title: Understanding and ameliorating non-linear phase and amplitude responses in AMCW Lidar

authors: Godbaz, John Peter

subjects: phase linearity

abstract: Amplitude modulated continuous wave (AMCW) lidar systems commonly suffer from non-linear phase and amplitude responses due to a number of known factors such as aliasing and multipath inteference. In order to produce useful range and intensity information it is necessary to remove these perturbations from the measurements. We review the known causes of non-linearity, namely aliasing, temporal variation in correlation waveform shape and mixed pixels/multipath inteference. We also introduce other sources of non-linearity, including crosstalk, modulation waveform envelope decay and non-circularly symmetric noise statistics, that have been ignored in the literature. An experimental study is conducted to evaluate techniques for mitigation of non-linearity, and it is found that harmonic cancellation provides a significant improvement in phase and amplitude linearity.

text: Understanding and ameliorating non-linear phase and amplitude responses in AMCW Lidar Amplitude modulated continuous wave (AMCW) lidar systems commonly suffer from non-linear phase and amplitude responses due to a number of known factors such as aliasing and multipath inteference. In order to produce useful range and intensity information it is necessary to remove these perturbations from the measurements. We review the known causes of non-linearity, namely aliasing, temporal variation in correlation waveform shape and mixed pixels/multipath inteference. We also introduce other sources of non-linearity, including crosstalk, modulation waveform envelope decay and non-circularly symmetric noise statistics, that have been ignored in the literature. An experimental study is conducted to evaluate techniques for mitigation of non-linearity, and it is found that harmonic cancellation provides a significant improvement in phase and amplitude linearity.

year: 2012

title: The nutrient impacts of forestry

authors: Beets, Peter

abstract: I have been working on New Zealand’s Land Use and Carbon Analysis System (LUCAS) for the Ministry for the Environment to quantify carbon stocks and changes for planted and natural forests. I originally started at Scion when it was called the Forest Research Institute working on tree nutrition. It is relevant for me to discuss this topic now because after we put the carbon models together I was able to come back to tree nutrition. I was amazed to find the papers we published years ago were still in journals and not incorporated into models that we could use for tree nutrition. I suggested to the managers that it was time for me to put away administrative things and managing projects and focus on reading all those publications, not just from Scion, but other agencies too and put them into models.

text: The nutrient impacts of forestry I have been working on New Zealand’s Land Use and Carbon Analysis System (LUCAS) for the Ministry for the Environment to quantify carbon stocks and changes for planted and natural forests. I originally started at Scion when it was called the Forest Research Institute working on tree nutrition. It is relevant for me to discuss this topic now because after we put the carbon models together I was able to come back to tree nutrition. I was amazed to find the papers we published years ago were still in journals and not incorporated into models that we could use for tree nutrition. I suggested to the managers that it was time for me to put away administrative things and managing projects and focus on reading all those publications, not just from Scion, but other agencies too and put them into models.

year: 2017

title: Maori women and dual ethnicity: Non-congruence, “passing” and “real Maori”

authors: Gibson, Kelly

subjects: Maori

abstract: In this study, I wanted to explore the often uncomfortable experience of having dual ethnicity. I did
this through open-ended interviews with nine women, who, like me, were aged between 20 and 30
and who identified as being of both Maori and Pakeha (or other) descent.
While the women all identified as having dual ethnicity, as the interviews progressed it became
clear that many of them had little pride in being of Pakeha descent and identified more strongly
with their Maori heritage. In most instances the way they were identified by other people was
incongruent with how the participants identified themselves. By virtue of having fair skin, many
were able to “pass” as Pakeha. This provided them with certain advantages, notably being exempt
from racist treatment. On the other hand, their appearance often resulted in them being labelled as
not being a “real Maori.” Paradoxically, when they were identified as Maori, others, both Maori
and non-Maori, sometimes expected them to be an expert in all things Maori. For most participants
being a “real” Maori did not rely on looking Maori or on being able to speak Te Reo fluently.
Instead, having whakapapa was considered the most essential element on which to base their Maori
identity.

text: Maori women and dual ethnicity: Non-congruence, “passing” and “real Maori” In this study, I wanted to explore the often uncomfortable experience of having dual ethnicity. I did
this through open-ended interviews with nine women, who, like me, were aged between 20 and 30
and who identified as being of both Maori and Pakeha (or other) descent.
While the women all identified as having dual ethnicity, as the interviews progressed it became
clear that many of them had little pride in being of Pakeha descent and identified more strongly
with their Maori heritage. In most instances the way they were identified by other people was
incongruent with how the participants identified themselves. By virtue of having fair skin, many
were able to “pass” as Pakeha. This provided them with certain advantages, notably being exempt
from racist treatment. On the other hand, their appearance often resulted in them being labelled as
not being a “real Maori.” Paradoxically, when they were identified as Maori, others, both Maori
and non-Maori, sometimes expected them to be an expert in all things Maori. For most participants
being a “real” Maori did not rely on looking Maori or on being able to speak Te Reo fluently.
Instead, having whakapapa was considered the most essential element on which to base their Maori
identity.

year: 1999