6 TEMPORAL AND SPATIO-TEMPORAL SAMPLING PROBLEMS

<p>This study addresses mapping of Argo temperature and salinity profiles onto arbitrary positions using physically advanced statistical information from model fields, and their subsequent parametrization as function of depth. Argo suffers from spatio-temporal sampling problems, and some signals are not well captured, e.g. in the deeper ocean below 2000m, around the boundary currents, in the Arctic or in the shelf/coastal regions which are not frequently visited by floats. Mapping of Argo data into sparsely sampled areas would greatly benefit from additional physical information of coherent T/S behavior in form of covariance functions. Outputs from global general ocean circulation model FESOM1.4 provide covariance information for least squares collocation and also complement the spatially undersampled Argo data in high latitudes and in deep ocean. Additionally, model covariances are used to identify areas of strong correlation with interpolation points, so that only Argo measurements inside these areas are included in the mapping procedure. Parametrization of T/S profiles is performed with b-splines where the choice of knot locations is a trade-off between accuracy and overfitting. Proposed methodology is tested in South Atlantic, but can be extended to other regions.</p>

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6 Temporal and Spatio-Temporal Sampling Problems

Journal of the International Commission on Radiation Units and Measurements ◽

10.1093/jicru_ndl011 ◽

2006 ◽

Vol 6 (1) ◽

pp. 65-76

Author(s):

F. W. Whicker ◽

K. Bunzl ◽

P. Dixon ◽

E. M. Scott ◽

S. C. Sheppard ◽

...

Keyword(s):

Temporal Sampling ◽

Spatio Temporal ◽

Sampling Problems

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Spatio-temporal sampling rates and energy efficiency in wireless sensor networks

IEEE INFOCOM 2004 ◽

10.1109/infcom.2004.1354584 ◽

2004 ◽

Cited By ~ 15

Author(s):

S. Bandyopadhyay ◽

E.J. Coyle

Keyword(s):

Energy Efficiency ◽

Wireless Sensor Networks ◽

Sensor Networks ◽

Wireless Sensor ◽

Temporal Sampling ◽

Spatio Temporal

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Cross-validation of IASI/MetOp derived tropospheric δD with TES and ground-based FTIR observations

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-7-11087-2014 ◽

2014 ◽

Vol 7 (11) ◽

pp. 11087-11135

Author(s):

J.-L. Lacour ◽

L. Clarisse ◽

J. Worden ◽

M. Schneider ◽

S. Barthlott ◽

...

Keyword(s):

Near Infrared ◽

Cross Validation ◽

Atmospheric Composition ◽

Free Troposphere ◽

Temporal Sampling ◽

Atmospheric Sounding ◽

Spatio Temporal ◽

Isotopic Variations ◽

Level Of Agreement ◽

Good Agreement

Abstract. The Infrared Atmospheric Sounding Interferometer (IASI) flying on-board MetOpA and MetOpB is able to capture fine isotopic variations of the HDO to H2O ratio (δD) in the troposphere. Such observations at the high spatio temporal resolution of the sounder are of great interest to improve our understanding of the mechanisms controlling humidity in the troposphere. In this study we aim to empirically assess the validity of our error estimation previously evaluated theoretically. To achieve this, we compare IASI δD retrieved profiles with other available profiles of δD, from the TES infrared sounder onboard AURA and from three ground-based FTIR stations produced within the MUSICA project: the NDACC (Network for the Detection of Atmospheric Composition Change) sites Kiruna and Izana, and the TCCON site Karlsruhe, which in addition to near-infrared TCCON spectra also records mid-infrared spectra. We describe the achievable level of agreement between the different retrievals and show that these theoretical errors are in good agreement with empirical differences. The comparisons are made at different locations from tropical to Arctic latitudes, above sea and above land. Generally IASI and TES are similarly sensitive to δD in the free troposphere which allows to compare their measurements directly. At tropical latitudes where IASI's sensitivity is lower than that of TES, we show that the agreement improves when taking into account the sensitivity of IASI in the TES retrieval. For the comparison IASI-FTIR only direct comparisons are performed because of similar sensitivities. We identify a quasi negligible bias in the free troposphere (−3‰) between IASI retrieved δD with the TES one, which are bias corrected, but an important with the ground-based FTIR reaching −47‰. We also suggest that model-satellite observations comparisons could be optimized with IASI thanks to its high spatial and temporal sampling.

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Eye Movement and Pupil Measures: A Review

Frontiers in Computer Science ◽

10.3389/fcomp.2021.733531 ◽

2022 ◽

Vol 3 ◽

Author(s):

Bhanuka Mahanama ◽

Yasith Jayawardana ◽

Sundararaman Rengarajan ◽

Gavindya Jayawardena ◽

Leanne Chukoskie ◽

...

Keyword(s):

Pattern Recognition ◽

Eye Movements ◽

Eye Movement ◽

Motor Coordination ◽

Complex Interaction ◽

Prior Work ◽

Research Directions ◽

Temporal Sampling ◽

Prior Literature ◽

Spatio Temporal

Our subjective visual experiences involve complex interaction between our eyes, our brain, and the surrounding world. It gives us the sense of sight, color, stereopsis, distance, pattern recognition, motor coordination, and more. The increasing ubiquity of gaze-aware technology brings with it the ability to track gaze and pupil measures with varying degrees of fidelity. With this in mind, a review that considers the various gaze measures becomes increasingly relevant, especially considering our ability to make sense of these signals given different spatio-temporal sampling capacities. In this paper, we selectively review prior work on eye movements and pupil measures. We first describe the main oculomotor events studied in the literature, and their characteristics exploited by different measures. Next, we review various eye movement and pupil measures from prior literature. Finally, we discuss our observations based on applications of these measures, the benefits and practical challenges involving these measures, and our recommendations on future eye-tracking research directions.

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