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
DronesDrone Analyst: The War is Not Over
January 29, 2018
Via DroneLife.com: I’ve been researching and writing about agriculture drone solutions since early 2012, writes SkyLogic Research CEO & Founder Read More
DronesVenture Capital News: PrecisionHawk Secures $75 Million Funding Round
January 24, 2018
According to a recent press release, PrecisionHawk, Inc. announced it has raised a $75 million round of funding from a Read More
AmericasPrecision Farming Companies to Watch in 2018 (OPINION)
January 17, 2018
My friends, as many of you told me repeatedly throughout the last 12 months, 2017 was an interesting year in Read More
DronesCrop Protection Application by Drone: A Q&A with Kray Technologies CEO Dmytro Surdu
January 15, 2018
January is a busy month for agricultural companies. It’s a month that strong sales can set the mood for the Read More
Trending Articles
AsiaCloud-based Irrigation Could Double India’s Crop Yield and Halve Water Use
February 12, 2018
A cloud-based, micro-irrigation system tested on a farm in India has cut water use by up to 80%  and doubled Read More
Tools & Smart EquipmentAutonomous Tractors Could Work in Wetter Conditions than Traditional Tractors
February 8, 2018
March 20th is the first day of spring, making spring much closer than even I expected. On the farm I Read More
AmericasPrecision Farming Companies to Watch in 2018 (OPINION)
January 17, 2018
My friends, as many of you told me repeatedly throughout the last 12 months, 2017 was an interesting year in Read More
Data ManagementPrecision Ag Hardware and Software: A Little Off-Season Maintenance Goes A Long Way
January 11, 2018
All service technicians have heard this line. Most often when spring makes its anticipated return to our lives. It is Read More
Service ProvidersAnez Consulting: Focus On Fertility
January 9, 2018
Central Minnesota features variability aplenty when it comes to soil characteristics and topography, from flat, black expanses rich in organic Read More
Americas5 Best Ag Tech Shows in Brazil
January 8, 2018
Brazil continues to demonstrate its potential in agriculture. Several international companies are investing in our country because we have a Read More
Latest News
Industry NewsUnderstory Patents Solid State Weather Sensor
February 16, 2018
Understory today announced that it received a patent for its mechanical strain-based weather sensor, a key component in its weather Read More
Retailer Grower
Business ManagementAgriculture and Technology: Industry Progress Lies in C…
February 16, 2018
Water is essential for agriculture. While this may seem obvious, nowhere is it more apparent than the Sonoran Desert of Read More
Industry NewsAgtegra Cooperative Pledges $500,000 to SDSU Precision …
February 15, 2018
Agtegra Cooperative, Aberdeen, SD, today in Pierre announced a $500,000 donation to South Dakota State University for the Precision Agriculture Read More
Ag Retailer and Grower WinField United
Business ManagementThe Importance of Teamwork for Successful Precision Ag …
February 15, 2018
Interdependency is defined as the quality or condition of being mutually reliant on each other. I’m not a huge sports Read More
Data ManagementAgriculture Impacts Weather: The Case for Connected Eco…
February 15, 2018
It’s fascinating to see how modern technology has helped us increase our agricultural productivity in areas not otherwise suited for Read More
Adapt-N VRT
Decision Support SoftwareDTN Partners with Adapt-N to Provide Weather and Nitrog…
February 14, 2018
DTN has announced a partnership today at the National Farm Machinery Show with Agronomic Technology Corp (ATC), a Yara International Read More
Corn close up
Imagery/SensingSyngenta Acquires Satellite Imagery Provider FarmShots
February 14, 2018
Syngenta has acquired FarmShots, Inc., a North Carolina-based innovator of high-resolution satellite imagery that detects plant health by analyzing absorbed Read More
Tools & Smart EquipmentMachine Learning: The Secret Sauce of Precision Agricul…
February 13, 2018
With the development of agricultural technologies, crop and plant diseases have been advancing as well, causing degradation of both quality Read More
Farmers Edge Truck
Africa/Middle EastFarmers Edge Aligns with PartnerRE to Streamline Crop I…
February 13, 2018
Today Winnipeg-based FMIS giant Farmers Edge announced a partnership around crop insurance with Zurich-based PartnerRE. Although a bit short on Read More
Robotics Specialty Crops
AmericasHortau, Agrian Announce Strategic Partnership
February 12, 2018
Hortau today announced a strategic partnership with Agrian Inc. to deliver an expansive precision irrigation service for commercial agriculture. “With Read More
AsiaCloud-based Irrigation Could Double India’s Crop Yield …
February 12, 2018
A cloud-based, micro-irrigation system tested on a farm in India has cut water use by up to 80%  and doubled Read More
Forbes Mixing Bowl NYC
EventsInnovative Forum Geared to Let Food, Farming, and Tech …
February 9, 2018
Industry innovators in agriculture, food, and information technology are set to mix it up again at this year’s Forbes Mixing Read More
Tools & Smart EquipmentAutonomous Tractors Could Work in Wetter Conditions tha…
February 8, 2018
March 20th is the first day of spring, making spring much closer than even I expected. On the farm I Read More
corn weather
Industry NewsSciFi in Ag: Stanford Cooling Project Could Drive Energ…
February 7, 2018
(Article Notes: This monthly column takes some crazy sounding ideas and applies them to the field of Ag Tech. The Read More
Industry NewsAgGateway Debuts ADAPT ISO Plugin Version 2.0
February 6, 2018
AgGateway’s ADAPT Framework, which is designed to make it easy for various hardware and software systems that growers use in Read More
Systems ManagementThere’s No Easy Button For Value in Variable-Rate Nutri…
February 6, 2018
Roger Dumond has weathered the ups and downs of precision agriculture programs as much as anybody who’s been riding that Read More
Business ManagementFeel Something is Missing in Precision Agriculture? Ans…
February 5, 2018
I’ve seen a lot of ideas and met a lot of people in the agtech world. There have been great Read More
HomeSST Software to be Acquired by Proagrica
February 5, 2018
UPDATED 2.5.18, 2:10 PM Proagrica has signed an agreement to acquire 100% of SST Software, including Raven’s ownership stake. Based Read More