Drones have become a disruptive technology with payload and customized drones. The use of NDVI cameras to assess the health of crops is one example of this.
Crop inspection can be done more precisely and with less manual effort with drone-mounted NDVI cameras. What is NDVI, and how does it help farmers manage their crops more precisely?
This post will look into NDVI cameras and drones compatible with NDVI in-depth, including how they function and which kinds are now available.
What Is NDVI?
NDVI stands for Normalized Difference Vegetation Index and is a graphical indicator used by farmers to examine remote sensing information and determine whether or not the area has living green vegetation. NDVI pictures aid farmers in fertilizer application, yield estimation, and weed identification.
The NDVI is calculated using the following formula:
The NDVI value for any subject will be in the range of -1.0 to +1.0 by design. The advantage of utilizing a normalized index instead of a simple ratio of near-infrared light to visible light is that values are limited to a relatively narrow range.
This eliminates the issue of a ratio’s range of values ranging from zero to infinity, which may make numbers exceedingly complex.
According to its mathematical definition, densely vegetated regions should have higher positive values ranging from 0.3 to 0.8. Clouds and snowfields, for example, reflect more visible light and have negative NDVI values.
Because bare soil surfaces reflect a tiny amount of near-infrared light, NDVI readings in the range of 0.1 to 0.2 are somewhat positive. Because water has a low reflectance of both visible and near-infrared light, NDVI values around zero, either very partly negative or positive, can be predicted.
What Are the Best Drones That Compatible with NDVI Cameras?
DJI Phantom 4 Pro
When you think about drones, the classic design of the DJI Phantom series might be the first thing that springs to mind.
DJI is well aware of this, and its Phantom drones are among the best high-end consumer quadcopters on the market. The Phantom 4 Pro and Phantom 4 Pro+ were released alongside the Inspire 2 in the fall of 2016, continuing the pattern.
The only difference between the Phantom 4 Pro and the Phantom 4 Pro+ is the Pro+’s remote, which has a 5.5-inch built-in display. Although the display is attractive and runs Android, that is the sole difference between the two devices.
The Plus variant has a built-in display on the remote control, but the machine is otherwise identical.
The Phantom line’s standard color is white with grey accents. A new Obsidian version looks great but is the same drone on the inside.
Almost every side of this drone has obstacle avoidance sensors. The drone will avoid a collision in all directions except upward while operational. The forward and downward sensors can also assist in maneuvering the drone, such as skirting around obstacles and landings with accuracy.
The Inspire 2 has a few unique features that set it apart from the competition, but it just has more power under the hood. DJI calls it the Inspire 2 because it has two (or more) of everything, in our opinion.
The twin battery configuration, which provides the Inspire 2 with several major advantages, is arguably the most important feature.
It not only extends the flying length of the bird, but it also protects it against battery failures and, more crucially, supplies enough power for auxiliary equipment like cameras, stabilizers, sensors, and processors.
We like to think that DJI calls it the Inspire 2 because it has two (or more) of everything.
Not only does this drone have a detachable and readily upgradeable Zenmuse camera (ours came with the X5S), but it also has a forward-facing FPV camera that allows the pilot to keep an eye on what’s ahead of the drone while watching/controlling the Zenmuse camera.
Dual inertial motion sensors, dual barometers, and specialized CPUs for different subsystems — including the newly added obstacle avoidance sensors — are also included.
It’s even possible to fly it with two controls. These new features work together to make the Inspire 2 significantly more dependable, stable, and safe to fly than any prior model.
DJI Mavic Drones
The DJI Mavic Pro Platinum is the best tiny drone compatible with the NDVI camera that you can buy. Its tiny folding design fits neatly in a camera or messenger bag, and it comes with a dedicated remote.
It has excellent flying performance, 4K video, and built-in safety measures such as autonomous return-to-home and forward obstacle avoidance.
Although DJI has other higher-end alternatives, like the Phantom 4 Pro and Inspire 2, it’s a terrific choice for most aerial videographers and YouTubers, as well as our Editors’ Choice.
Longer flying periods and quieter operations are two improvements over Pro Platinum’s predecessor. Both are the product of engine and propeller design improvements.
It’s quieter—the difference can be heard in the footage above. Both drones were captured with a Nikon D850 with manually adjusted audio levels and a Rode VideoMic from the same location.
What Are the Best NDVI Cameras for Drones Available Today?
Drones are still in their infancy when it comes to agricultural surveys. NDVI cameras have recently been made compatible with drone technology, even though the technology has been around for a long time.
People who want to do NDVI surveys with drones now have two options: upgrade their existing DJI drones with extra NDVI sensors or purchase a fully packaged NDVI camera drone kit.
Cameras compatible with DJI drones have been developed by a lot of companies.
#1. Sentera NDVI Upgrade
The Sentera NDVI upgrade for DJI drones is the most cost-effective yet still high-quality solution to include an NDVI camera on your drone.
Sentera is a well-known precision agricultural company that has a device that can be used to upgrade your DJI Phantom 4 Pro, DJI Inspire, or DJI Mavic drone.
You can choose either a High Precision NDVI or NDRE 1.2MP NIR global shutter Single Sensor.
Sentera’s 1.2 MP NDVI Single Sensor is the world’s smallest and lightest NDVI sensor. It works with all Inspire and Mavic drones and the Phantom 4 Pro V2.0.
Both options interface directly into DJI’s software, allowing for geo-tagging and time-stamped photographs for speedy field scouting and problem diagnosis.
A one-year subscription to the FieldAgent software is included with the purchase of the Sentera NDVI camera. This app may be used to see and alter data on all of your mobile devices and a PC to create endless ortho-mosaics.
The Mavic upgrade from Sentera costs around $2000 (not including the price of the Mavic drone). We recommend combining it with the DJI Mavic 2, the most recent model.
One of the best things about the Sentera NDVI camera is that it doesn’t interfere with your DJI drone’s standard camera or gimbal. This means you may continue to operate your DJI drone normally, which is wonderful since the Sentera NDVI camera is semi-permanently affixed.
While the Mavic upgrade is the default/only option, it’s a fantastic choice! The DJI Mavic 2 is wind-resistant, with 29–38 kph speeds. It also has a longer flying period of 31 minutes and a more reliable video transmission system.
You’ll love the drone’s upgraded OcuSync 2.0 video transmission technology, which includes higher interference resistance and auto-switching capabilities that support both the 2.4 GHz and 5.8 GHz frequency bands and supports both 2.4 GHz and 5.8 GHz frequency bands.
You’ll still get 1080p video transmission streams (on the drone’s built-in camera) even if you’re up to 8 kilometers away.
If you’re flying near trees or other impediments, an upgraded Advanced Pilot Assistance System (APAS) allows the plane to evaluate its surroundings and autonomously fly past them without stopping.
#2. MAPIR’s Survey 3W NDVI Mapping Camera
MAPIR’s Survey 3W NDVI Mapping Camera is another way to offer an NDVI upgrade to an existing DJI drone. This camera is roughly the same size as a GoPro Hero and can be mounted on various popular drones using one of their many attachment choices.
Mounts for the Survey 3 cameras are now available for the Phantom, Inspire 1, and Mavic Pro.
The Survey 3 cameras may capture near-IR, red, and green bands. Although the actual capture speed will be restricted by the write speed of the microSD card used, it features one of the quickest interval timers at 1.5 seconds.
A feature of the Survey 3 cameras that we enjoy is an external GPS receiver that automatically geotags each image captured by the camera.
#3. Alternative: Buy an Agricultural Surveying Drone
Another alternative is to purchase a drone made specifically for agricultural surveying.
Because of the superb Parrot Sequioa Plus multispectral sensor, Parrot has become a premium name in this industry.
This sensor combines a 16MP RGB camera, a 1.2 MP single-band camera, a GPS receiver, an IMU, and a magnetometer into one integrated module.
In other words, it has all of the sensors you’ll ever need for a crop health assessment in a very light and small design.
The Parrot Sequioa Plus has four bands instead of the three that conventional NDVI cameras have: green, red, red-edge, and near-infrared.
A separate sunshine sensor captures the level of sunlight, allowing for extra data refinement and processing choices. The Parrot Sequioa Plus was created with the Pix4D image processing software.
Parrot didn’t stop with an excellent multispectral sensor: their two drone models, the Parrot Sequioa + the Parrot Bluegrass, provide end-to-end crop health survey solutions.
The Parrot Sequioa + the Parrot Bluegrass is a typical quadcopter that provides surveyors with the typical ruggedness and ease-of-use of quadcopter drones.
The Parrot Bluegrass Field smartphone app that comes with the drone allows you to produce NDVI maps in real-time while the drone is still flying, allowing you to change survey parameters without having to start over.
The data acquired by the Bluegrass may be analyzed using the Pix4Dfields program for a complete examination.
Pix4Dfields’ built-in algorithms simplify constructing index maps and prescription maps for trouble regions.
Pix4Dfields data can also be connected to a farm management information system (FMIS) platform for seamless integration with actual farm management in the field.
For highly experienced drone pilots who wish to cover large regions fast, Parrot also offers the Parrot Disco-Pro Agf.
Instead of a quadcopter, the Disco-Pro Ag is a fixed-wing drone that can cover up to 60 hectares in a single cycle because of its long battery life.
The drone has live video streaming capabilities via the FreeFlight Pro software but no real-time NDVI mapping capabilities.
The AIRINOV First+ program, a cloud-based agricultural mapping platform that gives thorough reports and actionable insights based on your created NDVI map, is one of the Disco-Pro Ag’s advantages.
How to Install an NDVI Camera for Your Drone?
This is how it works: you purchase a DJI drone (Inspire, Mavin, or Phantom 4 Pro). After that, you’ll need to ship your drone to Sentera or a Sentera-authorized dealer, who will return it to you as a precision ag tool with your new NDVI camera installed (you can also buy one already upgraded).
One important note that may be a deal-breaker: adding the NDVI or NDRE sensor to your Mavic 2 drone (or any DJI drone) voids the DJI manufacturer’s warranty.
How Does an NDVI Camera Work?
An NDVI camera differs from a standard camera in that it has sensors that can collect non-visible light, notably light in the infrared spectrum.
Thus, an NDVI camera effectively combines an infrared and a standard RGB camera.
Reflected light acquired in the infrared and visible light ranges is stored separately in distinct pictures, and their values can be merged in a variety of ways to create composite NDVI images.
There are additional cameras that use “synthetic NDVI.” These cameras, like any other camera, have RGB sensors, but they’re designed with an algorithm that mimics near-IR light and calculates a “best guess” NDVI value.
Although synthetic NDVI cameras are more cost-effective, they are not suggested for commercial usage. Because NDVI is already a restricted technology, a “best guess” NDVI is likely to exaggerate the technology’s flaws.
What Are the Benefits of Drone Mapping Using NDVI?
Before being installed on drones, NDVI cameras were largely employed to analyze worldwide vegetation conditions by orbiting LANDSAT satellites.
This is only suitable for large-scale research in locations like rainforests and vast swaths of cropland. Scientists and farmers may undertake smaller-scale research on crop health and vegetation changes using drone-mounted NDVI cameras.
Flying at lower altitudes also gives significantly greater resolution, allowing for capturing minute features not seen on satellite pictures.
Manually surveying otherwise inaccessible woods is time-consuming and dangerous. NDVI mapping using a drone provides a low-effort and safer option.
Farmers also save a lot of time and work when monitoring crop conditions by simply flying a drone over their whole property on an automatic course.
Drone mapping using NDVI can cut many weeks of labor down to a few hours. Because airborne drone surveys are simple to automate, they are easy to repeat and reduce the impacts of human error.
Despite its versatility, understanding and utilizing NDVI in various scenarios necessitates understanding its limits. Several external factors may impact NDVI values in a given research region, and the impact of these factors cannot be defined or controlled using standard NDVI measurements.
The cloud cover, which may create enormous shadows on places with otherwise dense vegetation, is the most typical difficulty faced while collecting NDVI data.
Other atmospheric factors, such as high humidity and the presence of particles, have a negative impact on light transmission rates.
When NDVI technology is used to examine bare soil, it also creates an issue. This is because soil changes color when it absorbs rainfall, providing the mistaken appearance that changes were caused by plants rather than precipitation.
Because NDVI is based only on reflect light, it needs to deal with the problem of anisotropy. This is the difference in angles of reflected light from surfaces of various orientations.
This means that the NDVI of every survey region will vary naturally owing to changes in angular illumination and the observation of various objects at different times.
The most frequent way for overcoming these restrictions is to create composite NDVI maps from data collected over multiple days or weeks.
However, because this corrective step does not directly address the constraints indicated above, there is no guarantee of the degree of accuracy and representation of the created models.
The invention of the improved vegetation index gave a significantly more elegant and long-term answer.