Precise Point Positioning from Combined GNSS

Fugro Marinestar G4+ PPP-RTK Developments
Currently there are four global navigation satellite systems (GNSSs) available: GPS, Glonass, BeiDou and Galileo. The satellites of these systems are used for positioning, and the accuracy is greatly improved if precise satellite orbit, clock and uncalibrated phase delay (UPD) corrections are available when using the precise point positioning (PPP) technique. Fugro operates a worldwide network of reference stations capable of tracking GPS, Glonass, BeiDou and Galileo systems. This network is used to calculate precise satellite orbit and clock corrections of all four constellations in real time for maritime applications. The corrections are broadcast to users by eight geostationary L-band... (read more)
2017-02-06 10:20:00

Indoor Positioning

Technologies, Features and Prospects
Outdoor positioning and navigation techniques using GNSS have been well explored and are now a vital part of daily life all over the planet. Since GNSS was initially designed to support the military during open-air combat, there was no need for the signals to be able to pass through walls and roofs. Indoor positioning therefore requires the alternatives to GNSS. How can geomatics contribute to the deployment of indoor positioning solutions? In aiming to find answers to that question, this article also examines current technologies and the various types of applications they originate from. An indoor positioning system is a... (read more)
2013-10-28 01:54:29

UAS-supported Agriculture: Still for Innovators

Greatest Potential on Small Farms
While unmanned aerial systems offer huge possibilities in modern farming, most of them lie in the future. These airborne vehicles currently mainly deliver images that are subsequently combined with other input in the farm-specific management system. In the future they will be able to contribute to land management and individual crop-product delivery based on real-time analysis. Another very promising segment for UAS-supported precision agriculture is water management. Precision agriculture is a relatively young concept, dating from around the turn of this century. The first products were focused on add-on guiding systems for tractors. These give a good return on investment,... (read more)
2016-04-28 10:30:33

Towards Optimal 3D Point Clouds

Automation in 3D Mobile Laser Scanning
Motivated by the increasing need of rapid characterisation of environments in 3D, the authors have designed a robot system that automates the work of an operator of terrestrial laser scanners. The built system makes it possible to work without markers or targets, saving surveyors more than 75% of the time spent in the field. Another impulse for developing the platform was the demand for a remote inspection tool. The robot is capable of surveying remote sites or danger areas, such as plants, underground mines, tunnels, caves or channels. The availability of the robotic platform further enables the study of mobile... (read more)
2013-10-28 11:30:47

Linking Geospatial Database with GIS

GIM International Interviews Dr Jayant Sharma, Technical Director Spatial Products, Oracle
The database vendor Oracle Corporation has for a long time shown a strong interest in geospatial data storage. For a fuller picture of the spatial aspects of their latest product, Oracle 10g, GIM International interviewed Dr Jayant Sharma, technical director of Oracle Spatial Products, in New Delhi, India. Biography of Dr Sharma Dr Jayant Sharma is technical director, spatial products at Oracle's New England Development Center and has over a decade experience in databases and spatial information systems. He was responsible for building the spatial product team when he joined Oracle Corporation in 1996. He also represents Oracle at Open... (read more)
2005-06-09 12:00:00

Geo-ethics Requires Prudence with Private Data

GIM International interviews Professor Yola Georgiadou
In today’s datafying world, we continuously leave – unintentionally – digital traces of our daily lives. These traces can reveal a lot about us, our beliefs and our actions to parties who are not the intended recipients of such information. In May this year, Professor Yola Georgiadou held a compelling keynote speech during the FIG Working Week in Helsinki. She called for prudent use of data acquired during the rapid land surveying of developing countries and for action to protect citizens’ privacy. 'GIM International' talked to her about the topic that has become so dear to her: ‘geo-ethics’. What actually is... (read more)
2017-10-05 11:42:20

Mapping an Oil Pipeline

DEMs and Ortho-imagery for Colombia from Dual-band Side-looking Radar
Adverse weather and terrain conditions meant the Cano-Limon oil pipeline in Colombia had never been accurately mapped until orthorectified images and digital elevation models covering an area of 94,000km2 were created using airborne dual-band interferometric IFSAR simultaneously acquired X and P-band data. The authors report on main aspects of the project. The Cano-Limon oil pipeline extends nearly 780km from the Cano-Limon oilfield in Colombia’s Arauca region along the north-western border with Venezuela to a port in Covenas. When fully operational the pipeline can carry up to 20% of Colombian petroleum production, a major source of national revenue. In collaboration with... (read more)
2006-07-24 12:00:00

BIM: A New Model for Surveyors

Important Opportunities and Challenges for Surveyors
Building information modelling (BIM) is one of the most intriguing opportunities for surveyors to come along in years. This model-based approach combines technologies and processes to support the efficient creation and use of information for building construction and operations. Because of its strong ties to spatial information, BIM offers a familiar landscape and rich possibilities for surveyors and other geospatial professionals, according to Ron Bisio, vice president of Trimble Geospatial. The opportunities stem from the growing acceptance of BIM within the surveyor’s traditional client base of engineers, architects and property owners. By gaining an understanding of the key concepts of... (read more)
2017-02-28 12:59:59

Multi-level Implementation of SDIs

Emerging Trends and Key Strategic Issues
The debate on Spatial Data Infrastructures (SDI) has reached a level of maturity that encourages reflection and facilitates evaluation of past experience. The author considers some emerging trends in the field of SDI with reference to recent implementation, and reformulates four key strategic issues for future SDI development identified in GIM International several years ago. The largest change is the shift from the product model of the first-generation SDIs to a process-led model of second-generation SDI, essentially a shift in emphasis from the concerns of data producers to those of data users. Database creation was very much the key driver... (read more)
2006-02-23 12:00:00

Towards All-in-one Photogrammetry

A Case Study of Dense Image Matching Using Oblique Imagery
Modern photogrammetric camera architectures provide high-resolution imagery in nadir and oblique views. This case study sets out to prove the potential of oblique imagery to deliver dense point clouds to be used for DEM, 3D city model and true orthophoto generation – an important step towards ‘all-in-one’ photogrammetry. 3D point clouds for DEM or orthophoto production are typically collected using airborne Lidar systems. The recent development of dense image matching methods provides an efficient alternative by deriving point clouds from imagery. Within this fully automated image processing pipeline, corresponding pixels between multiple images are determined. Each pixel represents a sight... (read more)
2012-04-26 11:32:21
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