Airborne LiDAR is one of the most effective and reliable means of terrain data collection. Using LiDAR data for DEM generation is becoming a standard practice in spatial related areas. However, the effective processing of the raw LiDAR data and the generation of an efficient and high-quality DEM remain big challenges. This paper reviews the recent advances of airborne LiDAR systems and the use of
LiDAR data for DEM generation, with special focus on LiDAR data filters, interpolation methods, DEM resolution, and LiDAR data reduction. Separating LiDAR points into ground and non-ground is the most critical and difficult step for
DEM generation from LiDAR data. Commonly used and most recently developed LiDAR filtering methods are presented. Interpolation methods and choices of suitable interpolator and DEM resolution for LiDAR DEM generation are discussed in detail. In order to reduce the data redundancy and increase the efficiency in terms of storage
and manipulation, LiDAR data reduction is required in the process of DEM generation. Feature specific elements such as breaklines contribute significantly to DEM quality. Therefore, data reduction should be conducted in such a way that critical elements are kept while less important elements are removed. Given the highdensity
characteristic of LiDAR data, breaklines can be directly extracted from LiDAR data. Extraction of breaklines and integration of the breaklines into DEM generation are presented.

/pdf/airborne-lidar-for-dem-generation-some-critical-issues-sxb3b6yug9.pdf

Airborne LiDAR for DEM generation: some critical issues

Digital terrain representation. Data Acquisition Methodology. Terrain Surface Modeling (Reconstruction). Algorithms for Triangular Irregular Network Formation. Interpolation Methods. Data Quality Control. Mathematical Models for DTM Accuracy.Multi-Scale Representation of Digital Elevation Models. DTM Data Management. Contouring from DTM. DTM-Based Terrain Analysis (DTM Interpretation). Visualization of DTM Surface. Applications. Integration with GIS. Index.

Digital Terrain Modeling: Principles and Methodology

In-car positioning and navigation has been a killer application for Global Positioning System (GPS) receivers, and a variety of electronics for consumers and professionals have been launched on a large scale. Positioning technologies based on stand-alone GPS receivers are vulnerable and, thus, have to be supported by additional information sources to obtain the desired accuracy, integrity, availability, and continuity of service. A survey of the information sources and information fusion technologies used in current in-car navigation systems is presented. The pros and cons of the four commonly used information sources, namely, 1) receivers for radio-based positioning using satellites, 2) vehicle motion sensors, 3) vehicle models, and 4) digital map information, are described. Common filters to combine the information from the various sources are discussed. The expansion of the number of satellites and the number of satellite systems, with their usage of available radio spectrum, is an enabler for further development, in combination with the rapid development of microelectromechanical inertial sensors and refined digital maps.

In-Car Positioning and Navigation Technologies—A Survey

The quality and future of human existence are directly related to the condition of our natural environment, but we are damaging the environment. Scientific evidence has mounted a compelling case that human behavior is responsible for deterioration in the Earth's natural environment, with the rate of deterioration predicted to increase in the future. Acknowledging this evidence, the governments of 192 countries have formally agreed to take action to resolve problems with the climate system, one of the most highly stressed parts of the natural environment. While the intention is clear, the question of how best to proceed is not.

The research reported here undertook a three-phase approach of selecting, analyzing, and synthesizing relevant literature to develop a holistic, transdisciplinary, integrative framework for IT-enabled business transformation. The focus on business transformation is because business is recognized as being a critical contributor in realizing the challenges of environmental sustainability due to its potential capacity for innovation and change-locally, nationally, and globally. This article also serves as a resource base for researchers to begin to undertake significant information systems and multidisciplinary work toward the goal of environmental sustainability. Through selection and analysis of illustrative examples of current work from 12 academic disciplines across 6 core categories, the framework addresses the key issues of uncertainty:

(1) What is meant by environmental sustainability?

(2) What are its major challenges?

(3) What is being done about these challenges?

(4) What needs to be done?

http://ftp.misq.org/skin/frontend/default/misq/pdf/appendices/2011/ElliotAppendices.pdf

Transdisciplinary perspectives on environmental sustainability: a resource base and framework for IT-enabled business transformation

Urban land cover classification using airborne LiDAR data: A review

Using IT approaches to promote public participation in renewable energy planning: Prospects and challenges

Growth in the available quantities of digital geographical data has led to major problems in maintaining and integrating data from multiple sources, required by users at differing levels of generalization. Existing GIS and associated database management systems provide few facilities specifically intended for handling spatial data at multiple scales and require time consuming manual intervention to control update and retain consistency between representations. In this paper the GEODYSSEY conceptual design for a multi-scale, multiple representation spatial database is presented and the results of experimental implementation of several aspects of the design are described. Object-oriented, deductive and procedural programming techniques have been applied in several contexts: automated update software, using probabilistic reasoning; deductive query processing using explicit stored semantic and spatial relations combined with geometric data; multiresolution spatial data access methods combining poini,...

Database design for a multi-scale spatial information system

The fundamental aim of a digital elevation model (DEM) is to represent a surface accurately, such that elevations can be estimated for any given location. It is, therefore, necessary to have efficient and precise algorithms for the computation of surface elevations between given points. The hypothesis presented here, is that higher-order interpolation techniques will always be more accurate than the likes of the popular bilinear algorithm. This hypothesis will be evaluated through an assessment of the accuracy with which DEMs can be interpolated to higher spatial resolutions. A variety of interpolation techniques are assessed, ranging from the one-term level plane to the 36-term biquintic polynomial. In general, techniques that take account of the local terrain neighbourhood are more consistent and accurate, reducing the rms. error by up to 20% of the bilinear interpolant.

Higher-order interpolation of regular grid digital elevation models

Accuracy and reliability of map-matched GPS coordinates: the dependence on terrain model resolution and interpolation algorithm

This paper describes an automated method for predicting the number of satellites visible to a GPS receiver, at any point on the Earth's surface at any time. Intervisibility analysis between a GPS receiver and each potentially visible GPS satellite is performed using a number of different surface models and satellite orbit calculations. The developed software can work with various ephemeris data, and will compute satellite visibility in real time. Real-time satellite availability prediction is very useful for mobile applications such as in-car navigation systems, personal navigations systems and LBS. The implementation of the method is described and the results are reported.

/pdf/modelling-and-prediction-of-gps-availability-with-digital-2p0ee7mubh.pdf

David B. Kidner

Papers

Using IT approaches to promote public participation in renewable energy planning: Prospects and challenges

Database design for a multi-scale spatial information system

Higher-order interpolation of regular grid digital elevation models

Accuracy and reliability of map-matched GPS coordinates: the dependence on terrain model resolution and interpolation algorithm

Modelling and prediction of GPS availability with digital photogrammetry and LiDAR