Right on Target: How Trimble and Target Arm got a lock on drone recovery

As drone use surges across North America – from package delivery to critical infrastructure
inspections – the need for pinpoint positioning has never been greater.

The challenge for Target Arm, a U.S. robotics and drone autonomy company, was to leverage its AI-enhanced Ralar® (Robotic Autonomous Launch and Recovery) system to consistently and accurately return the drone to a moving vehicle, at all speeds, autonomously.

While the Ralar system is revolutionary and was designed to launch and recover drones from
moving platforms (cars, trucks, trains and boats), the execution was plagued by fundamental
physics. A simple compass, the standard for heading, was essentially useless. Its data was
skewed by everything from a parked car to rebar buried in the asphalt. This “heading drift”
meant the Ralar system's own orientation was a constant question mark, making it impossible to trust the data a returning drone needs to land with the necessary precision.

The drones themselves faced similar issues. Traditional GNSS was unreliable, in some cases
reporting a drone five meters east one moment, then suddenly shifting the error to the west the next. This erratic “positional drift” meant the drone couldn't reliably track the moving Ralar system, especially when a lack of visual cues made it blind. The entire system – both drone and ground vehicle – was a dynamic reference frame, constantly in motion and where the slightest misstep could cause major problems and failures.

High guidance

Target Arm’s team knew they needed a solution that was not only accurate but also robust, and they found it with Trimble. The solution was two-fold: a combination of high-precision GNSS-inertial technology. On the ground-based Ralar system, they installed the Applanix LVX-125 dual-antenna GNSS-inertial system with Trimble CenterPoint® RTX. Unlike a compass, its dual antennas integrated with inertial navigation provided a rock-solid, real-time heading that was impervious to environmental interference. It delivered a high-rate robust position derived from the fusing of the GNSS and inertial data, allowing the Ralar system's algorithms with their TRACKR sensor fusion engine to predict its position with pinpoint accuracy. The LVX-125's estimated Root Mean Square (RMS) accuracy information also gave the team a real-time check on data quality, ensuring they always knew when the information was reliable or when to transition to a fallback system.

For the drone, Target Arm equipped it with the Trimble PX-1 RTX GNSS-inertial system that
also uses CenterPoint RTX. This device eliminated the erratic shifts and positional
inconsistencies that had previously made accurate returns very unreliable. The PX-1 RTX
provided stable, extremely accurate and consistent position and heading data in the same
global datum as the LVX-125, allowing the drone to navigate back to Ralar and even hold
precise holding patterns near the moving target. It was the missing link – the piece of the puzzle that made on-the-move recovery a reality.

“Before Trimble, erratic heading data and positional drift made drone launch and recovery on
the move unreliable,” said Ryan Bigham, SVP / Lead Engineer Co-Founder at Target Arm.
“Their LVX-125 and PX-1 RTX systems gave us a high update rate, fused GNSS and very
accurate heading information, making Target Arm’s vision of launching and recovering a drone from a moving vehicle much more reliable and accurate.”

Precision without limits

To achieve unparalleled accuracy and efficiency on land and in the air without using base
stations, both the Applanix LVX-125 on the Ralar vehicle and the Trimble PX-1 RTX aboard the
drone leveraged CenterPoint RTX. This global correction service functions through a dedicated global network of GNSS stations that continuously collect raw satellite data to model and calculate atmospheric, orbital and other errors. These error measurements are then broadcast as corrections via L-band satellite or cellular/IP to RTX-enabled receivers, which apply them in real-time using Trimble ProPoint® positioning engine’s GNSS algorithms.

This process simplifies operations, extends coverage and ensures a globally consistent
reference, removing the inconsistencies that often plague local base station setups. For users
such as Target Arm, this solution also provides enhanced immunity to solar disturbances due to its advanced atmospheric models, ASIL-B-certified reliability for safety-critical applications and the elimination of local base stations.

Hitting the mark

With Trimble’s technology, Target Arm unlocked a new level of autonomy. The Ralar system
could now maneuver with confidence, its position and heading tracked with absolute precision. Drones were able to follow, return and be recovered with an elegance that felt almost effortless.

The project’s success showed that Target Arm’s vision wasn’t just futuristic — it was a tangible
reality.