Geoffrey J Hay

Geoffrey J Hay
The University of Calgary | HBI · Department of Geography

PhD Landscape Ecology
Always seeking great students and innovative colleagues.

About

95
Publications
51,799
Reads
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7,332
Citations
Introduction
Dr Geoff Hay, is a full Professor in GIScience. His long-term research program is titled “The Remote Sensing of Urban Energy Efficiency.” It involves the use of high-resolution Thermal Infrared (TIR) imagery, geographic object-based image analysis (GEOBIA), machine learning, GIS and geo-spatial analysis to accurately define urban energy efficiency from space. His award winning research has been commercialized as MyHEAT Inc (https://www.myheat.ca).
Additional affiliations
April 2011 - present
The University of Calgary
Position
  • Professor (Associate)
June 2005 - June 2011
The University of Calgary
Position
  • Research Assistant
Description
  • Dr Hay joined the University of Calgary, Department of Geography in June 2005, and was promoted to Associate Professor in April 2011, and became an ISEEE Fellow in June, 2011.

Publications

Publications (95)
Article
Full-text available
Geographic object-based image analysis (GEOBIA) is a remote sensing image analysis paradigm that defines and examines image-objects: groups of neighboring pixels that represent realworld geographic objects. Recent reviews have examined methodological considerations and highlighted how GEOBIA improves upon the 30+ year pixel-based approach, particul...
Article
Full-text available
The primary goal of collecting Earth observation (EO) imagery is to map, analyze, and contribute to an understanding of the status and dynamics of geographic phenomena. In geographic information science (GIScience), the term object-based image analysis (OBIA) was tentatively introduced in 2006. When it was re-formulated in 2008 as geographic object...
Article
Full-text available
The objective of this study is to evaluate operational methods for creating a particular type of urban vegetation map—one focused on vegetation over rooftops (VOR), specifically trees that extend over urban residential buildings. A key constraint was the use of passive remote sensing data only. To achieve this, we (1) conduct a review of the urban...
Conference Paper
Full-text available
The primary aim of image data collection is to extract information from imagery and turn scene content into knowledge. In Geographic Information Science (GIScience), the term "object-based image analysis" (OBIA) was tentatively introduced in 2006. When it was re-formulated in 2008 as GEOBIA, the primary focus was set on Earth data-derived applicati...
Article
Over the last two decades (since circa 2000), Geographic Object-Based Image Analysis (GEOBIA) has emerged as a new paradigm to analyzing high-spatial resolution remote sensing imagery. During this time, research interests have demonstrated a shift from the development of GEOBIA theoretical foundations to advanced geo-object-based models and their i...
Article
Green roofs are becoming increasingly popular for moderating stormwater runoff in urban areas. This study investigated the impact different climates have on the retention performance of identical green roofs installed in London Ontario (humid continental), Calgary Alberta (semi-arid, continental), and Halifax Nova Scotia (humid, maritime). Drier cl...
Article
High-spatial and -radiometric resolution (H-res) thermal infrared (TIR) airborne imagery, such as the TABI-1800 (Thermal Airborne Broadband Imager) provide unique surface temperature information that can be used for urban heat loss mapping, heat island analysis, and landcover classifications. For mapping large urban areas at a high-spatial resoluti...
Article
Full-text available
Thermal Infrared (TIR) remote sensing images of urban environments are increasingly available from airborne and satellite platforms. However, limited access to high-spatial resolution (H-res: similar to 1 m) TIR satellite images requires the use of TIR airborne sensors for mapping large complex urban surfaces, especially at micro-scales. A critical...
Article
Full-text available
The Heat Energy Assessment Technologies (HEAT) project uses high-resolution airborne thermal imagery, Geographic Object-Based Image Analysis (GEOBIA), and a Geoweb environment to allow the residents of Calgary, Alberta, Canada to visualize the amount and location of waste heat leaving their houses, communities, and the city. To ensure the accuracy...
Article
Full-text available
In an effort to minimize complex urban microclimatic variability within high-resolution (H-Res) airborne thermal infrared (TIR) flight-lines, we describe the Thermal Urban Road Normalization (TURN) algorithm, which is based on the idea of pseudo invariant features. By assuming a homogeneous road temperature within a TIR scene, we hypothesize that a...
Article
Au cours de la dernière décennie, le problème d'échelle a attiré l'attention d'un nombre croissant de chercheurs de diverses disciplines. Il a été fortement suggéré qu'une science de l'échelle soit établie. Alors qu'il est largement reconnu que la télédétection peut apporter une contribution significative au problème d'échelle, très peu d'études on...
Article
Full-text available
a b s t r a c t The amount of scientific literature on (Geographic) Object-based Image Analysis – GEOBIA has been and still is sharply increasing. These approaches to analysing imagery have antecedents in earlier research on image segmentation and use GIS-like spatial analysis within classification and feature extraction approaches. This article in...
Article
The amount of scientific literature on (Geographic) Object-based Image Analysis – GEOBIA has been and still is sharply increasing. These approaches to analysing imagery have antecedents in earlier research on image segmentation and use GIS-like spatial analysis within classification and feature extraction approaches. This article investigates these...
Chapter
What does a scale-domain look like; where is it located, and how can we visualize it? To answer these questions, we describe a novel geo-object-based framework that integrates Hierarchy theory and Linear Scale-Space (SS) for automatically visualizing and modeling landscape scale-domains over multiple scales. By integrating concepts from Hierarchy t...
Article
As part of the Heat Energy Assessment Technologies (HEAT) project, we describe a novel geographic object-based mosaicing algorithm referred to as Object-Based Mosaicing (OBM) that joins thermal airborne flight lines around urban roof objects rather than bisecting them with arbitrary mosaic join lines. An OBM mosaic is compared with a “traditional”...
Article
Characterizations of land-cover dynamics are among the most important applications of Earth observation data, providing insights into management, policy and science. Recent progress in remote sensing and associated digital image processing offers unprecedented opportunities to detect changes in land cover more accurately over increasingly large are...
Article
Geographically weighted regression (GWR) extends the conventional ordinary least squares (OLS) regression technique by considering spatial nonstationarity in variable relationships and allowing the use of spatially varying coefficients in linear models. Previous forest studies have demonstrated the better performance of GWR compared to OLS when cal...
Article
The GEOgraphic Object-Based Image Analysis (GEOBIA) paradigm continues to prove its efficacy in remote sensing image analysis by providing tools which emulate human perception and combine analyst's experience with meaningful image-objects. However, challenges remain in the evolution of this new paradigm as sophisticated methods attempt to deliver o...
Article
Full-text available
THIS PAPER CAN BE FREELY DOWNLOADED here: http://www.mdpi.com/2072-4292/3/7/1380/pdf The HEAT (Home Energy Assessment Technologies) pilot project is a FREE Geoweb mapping service, designed to empower the urban energy efficiency movement by allowing residents to visualize the amount and location of waste heat leaving their homes and communities as...
Article
Full-text available
Cities are complex systems composed of numerous interacting components that evolve over multiple spatio-temporal scales. Consequently, no single data source is sufficient to satisfy the information needs required to map, monitor, model, and ultimately understand and manage our interaction within such urban systems. Remote sensing technology provide...
Article
A potential solution to reduce high acquisition costs for airborne lidar (light detection and ranging) data is to combine lidar transects and optical satellite imagery to characterize forest vertical structure. Although multiple regression is typically used for such modeling, it seldom fully captures the complex relationships between forest variabl...
Article
Lidar (light detection and ranging) has demonstrated the ability to provide highly accurate information on forest vertical structure; however, lidar data collection and processing are still expensive. Very high spatial resolution optical remotely sensed data have also shown promising results to delineate various forest biophysical properties. In th...
Conference Paper
Lidar (light detection and ranging) remote sensing can accurately characterize forest vertical structure, such as canopy height, above-ground biomass (AGB) and timber volume; however, data acquisition is expensive. To reduce costs, one potential method is to integrate (small area) lidar transects and (large extent) optical imagery to estimate fores...
Article
Home Energy Assessment Technologies (HEAT) represents software, hardware, data provision and web-portal service that enables free-of-charge, automatic assessment of domestic waste-heat footprints by simply clicking on the house in Google Maps. HEAT aims at providing Calgary waste heat data that is timely, in-depth, easy to use and location-specific...
Article
Full-text available
The objectives of this study were (a) to evaluate the suitability of SAR imagery for discriminating savanna physiognomies, (b) to combine SAR and optical imagery for achieving improved accuracy, and (c) to develop a hybrid approach based on pixels and objects to characterize gradients of vegetation density. We used imagery from the Phased Array L-b...
Article
Numerous applications of small footprint airborne lidar (light detection and ranging) have provided highly accurate results for estimating forest height. However, the associated acquisition cost remains high, which limits its use for wall-to-wall large area mapping. In this study, we developed a novel framework by integrating GEOBIA (GEOgraphic Obj...
Article
We report on the HEAT (Home Energy Assessment Technologies) pilot project conducted over the City of Calgary, Alberta, Canada, and discuss plans for the 2010 full city implementation. HEAT represents a Free and Open Source (FOSS) Geomatics solution for residential waste heat monitor with high-resolution airborne thermal imagery that is intended to...
Article
Full-text available
We report on the HEAT (Home Energy Assessment Technologies) pilot project conducted over the city of Calgary, Alberta, Canada and discuss plans for the 2010 full city implementation. The objective of HEAT is to provide free web tools to (i) evaluate and monitor residential thermal envelopes (i.e., waste heat) using a Thermal Airborne Broadband Imag...
Article
Full-text available
We argue that thematic resolution, i.e., the level of categorical detail of a thematic map expressed by the number of classes included in the map legend, is an inherent component of the scale at which a landscape is analyzed. Changing the number of classes can change the configuration of the patch mosaic as much as changing the grain does. We addre...
Article
LiDAR canopy height models (CHMs) can exhibit unnatural looking holes or pits, i.e., pixels with a much lower digital number than their immediate neighbors. These artifacts may be caused by a combination of factors, from data acquisition to post-processing, that not only result in a noisy appearance to the CHM but may also limit semi-automated tree...
Article
Full-text available
Geographic Information tools (GI tools) have become an essential component of research in landscape ecology. In this article we review the use of GIS (Geographic Information Systems) and GI tools in landscape ecology, with an emphasis on free and open source software (FOSS) projects. Specifically, we introduce the background and terms related to th...
Article
Full-text available
We introduce an automated change detection and delineation tool for remote sensing images: the Land-cover Change Mapper (LCM). LCM rapidly generates a polygon vector layer (shapefile) of regions deemed to have undergone significant change in land-cover. In its simplest usage, LCM requires two single band or multi-band co-registered images of the sa...
Chapter
Full-text available
Forest monitoring information needs span a range of spatial, spectral and temporal scales. Forest management and monitoring are typically enabled through the collection and interpretation of air photos, upon which spatial units are manually delineated representing areas that are homogeneous in attribution and sufficiently distinct from neighboring...
Conference Paper
Full-text available
KEY WORDS: Canopy height, Geographic object-based image analysis (GEOBIA), Geographic object-based texture (GEOTEX), Tree-ray-shadow geometry (TG), Quickbird, Lidar ABSTRACT: Canopy surface height (CSH) is a significant forest biophysical parameter to estimate above-ground biomass and carbon content. High-spatial resolution optical remotely sensed...
Article
Full-text available
The manual delineation of vegetation patches or forest stands is a costly and crucial stage in any land-cover mapping project or forest inventory based upon photointerpretation. Recent computer techniques have eased the task of the interpreter; however, a good deal of craftsmanship is still required in the delineation. In an effort to contribute to...
Article
Full-text available
High spatial resolution satellite imagery, with pixel sizes of one metre or less, are increasingly available. These data provide an accessible and flexible source of information for forest inventory purposes. In addition, the digital nature of these data provides an opportunity for automated and computer-assisted approaches for forest stand delinea...
Chapter
Full-text available
Object-Based Image Analysis (OBIA) has gained considerable impetus over the last decade. However, despite the many newly developed methods and the numerous successful case studies, little effort has been directed towards building the conceptual foundations underlying it. In particular, there are at least two questions that need a clear answer befor...
Chapter
Full-text available
What is Geographic Object-Based Image Analysis (GEOBIA)? To answer this we provide a formal definition of GEOBIA, present a brief account of its coining, and propose a key objective for this new discipline. We then, conduct a SWOT1 analysis of its potential, and discuss its main tenets and plausible future. Much still remains to be accomplished.
Book
Advances in earth observations sensors and GIScience have led to the emerging fields of Object-based Image Analysis (OBIA). The need for timely and accurate geo-spatial information is steadily increasing. This book discusses means, technologies and approaches related to the processing and analysis of multi-sensor, multi-resolution data with a focus...
Chapter
Full-text available
The process of cartographic generalization requires that extraordinary and typical geographical structures be maintained. We have set-up a pencil and paper experiment to analyze what extra-ordinary structures, i.e., groups of polygons, are perceived by humans, and to explore the principles that lead to the visual grouping of polygonal objects. In t...
Article
Full-text available
What is Geographic Object-Based Image Analysis (GEOBIA)? To answer this we provide a formal definition of GEOBIA, present a brief account of its coining, and propose a key objective for this new discipline. We then, conduct a SWOT¹analysis of its potential, and discuss its main tenets and plausible future. Much still remains to be accomplished.
Article
Forest monitoring information needs span a range of spatial, spectral and temporal scales. Forest management and monitoring are typically enabled through the collection and interpretation of air photos, upon which spatial units are manually delineated representing areas that are homogeneous in attribution and sufficiently distinct from neighboring...
Article
Object-Based Image Analysis (OBIA) has gained considerable impetus over the last decade. However, despite the many newly developed methods and the numerous successful case studies, little effort has been directed towards building the conceptual foundations underlying it. In particular, there are at least two questions that need a clear answer befor...
Article
Full-text available
This paper deals with the description and assessment of uncertainties in land use data derived from Remote Sensing observations, in the context of hydrological studies. Land use is a categorical regionalised variable reporting the main socio-economic role each location has, where the role is inferred from the pattern of occupation of land. The prop...
Chapter
Full-text available
It is now widely recognized that landscapes are complex systems that are characterized by a large number of heterogeneous spatial components, nonlinear interactions, emergence, self-organization, adaptation through time, and scale multiplicity. The later property refers to the fact that landscapes exhibit distinctive spatial patterns associated to...
Conference Paper
Full-text available
Large area thematic mapping is usually performed through the digital classification of satellite imagery. Regardless of the method selected, pixel-wise classified images typically suffer from 'salt and pepper' noise that hinders raster to vector conversion. In order to enable a correct vectorization, classified images require a post- processing ste...
Conference Paper
Full-text available
The manual delineation of vegetation patches or forest stands is a costly and critical stage in any landcover mapping project or forest inventory based upon photointerpretation. Recent computer techniques have eased the task of the interpreter; however a good deal of craftsmanship is still required in the delineation. In an effort to contribute to...
Article
The views of several authors on the effectiveness of enhanced thermodynamic modeling equation of state platform to address the challenges of accurate simulation of oil and natural gas production, are presented. Cubic equations of state are used to model thermodynamic equilibrium and physical properties of hydrocarbon systems as they provide a compa...
Conference Paper
Full-text available
As an emerging discipline, we propose a formal definition of OBIA, describe how OBIA came into existence, and as a road map to future research propose a fundamental objective. In order to provide potential strategies to meet this objective, we undertake a tentative SWOT Analysis to identify current Strengths, Weakness, Opportunities and Threats tha...
Article
Over the last decade the analysis of Earth observation data has evolved from what were predominantly per-pixel multispectral-based approaches, to the development and application of multiscale object-based methods. To empower users with these emerging object-based approaches, methods need to be intuitive, easy to use, require little user interventio...
Article
This paper describes an application of fuzzy logic to noise rejection in a control loop. This new use of fuzzy logic solves the problem of sluggish control loop response when using a set-point range to stop constant valve chattering due to noise in the output signal being sent to a control valve. Multiple related variables and a general understandi...
Article
The methodology used to develop an operator training interface using a rigorous steady state simulator in conjunction with linear first and second order dynamic models has been discussed. This approach provided a means to illustrate overall process behavior in addition to coupled and non-linear trends in the process. This was accomplished by updati...
Article
This paper describes a nonintrusive plant analysis technique for variable pairing that relies on power spectrum frequency analysis. The development of the method is described and guidelines for the implementation of the method are presented. Information gathered from the frequency analysis is used in variable pairing to ensure minimal impacts from...
Article
The implementation of an online optimizer, using a steady state simulator, can produce many challenges as well as yield many advantages. For the creation of a matching process model simulation and to ensure good results, the user should check and verify this model for all ranges of expected operating conditions. Values used from a converged steady...
Article
Hierarchies of superimposed structures are found in maps of geological horizons in sedimentary basins. Mapping based on three-dimensional (3D) seismic data includes structures that range in scale from tens of metres to hundreds of kilometres. Extraction of structures from these maps without a priori knowledge of scale and shape is analogous to patt...
Article
Extracting information on geological structures at multiple scales from 2D surfaces and 3D seismic volumes.
Article
Full-text available
Complex systems, such as landscapes, are composed of different critical levels of organization where interactions are stronger within levels than among levels, and where each level operates at relatively distinct time and spatial scales. To detect significant features occurring at specific levels of organization in a landscape, two steps are requir...
Article
Full-text available
Based on a series of empirical studies beginning in the 1970's, it was noted that remote sensing data suffered from the scale and aggregation problem. It was further recognized that there was no unique or 'optimal' spatial resolution for detecting the different sized, shaped, and spatially arranged entities represented in a remote sensing image of...
Article
Landscape spatial pattern is dependent not only on interacting physiographic and physiological processes, but also on the temporal and spatial scales at which the resulting patterns are assessed. To detect significant spatial changes occurring through space and time three fundamental components are required. First, a multiscale dataset must be gene...
Article
Within the conceptual framework of Complex Systems, we discuss the importance and challenges in extracting and linking multiscale objects from high-resolution remote sensing imagery to improve the monitoring, modeling and management of complex landscapes. In particular, we emphasize that remote sensing data are a particular case of the modifiable a...
Article
Over the last two decades, the scale-space community has developed into a reputable field in computer vision, yet its nontrivial mathematics (i.e. group invariance, differential geometry and tensor analysis) limit its adoption by a larger body of researchers and scientists, whose interests in multiscale analysis range from biomedical imaging to lan...
Article
Full-text available
In this paper we describe a novel integration of Hierarchy Theory and Linear Scale-Space for automatically visualizing, and modeling dominant landscape structures at multiple scales. Specifically, we describe 3D methods for modelling and visualizing landscape scale-domains by using scale-space events as critical domain thresholds. This novel approa...