Abstract: This paper concerns body attitude (orientation) estimation for free ranging animal. The main idea of the proposed approach combines a quaternion-based nonlinear observer with an Iterated Least Squares Algorithm (ILSA) and exploits measurements from Micro-Electro-Mechanical-System (MEMS) sensors as 3-axis accelerometer, 3-axis magnetometer and 3-axis gyroscope to produce attitude estimates during the entire range of the observed animal's body movements. Moreover, the proposed observer allows estimating the bias in gyroscope which is used to correct the angular velocity measurements in the attitude estimation step. Since, biologists use an index of DBA for evaluating the energy consumption of the moving animal; the resulting estimations are then used to extract the Dynamic Body Acceleration (DBA) of the animal. Note that, this work is necessary in Bio-logging science and allows monitoring aspects of animal's biology (behavior, movement, and physiology) and environments. The performance of the algorithm is theoretically proven and illustrated by an attitude estimation example. Moreover, the efficiency of the proposed approach is shown with a set of experiments through sensor measurements provided by an Inertial Measurement Unit (IMU). We have also included some comparison results with another method already applied in Bio-logging field in order to point out the improvements issued from the proposed approach.

Abstract: This paper compares chemical stratigraphies from snowpits collected at Dome C (East Antarctica) in order to assess site variability in terms of spatial distribution of chemical markers, annual accumulation rate and chemical species persistence in the snow layers. Since Dome C was chosen for deep drilling down to the bedrock in the framework of EPICA (European Project for Ice Coring in Antarctica), to provide 800kyr of climatic and environmental records, evaluating site variability is fundamental for a reliable interpretation of the deep ice core stratigraphies.
For this purpose, 4 snowpits were dug at Dome C (1997/98, 1998/99, 2000/01 and 2005/06 Antarctic Campaigns) and analysed for cations, inorganic anions and methane sulphonate by ion chromatography. Unlike the first three snowpits, the most recent one was analysed directly in situ, allowing to observe that no chemical contamination or loss due to sample storage and transport to Europe occurs for such a sampling.
Accumulation rate variability was revealed to be around 4% in a common time range (1992-1964) for all snowpits. Intra-snowpit chemical variability was definitely higher than inter-snowpit variability, indicating that the variations observed in the chemical stratigraphies from Dome C can be reliably related to effective changes in source and transport mechanisms of the investigated markers more than to site variability.
Post-depositional phenomena affecting chloride, nitrate and methane sulphonate were studied, revealing a logarithmic decay as a function of depth for Cl- and MSA and an exponential one for NO3-. The relative losses were quantified in the 75-80% range for Cl-, 66-83% for MSA and 89-94% for NO3- and were found to stop around 320, 320 and 60-80cm depth, respectively.

Abstract: This paper analyses atmospheric ionizing radiations induced by Galactic and Solar Cosmic Rays (GCR and SCR, respectively) thanks to continuous measurements of neutron spectrum operated in high-altitude stations. Analyses are reinforced using GCR and SCR models, and extensive air shower descriptions
based on nuclear transport simulations. First analyses were focused on neutron fluxes as function of altitude. Secondly, atmospheric ionizing radiation impacts on biological doses during quiet period and extreme solar events are presented. On the basis of the relevant comparisons conducted for ambient dose equivalent
during quiet solar activity, but also for the comic ray variations calculated and recorded on neutron monitor (NM) during Ground Level Enhancement (GLE) event. GLE 5 model was applied to London ↔ New-york flight dose calculations. All of these results show that dose values vary drastically, on the one hand with the route path (latitude, longitude altitude), on the other hand with the phasing of the solar event. Specific case of Antarctica is discussed because it combines both the high altitude and the very low magnetic field. Analyses show that ionizing radiation in Antarctica environment can be a problematic from the point of view of the human dose, which exerts classical recommendations established for public. This highlights the importance of monitoring atmospheric ionizing radiation, more particularly extreme solar events, then to develop semi-empirical and particle transport method for reliable calculation of dose levels.

Abstract: This is an ongoing PhD work 2013-2016 focused on PAIX project and Polar Antarctic Observations of the pulsating stars.