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Proving the Efficiency of PPK Drones for Agricultural Survey

Precision farming technologies are playing an increasing role rapidly changing the way agriculture is conducted. For the efficient management and monitoring of agricultural areas, it is important to acquire accurate information about such areas. This essential data is collected either with the conventional systems (RTK and laser-equipped tractors) or you can do mapping with a drone and this will allow you to achieve much higher efficiency.

UAV for data acquisition

Agricultural mapping is successfully used by Brazilian ArnsTronic founded by mechatronics engineer Antonio Arns. Antonio has more than 10 years of experience in UAV building and precision agriculture. His company designs and manufactures UAVs for data acquisition and processing and provides to its customers a complete crop monitoring plan. To get the precise maps ArnsTronic equips the fleet with the centimeter-accurate Reach RTK while Reach RS is used as a base station. Reach RS is also sometimes used for placing Ground Control Points.

Field survey for agricultural purposes is traditionally conducted with RTK equipped tractors but it may be inefficient for large areas. Mapping with drones saves a lot of time and allows to survey large areas where the conventional approach is unfeasible.

 “With the PPK drone we can survey a much larger area with greater fidelity of the terrain compared to the conventional collection system made with tractor. With tractor we collected 10ha in 1 hour, with the airplane it’s 150ha”—Antonio Arns, Arnstronic CEO.

Let’s take a closer look at the irrigation and drainage project of the rice field. For rice, drainage is as important as good irrigation and the project aimed to provide the best strategy for both.

On the first step, Arnstronic LumiX2 PPK Drone equipped with Reach and Sony camera collected the images for georeferencing. Reach and the camera is connected via hot shoe cable and don’t require flight controller integration. Using ReachView’s Camera Control Tool Reach independently record the position and the time for each photo with sub-microsecond precision.

Arnstronic LumiX2 PPK Drone flying in the sky

LumiX2 PPK drone on a mission


After the flight the collected data is post-processed and the photos are georeferenced with high accuracy for further analysis of irrigation and drainage lines.

Post-processed cm-accurate flight track

Post-processed cm-accurate flight track

Event log containing accurate positional data for each captured photo

Event log containing accurate positional data for each captured photo

Irrigation and Drainage analysis of the processed ortho-map

Irrigation and Drainage analysis of the processed ortho-map


For this study, the accuracy of the processed maps alongside the drainage/irrigation lines has been validated by the farm owner with the laser. The lines then are converted to the autopilot route and used on tractors.

PPK mapping with Reach is used by Arnstronic for processing maps for different types of analysis. The Plant Systematization project outlined below is also based on the positional data acquired with the help of Reach RTK receivers.

The Plant Systematization project

“By using the PPK drone to georeference the maps we can generate planting lines with a precision of 4cm, which increase the operating income by 30%, bringing savings in labor, fuel and maintenance costs.” —Antonio Arns, Arnstronic.

Plant Systematization tools

Plant Systematization tools also reduce the cost of labor, fuel and equipment maintenance


The countries with large production areas like Argentina and Brazil are actively implementing precision agriculture technologies including mapping with PPK drones. It provides processes automation and more accurate field management, which can double and even triple the average yield without adding cultivated area. Arnstronic has already worked on agricultural plans in Argentina, Uruguay, Australia and keeps broadening the range of services. Emlid’s Reach receivers allow Arnstronic to provide reliable services and to keep attractive quality-price ratio on the market.

Visit Arnstronic Website

Start Mapping with Reach and Reach RS

Why using GPS only is not enough?

For most agricultural mapping applications like remote sensing, it is essential to acquire accurate data. Standalone GPS for geo-tagging can’t provide the required precision and may lead to serious deviations between processed maps and reality. For instance maps of big areas may be affected much by cumulative error when processing images collected with standalone GPS. Another example is data sets of 2 identical flights of the same area may provide maps shifted relatively to each other. Such maps obviously will provide inadequate data and as a result incorrect crop plan.

There are two popular and low-cost ways of improving precision when mapping with your drone.

Equip the drone with PPK kit

The first way is to place Reach RTK on a drone and geotag photos using camera hot shoe.  With the data acquired with the Reach Mapping kit, it is possible to process maps with 2cm final accuracy. One of the advantages of this method is that you don’t have to spend hours placing ground control points for large areas. Mapping Kit containing tiny Reach and field-ready Reach RS is available in our online shop!

Reach Mapping Kit

Placing Ground Control Points

The other affordable, yet the accurate method is to use ground control points. It will work great for DJI drones and other UAVs with no access to shutter (the hot shoe is the most popular option) on the camera. For placing GCPs you can use Reach RS receiving NTRIP corrections over the internet.  If the reference station is too far or correction service is too costly you can use 2 Reach RS for centimeter-accurate positioning. By placing enough GCPs in the area you may achieve sub-meter accuracy with just GPS on a drone. The greatest thing here is that you need just 2 Reach RS, tripod, survey pole and any smartphone/tablet with Wi-fi to start getting accurate GCPs yourself.

Reach RS

If you still have questions about RTK or don’t know where to start to check out our documentation and join our community forum!