Our HA technology guarantees accuracy of just a few centimeters when collecting control points
For XMobots, a good product is one that generates a high level of profitability for its customers. With the best results in mind, XMobots has developed High Accuracy - HA - technology for its drones.
With HA technology, XMobots products have reached the so-called "next level". The equipment comes with an RTK/PPK system. This guarantees positional accuracy of centimeters, with no control points in drone mapping. The company is the only drone manufacturer in Brazil and one of the few in the world to have this innovation. It therefore produces excellent results with maximum accuracy and reduced mapping costs.
How HA RTK L1/L2 technology works
An RTK/PPK system consists of a base and a rover on board the drone. The base is static and at a known (real or estimated) coordinate. As the base knows its position and is receiving signals from the satellites, it can calculate the signal errors of each satellite. The base then stores the corrections for post-processing (PPK) or sends them to the drone in real time (RTK), such as: each satellite's clock bias error, each satellite's orbit error, ionosphere delay and troposphere delay.
With these corrections, the drone is able to "subtract" the error from each satellite signal. This improves its position solution: the solution to phase carrier ambiguity.
In addition to the above errors, there are others that interfere with the accuracy of GNSS systems. But they cannot be corrected on the drone by the base: multipath, interference and thermal noise from the receiver. It doesn't correct them, but it can identify the faulty signals and eliminate them from the position solution.
As the orbit errors and ionosphere/troposphere delay depend on the location of the GNSS receiver in relation to the satellites, the errors that the base is subject to are different to those that the drone is subject to. However, the shorter the distance between the drone and the base, the more similar the errors are.
Ionospheric and tropospheric delays are a function of frequency. Thus, the higher the frequency, the shorter the delay and the lower the frequency, the longer the delay.
In a nutshell
Drones com RTK/PPK de múltipla frequência “sentem” as frequências L1 (1.575Mhz) e L2 (1.227MHz) dos sinais dos satélites, e a “diferença” entre L1 e L2 é utilizada para estimar os atrasos de ionosfera e troposfera, tornando a solução de posição robusta (confiança acima de 95%) e acurada (<2cm) em linhas de base de até 20km.
Drones com RTK/PPK de frequência simples “sentem” somente a frequência L1 (1.575Mhz) dos sinais dos satélites, sendo assim totalmente suscetível a atrasos de ionosfera e troposfera, tornando a solução de posição frágil (confiança muito abaixo de 95%) e acurada (<2cm) em linhas de base de até 1km.
HA technology therefore provides robust accuracy of 2cm for baselines of up to 20km. With it, it is possible to obtain digital surface and terrain models, contour lines, orthophotos and other imaging products with planimetric accuracy of 1 to 3 times the GSD (Ground Sample Distance) and altimetric accuracy of 2 to 5 times the GSD of the flight.