Inside Unmanned Systems

OCT-NOV 2018

Inside Unmanned Systems provides actionable business intelligence to decision-makers and influencers operating within the global UAS community. Features include analysis of key technologies, policy/regulatory developments and new product design.

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35 October/November 2018  unmanned systems inside corrections to your ground control station. Then they go off to the GNSS receiver via the autopilot and that way you can have your RTK corrections. Loewen also told webinar attendees about satellite-based RTK correction systems that will send the corrections directly to the GNSS receiver and have the least impact on the installation into this system. "Now one interesting variation on RTK systems is the moving base line system and this system you don't know your absolute position you just know your absolute position very accurately," he said. "You do know your absolute position but that high accuracy is relative to some sort of base station that is moving. So here the base station doesn't need to know exactly where it is because it's on the moving vehicle and this is used for a lot of high precision landing and launch systems." This is one of the benefits realized by using dual frequency RTK systems. Loewen's presentation includes a slide explaining the improved accuracy delivered by dual channel RTK. In addition to the better position accuracy, us- ers also get much better velocity accuracy and that velocity accuracy can help with attitude es- timation. The better that attitude information, the more accurately it can f ly the vehicle and the better performance you'll get. So having a better velocity, especially a better velocity estimate, re- sults in a better attitude estimate which, results in better performance. He also covered convergence time and multipath mitigation. SENSOR ARRAY TECHNOLOGY Tilley, a former Air Force officer and a senior en- gineer and executive with more than 30 years ex- perience with remote sensing, mapping and GIS, shared why it's important to get sub millimeter level resolution 3-D models made with Visual Intelligence sensors. His comments focused on the market value of positional accuracy and where accuracy plays in creating value and a lot of the applications of UAS systems. His company focuses in on what they call imaging arrays of cameras, and their proprietary processes and software are designed to precisely calibrate commercially available cameras to be highly accurate, register each pixel in 3-D space and create one measurable image across the field of view of multiple cameras. This translates into faster, more complete image captures that are ac- curate to within two pixels. "We basically take cameras that have level per- formance, put them together with multiple cameras and achieve even better performance," he said. "The cameras can be configured in multiple ways, color, infrared, high resolution and wide field, which is one of the values of the array because we can kind BY THE NUMBERS » PARTICIPANTS´ VIE S The most important factors in determining which positioning solution to utilize are: What qualities of a position can be improved by using a dual or triple band (L1/L2/L5) RTK system vs. an L1-only RTK system? (select two) Acquisition time 52% Multipath 81% Accuracy 85% Jamming 14% Better tracking 44% Spoofing 4% Effectiveness of error resolution 56% Atmospheric interference 40% Form factor—size, weight and power 48% Post-processing software 23% Ease of integration 33% Repeatability and stability 61% Cost 51% What are the most common issues that impact your position fix? (select your top two) L1 RTK is good enough 4% Other factors: signal obstruction, radio interference 63%

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