creates a more efficient allocation of resources, with benefits also being seen in often under-represented rural areas.

Moving along the food cycle to the post-harvesting stage, if there was a problem with the harvested crop then insurance providers can use remote sensing technologies to assess the situation from anywhere, minimizing cost and emissions of visiting the plots themselves. Remarkably, remote-sensing data can reduce the transaction costs associated with monitoring traditional insurance contracts, reinvigorating rural finance markets. 

But the role of remote sensing technology doesn’t finish when the crop is harvested. Once the crop is out of the ground and for example, sent to the grain elevator, we can track the exact location of the vessels on which those grains are traveling and their destinations. Most recently, we were able to use Planet satellite images to spot the movements of the cargo ship that halted global trade and created a massive bottleneck in the global supply chain. 

Overall, Earth observation technologies are making the interlinkages of the complex and sometimes fragile agrifood systems more transparent, accurate, and efficient, while also helping to reduce transaction cost and shedding light on the information asymmetry challenges. It almost goes without saying that science, innovation, and technology have huge impacts on understanding changes to food systems. Markets, trade, and related infrastructures—increasingly combined with digitization—are today cutting across internal and external drivers of food systems’ change (Von Braun, 2020) and digital technologies will undoubtedly continue to increase efficiency in the design and delivery of agricultural policies (Schroeder, Lampietti, & Elabed, 2021). EOT has the capacity to enable a rapid assessment of different shocks, providing a powerful tool for decision makers across the agricultural, government, and humanitarian spectrums.


Von Braun, J. A. (2020, October 26). Food Systems – Definition, Concept and Application for the UN Food Systems Summit. 

Schroeder, K., Lampietti, J., Elabed, G. (2021, March 16). What’s Cooking : Digital Transformation of the Agrifood System.