Understanding Scale In Precision Agriculture

Early in their education, meteorology students learn about the atmospheric scales of motion. Atmospheric scales of motion refer to the relation between the life span of a weather system to its horizontal extent.

At the smallest or “microscale,” turbulent eddies extend over meters to tens of meters in distance and exist for seconds to a few minutes in time. Microscale motion can be seen in a swirl of leaves in autumn. At the largest or “global” scale, polar front and subtropical jet streams encircle the Earth with its meandering long wave patterns that last for weeks or more. Following the seasonal increase and decrease in solar heating, the west to east flow of jet streams migrate north during spring and south in fall. In the mid latitudes, the changing positions of jet streams is evidenced by a change in paths and frequencies of cyclones.

The understanding of atmospheric scales is critical for predicting weather phenomenon. If one wishes to predict microscale eddies, then sensors would have to be arrayed on the order of a meter or less and measurements recorded over seconds. On the other extreme, weather balloons carrying radiosondes are launched twice daily from weather offices many kilometers apart. These instrumented balloons take measurements as they ascend from the surface to the upper atmosphere. Collectively, they can adequately discern the spatial and temporal dimensions of jet streams’ long wave patterns. The distance between instruments and frequency of measurement dictate what weather phenomena can be resolved in an observational network.

Today, the National Weather Service (NWS) networks of weather stations and radar can just barely resolve “mesoscale” weather phenomena, such as thunderstorms and tornadoes which extend over a few kilometers (little more than a mile) and last hours. It is because these networks provide only borderline spatial and temporal resolutions for severe weather, like tornadoes, that the NWS issues “boxes” for areas at risk and watches and warnings for specific time intervals. The public understands that not everyone will be hit by severe weather in a box. But that the risk is high for someone at some point in the box to be hit during the time interval of warning. By using boxes, the NWS is acknowledging the limitations in the spatial and temporal resolutions of its data-collecting systems.

The Importance Of Scale

Like weather, scale is important for precision agriculture. The average crop farm size in the U.S. is about 1,100 acres, or 4.45 square kilometers. If we assume that the average farm is a square, then spatial resolution of its one side would be 2.11 kilometers (1.3 miles). This spatial resolution is at the lower boundary of the atmospheric mesoscale and would be within a NWS box in the case of severe weather. It is also at the very edge of the finest spatial resolution of numerical weather models. The Real-Time Mesoscale Analysis (RTMA) model, developed by the National Centers for En­vironmental Prediction (NCEP), has a spatial resolution of 2.5 kilometers (1.55 miles) and a temporal resolution of one hour. It can provide real-time analyses of weather variables important to agriculture. This analysis model coupled with forecast models at cruder spatial resolutions can provide a weather data feed for programs supporting precision agriculture at the farm scale.

While the best weather analysis models are at the edge of the farm scale, precision agriculture sits at the “field” scale within the microscale of atmospheric motion. Since most decisions in precision agriculture are made at the field scale, biases and inaccuracies will be inherent in the cruder-scale weather analyses and forecasts. The existence of such biases and inaccuracies can be easily appreciated with a simple example. At its farm-scale resolution, the best weather analysis model can only provide a single hourly temperature for an entire crop field. Clearly, a single hourly value cannot accurately represent at the same time the temperature in the shade of a canopy or at the moist surface of a soil. There will be significant differences in temperatures across a field due to the aspect of the land, presence of a canopy, soil texture and moisture content and other physical properties in and around a field. The differences — while hard to measure — will define the microenvironment of plants in a canopy and habitats for pests. These differences are real and represent inaccuracies in weather model output valid at a farm scale.

The Role Of UAVs

Biases and inaccuracies inherent in farm-scale weather analyses and predictions can be corrected by either onsite measurements or other sources of field-level information. Enter the unmanned aerial vehicle (UAV). The UAV or “drone” is a relatively new technology being pursued in precision agriculture. Equipped with the appropriate camera and transmission platform, a UAV can remotely survey a field at a sub-decimeter (5 centimeters) resolution. A UAV can be deployed in short notice and supplement other technologies for collecting field-level data, such as satellite and aerial imagery, in-ground sensors or app-assisted observations. Its field-scale resolution complements the farm-scale weather analysis and forecast models.

The UAV is another tool in the precision agriculture toolbox. Along with weather and agricultural models, remotely-sensed imagery, in situ sensors and manually-collected measurements, it is another source of data for making field-level decisions. Like the sciences and technologies supporting it, precision agriculture tips the scales towards better crop management and more profitable production.

Leave a Reply

Drones Stories
DronesMicaSense Announces Atlas, Pix4D Integration
July 28, 2017
MicaSense Atlas is now integrated with Pix4D desktop software. This exciting partnership is designed to offer MicaSense customers the power Read More
DronesSentera Launches Versatile Quad Sensor for Drones
July 12, 2017
Fully Customizable Filters on Sentera Quad Sensor Allow for Unique Crop Health Detection Capabilities Sentera introduces the latest update to Read More
DronesNavigating a New World: Drone Technology in Agriculture (OPINION)
June 20, 2017
My first exposure to unmanned aerial vehicles (UAVs) was as a master’s student at Kansas State University. I was researching Read More
DronesAg Drone Update: The Hunt for 1,000 (OPINION)
June 10, 2017
Having obtained my FAA Part 107 Commercial Drone Operators license back in September of last year, I’ve spent the past Read More
Trending Articles
Agri-AFC-cotton-baler
Business ManagementBringing a Southern Sensibility to Precision Agriculture
August 7, 2017
Amy Winstead considers herself blessed to have gotten in on the ground floor of precision ag adoption in the Southeast. Read More
Sensors/IoT2017 Yield Monitor Calibration Checklist — Part I
August 4, 2017
With fall harvest a few weeks away for most of the country, ag service providers from every walk of life Read More
Wade-Barnes
Excellence AwardsBuilt By Agronomists: 2017 Award Of Excellence Winner Wade Barnes on the Making of Farmers Edge
August 2, 2017
Farmers Edge President And CEO Wade Barnes reflects on the process of building his company, shortly after receiving the Crop Adviser/Entrepreneur Award during the InfoAg Conference in July. Read More
Data ManagementInfoAg 2017 Recap: Service Providers Take Center Stage
July 28, 2017
As I sit here and ponder just what it was that we all experienced last week, off the top of Read More
Resistant-weeds-in-Brazil
InternationalUsing Precision Agriculture to Control Herbicide-Resistant Weeds in Brazil
July 24, 2017
The occurrence of weeds in agricultural fields of grain and fiber production has caused losses to farmers for a long Read More
Yield Data Image
Data ManagementYield Data: More Than a Pretty Picture
July 13, 2017
It is mid-July, which, for the Australian cotton industry, means that picking is still going on for some growers. A Read More
Latest News
Data ManagementBeck’s Builds Out ‘Freemium’ FMIS Off…
August 17, 2017
Beck’s today announced the release of several new tools available in their precision farming service, FARMserver, which enhances farmers’ ability Read More
Israel-Irrigation-system-featured-image
InternationalIsraeli Precision Ag Companies Lead in Water Use Effici…
August 16, 2017
In the last week, AgriHub, formed by farmers and consultants from Brazil, visited 10 Israeli agribusiness companies, including the Ministry Read More
Gregoire-tractor
ProfessionalsMechanization Key to the Future of Vineyard Management
August 15, 2017
Precision technology moves at different speeds across different segments of agriculture. For example, technologies like curve compensation, precision spraying, and Read More
Area-of-Interest-Web-Soil-Survey-screenshot
Data ManagementSignificant Updates Made to SoilWeb, Web Soil Survey Pr…
August 15, 2017
Agronomic professionals and technicians dealing with precision farming must understand the soils within the field before writing effective prescriptions.  A Read More
Univ.-of-Illlinois-Palmer-in-soybean1
Business ManagementOpinion: How to Leverage Precision Agriculture to Launc…
August 14, 2017
To continue where my last article left off (which you can check out here), a precision ag company that specializes Read More
Industry NewsFarm Dog Inks Non-Funded Cooperative Agreement with USD…
August 14, 2017
Farm Dog, a pest and disease management platform for growers and agronomists, has entered into a Non-Funded Cooperative Agreement (NFCA) Read More
Lisa-Prassack-Photo-Credit-Weekly-Times-Now
InternationalAgtech: What the Umbrella Term Really Means
August 10, 2017
Acclerator, incubator, start-up, connectivity — the buzzwords of the digital age can be clear as, well, mud, writes Alex Sampson Read More
Spray Drift
Data ManagementJanzen: Data to Play Key Role in Sorting Out Dicamba Di…
August 10, 2017
You would have to live under a rock to not have heard about farmers’ issues with dicamba this growing season. Read More
New-Zealand-Precision-Ag-Tour
InternationalNew Zealand Study Tour to Demonstrate Recent Advances i…
August 10, 2017
If you’re interested in an intense, week-long immersion in the use of high-tech products and practices in New Zealand agriculture, Read More
Data ManagementDuPont Acquires Ag Tech Startup Granular for $300 Milli…
August 9, 2017
DuPont announced that it has signed a definitive agreement to acquire San Francisco-based Granular, Inc., a provider of software and Read More
EventsSDSU Prof to lead Profit-Focused Panel at Upcoming Inno…
August 9, 2017
Convening a day prior to this summer’s Farm Progress Show at the I Hotel in Champaign, IL (about an hour’s Read More
AGCO White planter 9800VE
ProfessionalsAGCO Crop Tour 2017 Features Precision Planting Add-Ons
August 8, 2017
Higher yields and greater returns are the ultimate goals for crop producers. To help corn growers better understand the role Read More
Corn
Business ManagementCrop Pro Insurance Closes $8 Million in Series A Fundin…
August 8, 2017
Crop Pro Insurance today announced the close of an $8 million Series A round of financing co-led by top agriculture Read More
Agri-AFC-cotton-baler
Business ManagementBringing a Southern Sensibility to Precision Agricultur…
August 7, 2017
Amy Winstead considers herself blessed to have gotten in on the ground floor of precision ag adoption in the Southeast. Read More
Satshot imagery
Imagery/SensingImagery in Agriculture: Some Sage Advice
August 6, 2017
SatShot President Lanny Faleide has been a fixture on the remote imagery scene for as long as about anyone still Read More
Blue-River-See-Spray-technology
ProfessionalsHow Blue River’s See & Spray Technology Could Chang…
August 5, 2017
The blistering West Texas heat rocketing towards triple digits, the affable cotton grower trudged across his dusty field and approached Read More
Grower Services & Solutions2017 Yield Monitor Calibration Checklist — Part II
August 4, 2017
(EDITOR’S NOTE: This is Part II of Tim Norris’ Yield Monitor Calibration checklist, Part I of which was published in Read More
Sensors/IoT2017 Yield Monitor Calibration Checklist — Part I
August 4, 2017
With fall harvest a few weeks away for most of the country, ag service providers from every walk of life Read More