Imagery Basics: Terms and Acronyms

Different-resolutions
These photos demonstrate the stark difference between (left) medium and very high resolution.

Field imagery in agriculture has been around for decades. But as the industry stands in “Crop Season 2017,” agriculture still has a ways to go to provide actionable information instead of selling pixels and pictures. Service providers and farmers do not need imagery, they need information — actionable information. They need alerts that tell them there is something that needs to be looked at now — and that there are actions that can be taken to improve profitability. But to get here, the imagery end-user needs to start by understanding what is behind those dots on the page that make up a picture of the farm field.

Understanding Resolution

Resolution is categorized by the pixel size of the remotely sensed imagery. Since the 1972 launch of Landsat by NASA, we know have nearly 1,500 satellites, as well as thousands of airplanes and drones, capturing imagery at different resolutions. Today, we will consider three classes of resolution, as classified by meters (m): Medium Resolution (5 m to 30 m), High Resolution (1 m to 5 m), and Very High Resolution (1 m or better). For agricultural applications, there are a wide range of platforms providing imagery at multiple resolutions and frequency at the global and local scale. The following sections will discuss the sensors and sources of various satellite, aerial, and UAV platforms.

Why does resolution matter? It depends on what is your need. It’s all about aligning the correct information for your problem.

Medium Resolution Imagery (5-30 meters)

NASA’s Landsat is a fantastic sensor that’s been imaging the planet for decades. At 15-meter resolution, it is best used to identify landscape scale change; example uses are zone and drainage plans. Between Landsat 7 and Landsat 8, a new image of the entire planet is taken every eight days. For paid imagery, we have RapidEye at 6.5-meter which is now owned by Planet Labs.

High Resolution Imagery (1-5 meters)

Companies such as Planet Labs and Skybox (now Google) are launching fleets of micro satellites or small sats, with a vision to make imagery cheap, frequent and accessible. They plan to revisit a given place on the globe multiple times a day. While these micro satellites are designed for a short life of 3 years or less, they can take advantage of changes in new sensors. Further, the constellation approach of medium resolution satellites offers a unique revisit for broad crop monitoring area on a daily basis.

Very High Resolution Imagery (< 1 meter) Queue the Airplanes and Drones

This imagery range has been the domain of the airplane imagery provider — and over the last 3 years — drone providers. This imagery is ideally suited to identify and address in-field, in-season agriculture problems.

There are quite a number of airplane and drone imagery providers focused on the agriculture industry. The greatest advantage is that airplanes and drones are able to collect information for specific fields at specific times in the growing season. Part of the challenge is overall inconsistency in the process, which includes the following: no standard type of cameras are used; the quality of pilots or drone operators is variable; and how fast and well the imagery is processed and presented in order to inform the grower or adviser on what to do next.

Another source of very high resolution imagery is the smartphone and tablet. They can take very detailed pictures of plants, bugs, soil and more. Smartphones enabled with personal navigation can be used to cue humans to very specific locations to then capture sub-millimeter color imagery. Smartphone imagery can then be sent to experts and machines for interpretation and diagnosis.

Terminology Alphabet Soup

One of the symptoms of a maturing, competitive industry (and one of its biggest frustrations) is the evolving, swirling, confusing stew of terms and acronyms used to describe differences in technologies and offerings. Imagery terms NIR, VI, UV, TIR, SIR and NDVI (among several more) use to identify and explain the variations of imagery, but do little to help end-users decide what will work in their particular applications.

In a perfect world the industry would evolve to simpler, easier to understand designations and end the TLA (three-letter acronym) madness. What service providers and farmers care about is that when they review the imagery, will it tell them something?

Someday the industry will arrive at that point. In the meantime, these are some of the most common terms in imagery and their meanings and common uses.

  • GSD – Ground Sampling Distance or pixel size of the remotely sensed imagery. Example: 30-meter; 1-meter; 20-centimeters.
  • NDVI – Normalized Difference Vegetation Index is the ratio of the difference between the red and near-infrared bands divided by their sum used to identify and enhance the vegetation contribution in a digital remote sensing analysis.
  • VI – Vegetation Index, is a ratio created by dividing the red by the near-infrared spectral bands used to identify and enhance the vegetation contribution in a digital remote sensing analysis.
  • VRT – Variable-Rate Technology, refers to a system that varies the rate of agricultural inputs such as seed, fertilizer, and crop protection chemicals in response to changing local conditions.
  • TIR – Thermal Infrared is shown in gray tones to illustrate temperature. It measures radiation from the plant and soil surface.
  • NIR – Near infrared (red), green (blue), red (green) is useful in seeing changes in plant health.
  • SIR – Shortwave infrared (red), near infrared (green), and green (blue) used to show flooding or newly burned land.
  • Yield Mapping – refers to the process of collecting geo-referenced data on crop yield and characteristics, such as moisture content, while the crop is being harvested.

Leave a Reply

One comment on “Imagery Basics: Terms and Acronyms

Imagery/Sensing Stories
Imagery/SensingMavrx Acquires Israeli Imagery Provider
May 17, 2018
Taranis, an Israel-based provider of high-resolution agriculture aerial imagery and deep learning, today announced the acquisition of all Mavrx assets, one Read More
Paramount-Reports
Imagery/SensingSatellite Imagery Added to Paramount Reports
May 3, 2018
Paramount Reports, a reporting platform developed by Ag Developer, was built to display data collected on the agX Platform in Read More
Imagery
Imagery/SensingWhere is Imagery in Digital Farming?
April 27, 2018
I was recently asked, “Where is imagery in digital farming?” Imagery, especially from satellites and increasingly from drones, is often Read More
Remote-Soil-Sensing-Mapping
Imagery/SensingRemote Soil Sensing Enhances Precision Farming, Promotes Nutrient Use Efficiency
April 11, 2018
Precision agriculture management requires understanding soil at increasingly finer scales. Conventional soil sampling and laboratory analyses often lack this granularity Read More
Trending Articles
Ernie-Chappell-Screenshot
EventsEFC Systems Sponsorship Demonstrates Commitment to Continuing Education for Retail Dealerships
May 16, 2018
Enterprise software manufacturer EFC Systems, scholarship sponsor of the inaugural PrecisionAg® Professional Accelerator professional development conference this June in Brookings, Read More
Dr Brian Arnall Oklahoma State Paul Schrimpf
Excellence AwardsPrecisionAg Awards Of Excellence Nominations Accepted Through May 18
May 14, 2018
Nominate an outstanding individual for one of four PrecisionAg Awards of Excellence. Recipients will be honored at a special ceremony during the 2018 InfoAg Conference in July. Read More
EventsMeister Media Debuts Growing Innovations
May 10, 2018
As a service provider, you and your grower customers probably can agree on this much: While innovation abounds in agriculture, Read More
UCANR_booth_Food_IT_forum
EventsForum Calling All Innovators of Agriculture Technology
May 2, 2018
The challenges that come with feeding the world continue to grow. Luckily, so do advances in information technology that are Read More
Farm-Storm-Clouds-Photo-Eden-Hills
Data ManagementThe Precipitation Problem in Agriculture
April 17, 2018
Precipitation is arguably the most important agricultural weather parameter, yet it is the most difficult variable to precisely measure. For Read More
SDSU-drone
Business ManagementInside the Key Strategies For Selling Precision Ag Services
April 13, 2018
In its earliest manifestation, the motive for developing precision agriculture service was entirely pure. Agronomists knew that crops were responding Read More
Latest News
Plumblee
Industry NewsNew Clemson Precision Ag Expert Bringing High-Tech Solu…
May 24, 2018
The Clemson Extension Service has hired a new Extension associate to help South Carolina farmers learn how to use technologies Read More
InfoAg ConferenceThe InfoAg Conference Offers Early Bird Registration Di…
May 24, 2018
Since 1995, The InfoAg Conference has been the premier event for discussion and advancement of precision agriculture. The event, organized Read More
CAMP3-team
Data ManagementHow AI, Data and Voice Analysis May Transform Farming —…
May 22, 2018
In 2015, an estimated $800 million worth of crops in Georgia — a number that amounted to about 13.8% of Read More
Farmer-tablet
Data ManagementWhen It Comes to Farm Data, How Good Is ‘Good Enough’?
May 21, 2018
Ron Farrell, a frequent sounding board for my wacky ideas and a source of ongoing encouragement to stay the course Read More
Imagery/SensingMavrx Acquires Israeli Imagery Provider
May 17, 2018
Taranis, an Israel-based provider of high-resolution agriculture aerial imagery and deep learning, today announced the acquisition of all Mavrx assets, one Read More
PrecisionAg Professional Accelerator
EventsWhat’s Stopping You From Maximizing Your Precision Prog…
May 16, 2018
Day 2 of the PrecisionAg® Professional Accelerator will challenge you to evaluate and improve your approach to customer value and Read More
Raven-screenshot
EventsRaven Focused on Retail Education with Top Gun Training…
May 16, 2018
It’s no secret that the demand for precision ag technology is growing. As the world population increases, so does the Read More
Ernie-Chappell-Screenshot
EventsEFC Systems Sponsorship Demonstrates Commitment to Cont…
May 16, 2018
Enterprise software manufacturer EFC Systems, scholarship sponsor of the inaugural PrecisionAg® Professional Accelerator professional development conference this June in Brookings, Read More
Industry NewsPinnacle Joins Crowded E-Commerce Segment With My Pinna…
May 16, 2018
Pinnacle announced today the launch of its new website along with a new interactive grower-customer portal, My Pinnacle. The No.6-ranked Read More
Veris Soil EC
Sensors/IoTUsing Electrical Conductivity (EC) Sensors in Precision…
May 16, 2018
The measurement of soil EC is widely used in agriculture. However, there is still confusion around the meaning of the Read More
Corn Field Sunset
Industry NewsRaven Announces DOT Joint Development Agreement
May 16, 2018
Raven Industries announced today it will be utilizing its precision agriculture technologies to power the autonomous farming solutions of the Read More
Field-Equipment
Sensors/IoTTop 6 Digital Transformation Trends in Agriculture
May 15, 2018
In recent years, technology in agriculture, also known as AgTech has rapidly changed the industry, writes Daniel Newman on Forbes.com. Read More
Data ManagementDigital Farming: Keep It Simple Analytics
May 15, 2018
In previous articles, I tried to lay out some logical components and processes that enable digital farming to get inside Read More
NOAA-Snow-Depth-Analysis-April-15
Data ManagementRebounding Spring for 2018 Planting: Cold April Weather…
May 14, 2018
This month, I am taking a break from discussing weather technology or opining on how to better apply weather and Read More
Dr Brian Arnall Oklahoma State Paul Schrimpf
Excellence AwardsPrecisionAg Awards Of Excellence Nominations Accepted T…
May 14, 2018
Nominate an outstanding individual for one of four PrecisionAg Awards of Excellence. Recipients will be honored at a special ceremony during the 2018 InfoAg Conference in July. Read More
Ag Retailer and Growers with tablet WinField United
Industry NewsCommoditAg Announces Enhanced E-Commerce Platform
May 11, 2018
CommoditAg launches CommoditAg LIVE, described as “an enhanced ecommerce platform providing more benefits to growers, and a superior customer experience”. According Read More
Industry NewsTrimble Adds Crop Health Imagery, Work Orders Features …
May 10, 2018
Trimble announced today that it has added Crop Health Imagery and Work Orders features to its Trimble Ag Software. The Read More
Parkland College Student Training
AmericasBushel Garners $7 Million Private Investment Round
May 10, 2018
Bushel today announced a $7 million private investment round to accelerate its patent-pending digital platform for the grain industry. The Read More