title: Remote sensing of wetlands in the Lake Whangape catchment, Waikato, New Zealand.

authors: Pathayala Ralalage, Sumedha Kusum Amarasena

subjects: Wetlands

abstract: Wetlands are among the world's most valuable ecosystems. They provide numerous ecological and socio-economic benefits. However, wetlands continue to disappear due to the increasing demand for wetland resources. In New Zealand, more than 90% of the original extent of wetlands has been lost since the mid-eighteenth century. Therefore, legislation has been identified for the protection of wetlands as a matter of national importance.

Geographic Information System (GIS) and Remote Sensing (RS) techniques have proven helpful for mapping and monitoring wetland resources. This study aims to understand how RStechniques can classify wetlands in the Lake Whangape catchment, Waikato. The parameters that can be extracted from available data and their effectiveness in the classification process are also studied. 

Four types of input data are collectively employed in the study. The data types are optical RS data, Synthetic Aperture Radar (SAR) data, a Digital Elevation Model (DEM), and wetland polygons provided by the Waikato Regional Council (WRC). All the steps including, accessing satellite scenes and data processing were performed within Google Earth Engine (GEE) computing platform using JavaScript language. The classification process for this study includes feature extraction, feature selection, model training, classification, and validation. Finally, the accuracy of the classification results is checked visually and statistically. 

The classification was carried out in two stages. In Stage one, open water, wetland, and non-wetland areas are classified (simple classification). The combined wetlands class is separated into marsh and swamp in the second stage (detailed classification). Based on the results, the Topographic Position Index (TPI) is the most influential parameter in identifying wetlands, while the Modified Normalized Water Index (MNDWI) successfully identifies open water. The overall accuracy reached 91% at the simple classification stage. However, the detailed classification results received comparatively low classification accuracies (the overall accuracy is 76%).

text: Remote sensing of wetlands in the Lake Whangape catchment, Waikato, New Zealand. Wetlands are among the world's most valuable ecosystems. They provide numerous ecological and socio-economic benefits. However, wetlands continue to disappear due to the increasing demand for wetland resources. In New Zealand, more than 90% of the original extent of wetlands has been lost since the mid-eighteenth century. Therefore, legislation has been identified for the protection of wetlands as a matter of national importance.

Geographic Information System (GIS) and Remote Sensing (RS) techniques have proven helpful for mapping and monitoring wetland resources. This study aims to understand how RStechniques can classify wetlands in the Lake Whangape catchment, Waikato. The parameters that can be extracted from available data and their effectiveness in the classification process are also studied. 

Four types of input data are collectively employed in the study. The data types are optical RS data, Synthetic Aperture Radar (SAR) data, a Digital Elevation Model (DEM), and wetland polygons provided by the Waikato Regional Council (WRC). All the steps including, accessing satellite scenes and data processing were performed within Google Earth Engine (GEE) computing platform using JavaScript language. The classification process for this study includes feature extraction, feature selection, model training, classification, and validation. Finally, the accuracy of the classification results is checked visually and statistically. 

The classification was carried out in two stages. In Stage one, open water, wetland, and non-wetland areas are classified (simple classification). The combined wetlands class is separated into marsh and swamp in the second stage (detailed classification). Based on the results, the Topographic Position Index (TPI) is the most influential parameter in identifying wetlands, while the Modified Normalized Water Index (MNDWI) successfully identifies open water. The overall accuracy reached 91% at the simple classification stage. However, the detailed classification results received comparatively low classification accuracies (the overall accuracy is 76%).

year: 2021

title: Resolving depth measurement ambiguity with commercially available range imaging cameras

authors: McClure, Shane H.

subjects: range imaging

abstract: Time-of-flight range imaging is typically performed with the amplitude modulated continuous wave method. This involves illuminating a scene with amplitude modulated light. Reflected light from the scene is received by the sensor with the range to the scene encoded as a phase delay of the modulation envelope. Due to the cyclic nature of phase, an ambiguity in the measured range occurs every half wavelength in distance, thereby limiting the maximum useable range of the camera.
This paper proposes a procedure to resolve depth ambiguity using software post processing. First, the range data is processed to segment the scene into separate objects. The average intensity of each object can then be used to determine which pixels are beyond the non-ambiguous range. The results demonstrate that depth ambiguity can be resolved for various scenes using only the available depth and intensity information. This proposed method reduces the sensitivity to objects with very high and very low reflectance, normally a key problem with basic threshold approaches.
This approach is very flexible as it can be used with any range imaging camera. Furthermore, capture time is not extended, keeping the artifacts caused by moving objects at a minimum. This makes it suitable for applications such as robot vision where the camera may be moving during captures.
The key limitation of the method is its inability to distinguish between two overlapping objects that are separated by a distance of exactly one non-ambiguous range. Overall the reliability of this method is higher than the basic threshold approach, but not as high as the multiple frequency method of resolving ambiguity.

text: Resolving depth measurement ambiguity with commercially available range imaging cameras Time-of-flight range imaging is typically performed with the amplitude modulated continuous wave method. This involves illuminating a scene with amplitude modulated light. Reflected light from the scene is received by the sensor with the range to the scene encoded as a phase delay of the modulation envelope. Due to the cyclic nature of phase, an ambiguity in the measured range occurs every half wavelength in distance, thereby limiting the maximum useable range of the camera.
This paper proposes a procedure to resolve depth ambiguity using software post processing. First, the range data is processed to segment the scene into separate objects. The average intensity of each object can then be used to determine which pixels are beyond the non-ambiguous range. The results demonstrate that depth ambiguity can be resolved for various scenes using only the available depth and intensity information. This proposed method reduces the sensitivity to objects with very high and very low reflectance, normally a key problem with basic threshold approaches.
This approach is very flexible as it can be used with any range imaging camera. Furthermore, capture time is not extended, keeping the artifacts caused by moving objects at a minimum. This makes it suitable for applications such as robot vision where the camera may be moving during captures.
The key limitation of the method is its inability to distinguish between two overlapping objects that are separated by a distance of exactly one non-ambiguous range. Overall the reliability of this method is higher than the basic threshold approach, but not as high as the multiple frequency method of resolving ambiguity.

year: 2010

title: Archetypes and the unthought: The projection of the King’s Court in New Zealand television media

authors: Mataira, Kelvin

abstract: This thesis explores archetypal projections of conflict in Television New Zealand’s news and current affairs as an unthought. The television news and current affairs programmes identified in the thesis relate to issues of conflict between the Maori people of New Zealand, and the Government and Crown agencies of New Zealand. The unresolved issues of conflict are manifest in what has become popularly known as the Treaty of Waitangi settlement process.

The thesis is informed by Foucault’s conviction that the unthought is the power that is linked to every mode of knowledge. The thesis argues that knowledge in relation to thought is limited because the knowledge is surrounded by an immense region of shadow. In an ontology based on thought only it is shown how the Shadow and the King’s Court archetypes conceal and prevent human beings from comprehending other discourses.

It is argued that Foucault’s concern with the unthought is reflected in Carl Gustav Jung’s convictions about the collective unconscious. Jung’s theory of the quarternio: thinking, sensing, intuition and feeling that describe the four functions of the mind, inform the theory and the methodology for the thesis. It is proposed that the discursive activities of television media can be understood in relation to Hermes the Greek God of magic, lies and illusion. It is further proposed that the images that are projected from television media can be informed by mythical accounts of Hermes’ behaviour and activity in relation to Zeus, Apollo, Dionysus, and Ares.

In the thesis, the quarternio and the Greek Gods are represented by the archetypes of the King’s Court. The Ruler archetype represents Zeus and Apollo as the thinking function of the mind. The Sage archetype is shown to be located in close proximity to the Ruler. The Warrior archetype represents Dionysus as the sensing function of the mind. The Magician archetype represents Hermes as the intuitive function of the mind. The Fool archetype represents Ares as the feeling function of the mind. The Destroyer archetype as the inferior and rejected contents of the collective unconscious represents the archetypal Shadow that undermines the activities of the King’s Court. 

It is maintained in the thesis that television media projections of the King’s Court are a metaphor of the mind, and in particular of the contents of the collective unconscious. The King’s Court as a mythical and archetypal metaphor invites an inspection of the unthought through the epistemology of image. The thesis furnishes a methodology based on the epistemology of television. Through an analysis of popular contemporary films such as the Star Wars Trilogy that are shown to be heavily invested with archetypal motif, discourses for each of the King’s Court archetypes are presented. Foucault’s notion of the rituals and gestures that constitute the true discourse in a regime of truth informs the definition of discourse in the thesis. Discourse in the thesis is to be understood as verbal and non-verbal modes of communication.

Foucault’s notion of disciplinary power provides a method for analysing television news and current affairs programmes as an order of discourse. Disciplinary power enables an understanding of the power relations in television media as the power that circulates in an inquisition between the examiner and the confessor. The archetypes of the King’s Court are projected through the rituals of inquisition in television media.

In the analysis all of the archetypes of the King’s Court are seen except for the Magician. Television it is argued represents the Magician. The Destroyer, the Ruler the Sage, the Warrior and the Fool on television media are controlled by the Magician. The Magician shows that the Ruler’s discourse reflected through the King’s Court represents the regime of truth. The competing discourse of the Destroyer as archetypal foe is located outside of the King’s Court and in opposition to the Ruler’s discourse. The Ruler’s discourse is Apollonine. The Ruler projects the image of control, peace, reconciliation, rationality, serenity, authority, and wealth. The Sage as the intellectual and the Fool as the archetypal Trickster are shown to actively facilitate the power of the Ruler. The Warrior who is projected as a powerful leader may be alienated from the King’s Court.

text: Archetypes and the unthought: The projection of the King’s Court in New Zealand television media This thesis explores archetypal projections of conflict in Television New Zealand’s news and current affairs as an unthought. The television news and current affairs programmes identified in the thesis relate to issues of conflict between the Maori people of New Zealand, and the Government and Crown agencies of New Zealand. The unresolved issues of conflict are manifest in what has become popularly known as the Treaty of Waitangi settlement process.

The thesis is informed by Foucault’s conviction that the unthought is the power that is linked to every mode of knowledge. The thesis argues that knowledge in relation to thought is limited because the knowledge is surrounded by an immense region of shadow. In an ontology based on thought only it is shown how the Shadow and the King’s Court archetypes conceal and prevent human beings from comprehending other discourses.

It is argued that Foucault’s concern with the unthought is reflected in Carl Gustav Jung’s convictions about the collective unconscious. Jung’s theory of the quarternio: thinking, sensing, intuition and feeling that describe the four functions of the mind, inform the theory and the methodology for the thesis. It is proposed that the discursive activities of television media can be understood in relation to Hermes the Greek God of magic, lies and illusion. It is further proposed that the images that are projected from television media can be informed by mythical accounts of Hermes’ behaviour and activity in relation to Zeus, Apollo, Dionysus, and Ares.

In the thesis, the quarternio and the Greek Gods are represented by the archetypes of the King’s Court. The Ruler archetype represents Zeus and Apollo as the thinking function of the mind. The Sage archetype is shown to be located in close proximity to the Ruler. The Warrior archetype represents Dionysus as the sensing function of the mind. The Magician archetype represents Hermes as the intuitive function of the mind. The Fool archetype represents Ares as the feeling function of the mind. The Destroyer archetype as the inferior and rejected contents of the collective unconscious represents the archetypal Shadow that undermines the activities of the King’s Court. 

It is maintained in the thesis that television media projections of the King’s Court are a metaphor of the mind, and in particular of the contents of the collective unconscious. The King’s Court as a mythical and archetypal metaphor invites an inspection of the unthought through the epistemology of image. The thesis furnishes a methodology based on the epistemology of television. Through an analysis of popular contemporary films such as the Star Wars Trilogy that are shown to be heavily invested with archetypal motif, discourses for each of the King’s Court archetypes are presented. Foucault’s notion of the rituals and gestures that constitute the true discourse in a regime of truth informs the definition of discourse in the thesis. Discourse in the thesis is to be understood as verbal and non-verbal modes of communication.

Foucault’s notion of disciplinary power provides a method for analysing television news and current affairs programmes as an order of discourse. Disciplinary power enables an understanding of the power relations in television media as the power that circulates in an inquisition between the examiner and the confessor. The archetypes of the King’s Court are projected through the rituals of inquisition in television media.

In the analysis all of the archetypes of the King’s Court are seen except for the Magician. Television it is argued represents the Magician. The Destroyer, the Ruler the Sage, the Warrior and the Fool on television media are controlled by the Magician. The Magician shows that the Ruler’s discourse reflected through the King’s Court represents the regime of truth. The competing discourse of the Destroyer as archetypal foe is located outside of the King’s Court and in opposition to the Ruler’s discourse. The Ruler’s discourse is Apollonine. The Ruler projects the image of control, peace, reconciliation, rationality, serenity, authority, and wealth. The Sage as the intellectual and the Fool as the archetypal Trickster are shown to actively facilitate the power of the Ruler. The Warrior who is projected as a powerful leader may be alienated from the King’s Court.

year: 2000