title: Maximizing precision over extended unambiguous range for TOF range imaging systems

authors: Jongenelen, Adrian P.P.

subjects: range imaging

abstract: The maximum unambiguous range for time-of-flight range imaging systems is inversely proportional to the chosen modulation frequency. However, increasing the unambiguous range by decreasing the modulation frequency will generally also degrade the range measurement precision. We describe a technique that significantly extends the range of a time-of-flight imaging system without compromising range precision. This is achieved by employing two modulation frequencies simultaneously. The chosen frequencies can be a combination of high and low frequency, or two similarly high frequencies. In this paper we present experimental results comparing single frequency; dual high and low frequency; and dual high frequency operation and demonstrate that range precision need not be appreciably compromised to achieve an extended unambiguous range.

text: Maximizing precision over extended unambiguous range for TOF range imaging systems The maximum unambiguous range for time-of-flight range imaging systems is inversely proportional to the chosen modulation frequency. However, increasing the unambiguous range by decreasing the modulation frequency will generally also degrade the range measurement precision. We describe a technique that significantly extends the range of a time-of-flight imaging system without compromising range precision. This is achieved by employing two modulation frequencies simultaneously. The chosen frequencies can be a combination of high and low frequency, or two similarly high frequencies. In this paper we present experimental results comparing single frequency; dual high and low frequency; and dual high frequency operation and demonstrate that range precision need not be appreciably compromised to achieve an extended unambiguous range.

year: 2010

title: Book review: Ecological Restoration

authors: Clarkson, Bruce D.

subjects: book review

abstract: This article reviews the book “Ecological Restoration”, by Susan M. Galatowitsch.

text: Book review: Ecological Restoration This article reviews the book “Ecological Restoration”, by Susan M. Galatowitsch.

year: 2013

title: Upsetting Geographies: Sacred Spaces of Matata

authors: Brown, Keri Aroha Michelle

subjects: sacred

abstract: My research focuses on the emotional experience of the unearthing of ancestral bones for local Māori of Matata. The coastal town of Matata in the Eastern Bay of Plenty provides a central case study location as it is a town that is facing the pressure of coastal residential development as well the added strain of dealing with the 2005 flood which has compounded issues over local waahi tapu.  Local iwi have continued to actively advocate for the protection of these sites especially with regard to the ongoing discovery of ancestral bones.

Cultural and emotional geographies provide the theoretical framework for this research. This framework has been particularly useful as it encourages reflexive commentary and alternative ways of approaching and thinking about, and understanding knowledge. I have incorporated the research paradigm of kaupapa Māori which complements my theoretical framework by producing a research design that is organised and shaped according to tikanga Māori while (in) advertently critiquing and challenging traditional ways of conducting research. The overall aim is to explore the current issues surrounding the discovery of ancestral bones through korero with local iwi members. It is through their perspectives, stories, beliefs and opinions that provide a better understanding of the meanings attributed to waahi tapu and the influence of certain events such as the 2005 flood. I examine, critically the relationship between power, sacred sites, bones and the body. 

It is from these objectives that I contribute to an area of scholarship that has been largely left out from geographical enquiry. I suggest that the importance of sacredness and spirituality has been relatively overlooked as an influential factor in people's perceptions of the world around them. This thesis is intended to demonstrate the value of indigenous perspectives of bones, the body and sacredness as a way of better understanding some of the complexities that can arise when cross-cultural approaches collide in environmental planning.  

There are three main themes that have emerged from this research. The first theme has to do with competing knowledges. To Māori, the location and knowledge of ancestral bones is culturally important and is in its self sacred, therefore certain tikanga is applied as a means of a protection mechanism. However this ideologically clashes with traditional scientific western approaches which are privileged over other alternative ways of understanding knowledge, in this case Māori knowledge. The second related theme concerns the process of boundary making and cross-cultural ways of perceiving 'sacred' and 'everyday' spaces. To better understand these perspectives involves acknowledging the embodied and emotional experience of wāhi tapu to Māori, and the active role of kaitiaki in the protection and careful management of these culturally important spaces.

text: Upsetting Geographies: Sacred Spaces of Matata My research focuses on the emotional experience of the unearthing of ancestral bones for local Māori of Matata. The coastal town of Matata in the Eastern Bay of Plenty provides a central case study location as it is a town that is facing the pressure of coastal residential development as well the added strain of dealing with the 2005 flood which has compounded issues over local waahi tapu.  Local iwi have continued to actively advocate for the protection of these sites especially with regard to the ongoing discovery of ancestral bones.

Cultural and emotional geographies provide the theoretical framework for this research. This framework has been particularly useful as it encourages reflexive commentary and alternative ways of approaching and thinking about, and understanding knowledge. I have incorporated the research paradigm of kaupapa Māori which complements my theoretical framework by producing a research design that is organised and shaped according to tikanga Māori while (in) advertently critiquing and challenging traditional ways of conducting research. The overall aim is to explore the current issues surrounding the discovery of ancestral bones through korero with local iwi members. It is through their perspectives, stories, beliefs and opinions that provide a better understanding of the meanings attributed to waahi tapu and the influence of certain events such as the 2005 flood. I examine, critically the relationship between power, sacred sites, bones and the body. 

It is from these objectives that I contribute to an area of scholarship that has been largely left out from geographical enquiry. I suggest that the importance of sacredness and spirituality has been relatively overlooked as an influential factor in people's perceptions of the world around them. This thesis is intended to demonstrate the value of indigenous perspectives of bones, the body and sacredness as a way of better understanding some of the complexities that can arise when cross-cultural approaches collide in environmental planning.  

There are three main themes that have emerged from this research. The first theme has to do with competing knowledges. To Māori, the location and knowledge of ancestral bones is culturally important and is in its self sacred, therefore certain tikanga is applied as a means of a protection mechanism. However this ideologically clashes with traditional scientific western approaches which are privileged over other alternative ways of understanding knowledge, in this case Māori knowledge. The second related theme concerns the process of boundary making and cross-cultural ways of perceiving 'sacred' and 'everyday' spaces. To better understand these perspectives involves acknowledging the embodied and emotional experience of wāhi tapu to Māori, and the active role of kaitiaki in the protection and careful management of these culturally important spaces.

year: 2008