What satellites are telling us about our land
By Jessica Goodfellow
Through combining satellite imagery and field data, a wealth of information and possibilities emerge. Satellites orbiting the Earth can help assess plant health, soil moisture levels, and even help predict crop yields.
Leander Campbell, a Remote Sensing Analyst with Agriculture and Agri-Food Canada, is part of a five-person team of geomatics specialists that produces a yearly Crop Inventory Map, among other products. The map, which shows what crops are grown in virtually every field across Canada, has consistently been a top download on the Government of Canada Open Data website and has been used by governments, NGOs, and conservation groups alike.
“To make policies and programs more effective, you need to have good quality information to base those on,” Campbell explains. “When you do these maps year after year, you can start to look at agriculture temporally so you can see how it’s changing or evolving. You begin to see trends, and can analyze the where and whys.”
We sat down with Campbell to ask him more about his work and this exciting, innovative branch of agriculture.
Q: What does the work of a ‘satellite image tracker’ involve? Can you take us through the process?
A: I do a lot of imagery work, so I plan the satellite acquisitions. The satellite observations are confirmed using provincial crop insurance data, but in some provinces where crop insurance information isn’t available, we have to travel ourselves to get the information. We have a GPS enabled tablet and so we drive by and we mark down what’s growing in each field. It’s an interesting and long process! We integrate the data and are constantly doing quality control checks of the various stages in the process. For me, it’s the perfect blend – doing what I love, in an area I’m interested in.
Q: How have you seen the technology evolve?
A: With the rise of big data, there has been a confluence of better technology. There are more satellites going up. The more satellites that go up, the more competition there is which reduces the price of satellite imagery, making it more accessible. Computer speed and processing times are much quicker now, versus 5 or 10 years ago. With more satellites, we now have even more data to use. Hopefully, more powerful computers will come along that will make it easier to process all this data. It’s constantly evolving. It’s been fascinating so far, and the next few years will be really interesting.
Q: You mention that your team also produces a weekly map that assesses plant health across Canada. How exactly does satellite imagery read plant health?
A: The satellite we use for this is an optical satellite, which is what you’d mostly be familiar with if you’ve ever looked at Google Earth. They collect visible light - red, blue, greens – but they also have a sensor that collects infrared information. That’s important to agriculture because crops reflect infrared information. A plant reflects even more infrared light when the chlorophyll is flowing strong. When the plant is affected by drought, disease or pests, it’s not producing as much chlorophyll, therefore it’s not reflecting as much of the infrared.
Q: There are also maps produced that display soil moisture. How does that work?
A: Another group that works with us is the National Agro-Climate Information Service, and they create a weekly map of the moisture content of the soil. They use microwave based imagery, so they’re looking beyond infrared. You can calculate what the moisture content is of the soil by assessing how much microwave energy passes through it.
Q: What role does or could this data play in analyzing the effects evolving weather patterns?
A: One of the things that we map every year is a class called ‘Too Wet to Seed’. For example, in 2011 when they had the Red River Flooding out in Manitoba, we were able to tell which fields were too wet to produce crop that year due to the moisture content of the soil. It gives you a picture of how many acres were affected. When you can actually see it, it starts to hit home. Our maps, coupled with other data streams, can start to show which areas that will be affected by severe weather events more often. And even now, we’re considering mapping in the Yukon because we’d like to get on board with that sooner than later. Warmer weather and better plant genomics are expanding production. If the climate continues to evolve and change, then you might see farmers step away from certain crops and into other crops, so that will show in our maps as well.
Q: You spend much of your summers driving across Canada, collecting data. What did you find most interesting about Canadian agriculture?
A: Overall, just the diversity of it. It wasn’t something I realized growing up in Ontario where corn, soy, wheat were the three big commodities. It’s just amazing how in you can see so much diversity in just a little area. North shore Lake Erie, for example, is just wild with various fruits and vegetables, and you have tobacco and ginseng growing there as well.
Photos courtesy of Leander Campbell
Q: What about this technology sets Canada apart?
A: There’s a joint project between Statistics Canada and AAFC. The idea is that you can use the satellite information, meteorological data, and historical data of crop yields and weather patterns to estimate crop yields for that particular year. We’re the first nation to operationalize the data in this way.
Q: What advances are in store for the team/ what areas are you looking to develop?
A: Everything! We’re constantly trying to evolve – to make it a better product, a more accurate product, to get our maps out quicker because it’s a lot of data that we’re processing. Another thing we’re trying to do is to create a better end product for people. If you’re not familiar with the system, it is a little cumbersome to use. Always listening to the public seeing where we’re doing things right, and where we can improve.
Jessica has worked in communications with international and domestic agricultural organizations over the past 11 years, including the Canadian Federation Agriculture and the International Federation of Agricultural Producers. Currently, Jessica is completing her studies in nutrition and has launched LEAP PROJECTS to help bring creative communication services to non-profit organizations.