English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Efficient mapping from unmanned aerial platforms cannot rely on aerial triangulation using known ground control points. The costand time of setting ground control, added to the need for increased overlap between flight lines, severely limits the ability of smallVTOL platforms, in particular, to handle mapping-grade missions of all but the very smallest survey areas. Applanix has brought itsexperience in manned photogrammetry applications to this challenge, setting out the requirements for increasing the efficiency ofmapping operations from small UAVs, using survey-grade GNSS-Inertial technology to accomplish direct georeferencing of theplatform and/or the imaging payload. The Direct Mapping Solution for Unmanned Aerial Vehicles (DMS-UAV) is a complete andready-to-integrate OEM solution for Direct Georeferencing (DG) on unmanned aerial platforms. Designed as a solution for systemsintegrators to create mapping payloads for UAVs of all types and sizes, the DMS produces directly georeferenced products for anyimaging payload (visual, LiDAR, infrared, multispectral imaging, even video). Additionally, DMS addresses the airframe’srequirements for high-accuracy position and orientation for such tasks as precision RTK landing and Precision Orientation for AirData Systems (ADS), Guidance and Control.  This paper presents results using a DMS comprised of an Applanix APX-15 UAV with a Sony a7R camera to produce highlyaccurate orthorectified imagery without Ground Control Points on a Microdrones md4-1000 platform conducted by Applanix andAvyon. APX-15 UAV is a single-board, small-form-factor GNSS-Inertial system designed for use on small, lightweight platforms.The Sony a7R is a prosumer digital RGB camera sensor, with a 36MP, 4.9-micron CCD producing images at 7360 columns by 4912rows. It was configured with a 50mm AF-S Nikkor f/1.8 lens and subsequently with a 35mm Zeiss Sonnar T* FE F2.8 lens. Both thecamera/lens combinations and the APX-15 were mounted to a Microdrones md4-1000 quad-rotor VTOL UAV. The Sony A7R andeach lens combination were focused and calibrated terrestrially using the Applanix camera calibration facility, and then integratedwith the APX-15 GNSS-Inertial system using a custom mount specifically designed for UAV applications. The mount is constructedin such a way as to maintain the stability of both the interior orientation and IMU boresight calibration over shock and vibration,thus turning the Sony A7R into a metric imaging solution.  In July and August 2015, Applanix and Avyon carried out a series of test flights of this system. The goal of these test flights was toassess the performance of DMS APX-15 direct georeferencing system under various scenarios. Furthermore, an examination of howDMS APX-15 can be used to produce accurate map products without the use of ground control points and with reduced sidelap wasalso carried out. Reducing the side lap for survey missions performed by small UAVs can significantly increase the mappingproductivity of these platforms.  The area mapped during the first flight campaign was a 250m x 300m block and a 775m long railway corridor in a rural setting inOntario, Canada. The second area mapped was a 450m long corridor over a dam known as Fryer Dam (over Richelieu River inQuebec, Canada). Several ground control points were distributed within both test areas.  The flight over the block area included 8 North-South lines and 1 cross strip flown at 80m AGL, resulting in a ~1cm GSD. Theflight over the railway corridor included 2 North-South lines also flown at 80m AGL. Similarly, the flight over the dam corridorincluded 2 North-South lines flown at 50m AGL. The focus of this paper was to analyse the results obtained from the two corridors.  Test results from both areas were processed using Direct Georeferencing techniques, and then compared for accuracy against theknown positions of ground control points in each test area. The GNSS-Inertial data collected by the APX-15 was post-processed inSingle Base mode, using a base station located in the project area via POSPac UAV. For the block and railway corridor, the basestation’s position was precisely determined by processing a 12-hour session using the CSRS-PPP Post Processing service. Similarly,for the flight over Fryer Dam, the base-station’s position was also precisely determined by processing a 4-hour session using theCSRS-PPP Post Processing service. POSPac UAV’s camera calibration and quality control (CalQC) module was used to refine thecamera interior orientation parameters using an Integrated Sensor Orientation (ISO) approach. POSPac UAV was also used togenerate the Exterior Orientation parameters for images collected during the test flight.  The Inpho photogrammetric software package was used to develop the final map products for both corridors under various scenarios.The imagery was first imported into an Inpho project, with updated focal length, principal point offsets and Exterior Orientationparameters. First, a Digital Terrain/Surface Model (DTM/DSM) was extracted from the stereo imagery, following which the rawimages were orthorectified to produce an orthomosaic product

the international archives of the photogrammetry, remote sensing and spatial information sciences/international archives of the photogrammetry, remote sensing and spatial information sciences

ACCURACY ASSESSMENT OF DIRECT GEOREFERENCING FOR PHOTOGRAMMETRIC APPLICATIONS ON SMALL UNMANNED AERIAL PLATFORMS