Integrating UAV-based Lidar and Photogrammetry

Dense 3D Point Cloud Generation with Ultra-high Precision

Recent unmanned aerial vehicle (UAV or ‘drone’) platforms jointly collect imagery and Lidar data. Their combined evaluation potentially generates 3D point clouds at accuracies and resolutions of some millimetres, so far limited to terrestrial data capture. This article outlines a project that integrates photogrammetric bundle block adjustment with direct georeferencing of Lidar point clouds to improve the respective accuracy by an order of magnitude. Further benefits of combined processing result from adding Lidar range measurement to multi-view-stereo (MVS) image matching during the generation of high-precision dense 3D point clouds. The project was aimed at the area-covering monitoring of potential subsidence... (read more)

2020-05-19 02:33:35

GCPs for Satellite Image Georeferencing Surveyed Worldwide with GNSS PPP

GNSS positioning by precise point positioning (PPP) has developed over the last few years and is frequently used by the scientific community. Its real-time or post-processing applications are already used in several fields (e.g. in farming for tractor guidance or in aerial survey for calculating flight paths), but despite this its use remains relatively low with surveyors, mainly due to the initialisation time. This method, however, can prove to be effective, particularly in regions where there are no or few permanent GNSS stations (CORS) to establish a geodetic survey traverse and fix ground control points (GCPs) for aerial or satellite... (read more)

2016-11-14 09:12:11

Continuous Mobile Laser Scanning

Mobile Platform Terrestrial Lidar, IMU and GPS

Combining Terrestrial Laser Scanning, Position and Orientation Systems and GPS receivers into a mobile mapping system enables effective mapping of large and complex terrain. The authors tested a mobile mapping system at two sites: in an open pit mine, and along a road.<P> Optech and Sineco have been developing a mobile mapping system, initially based on a platform combining the ILRIS-3D (Intelligent Laser Ranging and Imaging System), the Applanix POS LV (land-based vehicle) and GPS receivers. This new system, ILRIS-MC (Motion Compensation), can be installed on any mobile platform and performs fast surveys, generating point-clouds in real time in WGS84... (read more)

2007-12-08 12:00:00

Underground Mobile Mapping Platform from Japan

Common mobile mapping systems heavily rely on positioning using GNSS. However, concrete, soil and other materials block GNSS signals, thus impeding their use when inspecting pipelines, subways or other underground corridors. Furthermore, such corridors are often narrow, which requires the system to be compact. In Japan a platform equipped with laser scanners and a camera which has been developed for mapping a wide variety of narrow underground spaces. (By Katsuhisa Banjo, ASCO, Japan) Regular inspection of underground corridors is important to detect deformations and damage. The success of above-ground mobile mapping systems (MMSs) triggered us to design an MMS... (read more)

2014-06-10 11:25:12

Geokosmos Conducts French Railways Lidar Survey

Geokosmos (Russia) has completed Lidar survey of French national railways in France., using combined airborne laser scanning and digital aerial photography technology. The company surveyed that part of the railroads which connects Amiens and Bouillon and covers an area of 83km. The captured data was used for producing a large-scale digital topographic map (scale 1:500) and a digital orthophoto (GSD 5cm) that will help French National Railways Service provide technical assessment of the French railways and its infrastructure. Given tough requirements set up by the customer with regards to the accuracy of captured data, aerial laser scanning combined with aerial digital photography... (read more)

2007-07-17 10:08:50

GNSS Handheld Data Collector

Nexteq Navigation, Canada, has announced the T5A multifunctional GNSS handheld data collector. This device is a high-accuracy GPS unit capable of 2.0cm accuracy using Real Time Kinematics (RTK) and 50cm globally using Nexteq’s i-PPP technology. The T5A combines its centimetre-level precision with a versatility allowing for accurate data collection in various weather conditions. The T5A is equipped with a 3.7” colour touch screen that is with its IP66 rating both waterproof and dustproof and includes features such as Bluetooth, Wi-Fi, digital cellular data and voice, microSD card slots and a 3.0 megapixel digital camera. Like all Nexteq Navigation GPS handhelds,... (read more)

2012-06-05 12:00:00

Correlator3D for Quebec

The Geomatics Centre of Quebec (CGQ, Canada) has completed a major mapping project using SimActive Correlator3D. The project was done in collaboration with the Nippour Group, whose responsibilities included extensive quality assurance. The project involved processing more than 2,200 scanned films at 21cm ground sampling distance (GSD) and generating digital surface / terrain models (DSM/DTM) with 1m grid post spacing. More than 350,000 ground control points were then collected through real-time kinematic GPS by Nippour, and the average vertical error of the final DTM was shown to be less than 27cm. Professionals who like to experience a live... (read more)

2011-04-27 11:33:38

Laser Digital Theodolite with 600m Range

Sokkia Topcon releases the LDT520, a new 5" digital theodolite equipped with a telescope with laser beam emission capability. Representing a significant evolution over the previous model LDT50, the LDT520 boasts the world's longest laser range, class-topping dust and water protection, and a continuous operation time over 2.5 times that of its predecessor. Other improvements over the previous model are a better protection against dust and water (IP66), absolute encoders providing 5" angle accuracy, a longer battery life (up to 12.5 hours at maximum output) and reduction of the optical plummet to 15cm instead of 20cm of the previous... (read more)

2008-12-09 12:20:58

NavCom Releases SF-2110M and SF-2110R Modular L1 GPS and StarFire Receivers

NavCom Technology, Inc. (CA, USA) has released the SF-2110M and SF-2110R modular L1 StarFire GPS receivers. Using StarFire NavCom's SF-2110M and SF-2110R receivers provide instantaneous 50cm accuracy. The SF-2110M utilises a compact dual-band antenna capable of receiving GPS and StarFire signals. This antenna provides phase center stability in a small, robust, lightweight format. The SF-2110R includes a separate L-Band antenna for enhanced StarFire signal reception in challenging environments and at high latitudes. Coupled with NavCom's StarFire subscription service, the SF-2110 delivers 50cm position fixes without the use of a second receiver serving as a base station. NavCom's SF-2110 series of... (read more)

2007-08-27 09:25:38

Indoors

Knowing where one is inside an office, shopping centre or other giant building, and how to get to where one wants to be, is key for fire fighters, medical personnel and other rescuers in a crisis situation. When a building is on fire rescuers don’t have time to study floor plans by entrance or elevators, and the receptionist will have fled to save her own life. Mobile GIS handhelds, equipped with GNSS, might provide a solution. However, on entering a building a GNSS receiver will fail to maintain tracking position. It is not the wavelength that foils GNSS signal take-up,... (read more)

2011-04-27 02:35:35