Drone PPK System

PPK Direct Geopositioning for Drones

What is Loki?

Loki is AirGon’s third generation Global Navigation Satellite System (GNSS), Post-Process Kinematic (PPK) direct geopositioning system for drones. Unlike other direct geopositioning systems on the market today, Loki supports, in “plug and play” fashion, the ubiquitous Phantom 4 Pro and Inspire 2 drones from DJI. Loki turns these low-cost prosumer drones into high accuracy, professional mapping platforms. Of course, Loki also supports high-end drones equipped with digital cameras from Sony, Nikon and others.

 

What is Direct Geopositioning?

Direct Geopositioning is a technique in which high accuracy positioning equipment is flown on a drone to determine camera position estimates for the downstream processing software (PhotoScan, Pix4D, DroneDeploy etc.) that creates point clouds and ortho images. Direct geopositioning dramatically improves the horizontal and vertical accuracy of drone mapping projects, regardless of the project control strategy.

Direct geopositioning has a very rapid return on investment due to the hours of site labor that will be saved by reducing (or eliminating) the ground survey necessary to place control points. Direct geopositioning also can enable drone surveys where they were previously not possible due to the inaccessibility of areas for control placement (mine pits, islands, etc.). In short, everyone who does routine drone mapping will save money and improve results by using a direct geopositioning system. 

Loki turns low-cost prosumer drones like the DJI Phantom 4 Pro and Inspire 2 drones into high accuracy, professional mapping platforms.

- Lewis Graham

GNSS Engine

We have teamed with Septentrio N. V. of Belgium to incorporate their state-of-the-art AsteRx-m2 multifrequency, multi-constellation differential carrier phase GNSS engine into Loki. The AsteRx-m2 is the most advanced small unmanned aerial systems GNSS receiver on the market today. Some of the more salient specifications include:

  • GPS L1, L2, L5 (enabled)
  • GLONASS L1, L2, L3 (enabled)
  • Support for Galileo, BeiDou, IRNSS, QZSS (optional)
  • 448 Hardware Channels
  • IONO+ advanced ionospheric correction
  • APME+ multi-path mitigation

AirGon has implemented the AsteRx-m2 using third generation AirGon computational systems in a Post-Process Kinematic configuration. With a whopping 448 hardware channels and GPS/GLONASS enabled, Loki will track every satellite in the sky!

Surround Technology

While the GNSS Engine is the heart of a direct geopositioning system, a lot of supporting electronics must be designed to realize an integrated, functioning solution. We have updated our second generation AirGon Sensor Package (ASP-2) with the new AsteRx-m2 GNSS engine and completely reworked our system board, camera event detection subsystem (we have a patent pending on this area of technology) and antenna interfaces. We have also made the system self-contained by adding a battery power subsystem. Finally, the entire system has been put on a pretty severe weight diet, enabling it to be easily carried by small drones such as the Phantom 4 Pro.

Performance

The network (“absolute”) accuracy that you can obtain with an aerial mapping system using PPK GNSS depends on a large number of factors such as the accuracy of the reference system, the camera calibration and so forth. That said, results can be quite good for typical site mapping. A recent test (“Wiregrass – 14 July 2017”) of Loki on an Inspire 2 with a calibrated X4S camera resulted in a planimetric ASPRS accuracy class of 4.0 cm and a vertical accuracy class of 6.5 cm – good enough for nearly any high accuracy mapping task!

What’s in the Box

The Loki system contains all of the hardware and software needed to implement direct geopositioning on a DJI Phantom 4Pro/Inspire 2 or a drone carrying a digital camera with a flash hot shoe such as Sony, Nikon, etc. You will need a GNSS base station for reference (not included) The kit includes:

  • The Loki System Controller (including the Septentrio AsteRx-m2 GNSS Engine)
  • Maxtena (M1227HCT-A2-SMA) L1/L2 GPS/GLONASS active GNSS antenna
  • A personality cable (you select DJI or DSLR, depending on your camera)
  • Controller to antenna cable
  • Charging/Data cable
  • Mounting kit for Phantom/Inspire (system is easily mounted to bespoke drones)
  • ASPSuite, Advanced Edition (1 Roaming license)

The ASPSuite (Advanced Edition) includes all software needed to import support files, process the Loki observations in PPK mode and update image headers with the refined position information (an optional CSV file can also be output). We recommend LP360 (not included in the Loki kit) for debiasing point cloud data and performing horizontal/vertical accuracy assessments.

Loki Enabled

Loki outputs a priori X, Y, Z estimates (so-called “Given EO”) for any downstream software. However, some software vendors have specifically optimized their software to take advantage of information created by the AirGon Sensor Package Software Suite. As we roll out Loki, these vendors will be displaying the Loki Enabled logo. Insist on it when you make software buying decisions!!

Frequently Asked Questions

Loki is a Global Navigation Satellite System (GNSS) Post-Process Kinematic (PPK) direct geopositioning hardware & software solution for low cost DJI drones as well as custom drones using digital single lens reflex (DSLR) cameras such as Nikon, Canon, Sony, etc. It is aimed at the high accuracy drone mapping community.

Loki will greatly improve the accuracy of drone mapping projects. It allows a reduction in the number of ground control points needed to achieve a specified horizontal and vertical accuracy level. It can provide a reference to the geodetic network in circumstances where no ground control is possible.

The Loki Controller includes a one year return to factory warranty. This warranty does not cover damage to components caused by a crash or environmental damage (e.g. submersion, exposure to saturating rain, etc.) nor does it cover cables (including the personality cable). All firmware upgrades as well as mandatory board upgrades are covered by the warranty. Upgrades to new hardware versions are not included (although we do generally offer a discounted upgrade path for current system users).

ASPSuite Advanced (the Loki post-processing software) is bundled with the Loki kit and includes 1 year of software updates. Each time you start ASPSuite, it automatically checks for updates. After the one year anniversary, you can purchase an extended service contract for Loki or a software update contract for the software only.

A full Loki support contract (the first year is included with the original Loki purchase) is US $1,200 per year. This covers the Loki Controller (including the internal battery), the antenna and the ASPSuite software. Cables (including the personality cable) are not covered. The warranty and post-warranty support plan do not cover damage due to crashes or environmental damage such as rain, dust or submersion.

The original Loki purchase includes all ASPSuite software updates for the first year. After that time, all updates are included if you purchase the Loki system extended warranty (US $1,200 per year). If you wish to cover the ASPSuite (Advanced Edition) software only, the annual maintenance fee is US $399.

  • DJI Phantom 4 Pro
  • DJI Inspire 2
  • DJI M200/210
  • DJI M600
  • Please contact us for inquiries about custom drones.

Need More Help?

Contact our experienced sales team to find out what solution is best for you.