Srdjan Sobol Applanix Corporation

23F

Using Unmanned Aerial Systems (UAS) with an imaging sensor or a LIDAR scanner to perform high accuracy mapping and surveying in an efficient manner without the need for extensive ground control points requires the computation of position and orientation to a very high degree of accuracy and precision. This is achieved using multi-frequency, multi-constellation Real-time Kinematic (RTK) and/or post-processed carrier phase Differential Global Navigation Satellite Systems (DGNSS) using a GNSS receiver on the UAS and a separate single GNSS reference station or network of stations located on the ground. To achieve centimeter level accuracy, DGNSS techniques require that the distance between the single reference station (i.e., baseline) and the UAS trajectory be less than 20 km. Similarly, when a network of reference stations is employed, the distance should be less than around 70 km to the nearest station. For Visual Line of Sight (VLOS) UAS operations today, the GNSS baseline constraints are easily maintained. However, having to establish a suitable local reference station if a network is not available can add complexity and cost to operations. This cost and complexity will only grow as regulations change and UAS aircraft are allowed to operate Beyond Visual Line of Sight (BVLOS) from the observer.

The geospatial UAS community today is actively seeking new survey operation techniques and solutions that are automated, require minimal interaction with the user and above all are cost effective. Geospatial cloud processing platforms that merely require uploading the raw sensor data and output map products on demand without any interaction from the user are on the rise. On the data collection side, the UAS community is seeking for simplified logistics; no setting up of GNSS reference-stations or survey of control points. This is where Applanix’ direct georeferencing technology and Trimble’s revolutionary Centerpoint RTX Fast positioning service excels.

12:00 UAS-Based Mapping and Surveying Without GNSS Reference Stations and Ground Control Points, Srdjan Sobol