Participative Science and Research at the INRA

En raison de son champ d’activités (agriculture, alimentation, environnement), l’INRA est directement confronté au questionnement actuel sur la place des sciences et de l’innovation dans la société. Dans ce contexte, si les sciences et recherches participatives n’ont pas vocation à devenir un mode de fonctionnement universel, elles peuvent constituer une approche pertinente, notamment pour répondre à des enjeux de recherche correspondant à la complexité du monde actuel. L’article propose des points de repère sur ce que recouvrent les démarches participatives dans le milieu scientifique. Il présente également les objectifs de l’INRA en matière de sciences et recherches participatives, l’intérêt et la diversité des projets participatifs menés à l’Institut, ainsi que certains points de vigilance associés à ces démarches.Due to the scope of its work (agriculture, food, environment), the INRA is directly confronted with current issues about the place of the sciences and of innovation in society. In this context, while the vocation of participative science and research is not to become a universal modality, it can be relevant, in particular to meet the research challenges that arise from the complexity of today’s world. The article offers reference points for the areas covered by participative approaches in scientific environments. It also presents the INRA’s objectives in the area of participative science and research, the relevance and diversity of the participative projects carried out at the Institute and a number of flags to monitor in connection with these approaches

Recherche sur / pour / avec la participation - Webinaire Savoir (Faire) Participer…pour changer: n° 12/15

Savoir (Faire) Participer…pour changerQuelles recherches sur et pour la participation ? Quelles questions scientifiques ? Comment les aborder ? Quel apport de la recherche à la pratique

Recherche sur / pour / avec la participation - Webinaire Savoir (Faire) Participer…pour changer: n° 12/15

Savoir (Faire) Participer…pour changerQuelles recherches sur et pour la participation ? Quelles questions scientifiques ? Comment les aborder ? Quel apport de la recherche à la pratique

Performance of Receiver Autonomous Integrity Monitoring (RAIM) for vertically guided approaches

International audienceReceiver Autonomous Integrity Monitoring (RAIM) is a simple and efficient solution to check the integrity of GNSS in civil aviation applications such as Non Precision Approaches (NPA). In the next ten years, in a multi constellation context implying a large number of satellites and new signals, more demanding phases of flight such as Approach with Vertical guidance (APV) operations could be targeted using RAIM to check GNSS integrity. Considering those expectations, it is needed to precisely determine what are the vertically guided approaches that can be achieved

Sequential RAIM designed to detect combined step ramp pseudo-range errors

International audienceConventional snapshot Receiver Autonomous Integrity Monitoring (RAIM) algorithms, which use a single set of measurements collected simultaneously, have limited performances to check the integrity of GNSS in safetycritical civil aviation applications when vertical guidance requirements are applied. In this context, snapshot and sequential RAIM FDE algorithms based on the constrained Generalized Likelihood Ratio (GLR) test have been proposed. These techniques, described in this paper, are based on a formalized definition of a horizontal or vertical error that must be considered as a positioning failure and consist in computing for each epoch and for each satellite channel a minimal additional pseudo range bias that leads to such situations. Proceeding like this allows partially compensating the lack of availability of conventional methods. As such, sequential technique is particularly attractive. Indeed this algorithm takes into account history of measurements to make its decision and moreover the pseudo range correlation is directly integrated through an autoregressive (AR) model. The purpose of our study is to benefit fully from these improvements by targeting more complex fault profiles. A sequential constrained GLR is designed to detect combined step ramp pseudo range errors. Our goal is to protect ourselves from faults that only depend on two parameters: initial position (amplitude of the step) and speed (rate of the slope) and that tend to lead to a positioning failure within an observation window ?t . A first evaluation of this advanced RAIM performances is presented in this paper. The robustness of this method is assessed for several profiles of additional error through a comparison of detection rates. The impact of the constellation geometry on our RAIM availability targeting at APV (APproach with Vertical guidance) requirements is also studied. The results obtained show that the robustness of the existing techniques has been improved by our method. For a combined constellation GPS + Galileo, this first performance evaluation is quite encouraging, before a complete study on a world wide case

Utilisation des modèles GeneSys-Colza et Mapod-Maïs pour raisonner des stratégies de ségrégation de filières et évaluer la faisabilité de certains seuils de pureté dans différents systèmes de culture et de production

National audienc

GPS/Galileo RAIM performance in presence of multiple pseudorange failures due to interference

International audienceIn a multi constellation context, demanding phases of flight such as APV operations can be targeted using Receiver Autonomous Integrity Monitoring (RAIM) to check GNSS integrity. This is why it is necessary to characterize all failure modes inducing range errors of the order of a few meters. One of these failure modes is radio frequency interference which causes very penalizing errors since they can affect several measurements at the same time. This work focuses on advanced and classical GPS/Galileo RAIM performance degradation evaluation in presence of multiple failures due to interference when stringent phases of flight are targeted. The way the User Equivalent Range Error UERE, especially the receiver noise residual error, is computed is first reminded in this paper. The main unintentional interference sources to be accounted for in the ARNS are then given and their impact is discussed. More particularly an expression of the code tracking error envelope in presence of CW interference is proposed. A complete pseudo range measurements model is given taking into account the interference effect. The issue of integrity monitoring in presence of interference is studied considering two different algorithms: the Sequential Constrained Generalized Likelihood Ratio Test based RAIM and the Snapshot Least Squares Residuals RAIM. The last part of this paper is dedicated to GPS/Galileo RAIM simulations that have been conducted using this proposed model on GPS L1/L5 and Galileo E1/E5b pseudorange measurements under different conditions: nominal ones, with a CW interference with a power within the GPS L1 C/A interference mask or 20dB above this mask. CW were added on two frequencies: the worst Galileo spectrum line and the worst GPS spectrum line. The two integrity monitoring algorithms formerly described have been tested for two modes of flight APV 1 and APV2. The goal of these simulations is not to detect interference, it is to observe RAIM capacity to detect a bias, corresponding to a satellite failure with a probability of occurrence of 10-4 /h, in presence of interference It is seen that there is no impact of CW interference within the interference mask. Both algorithms studied manage to detect dangerous biases with the required probability and their actual performance are not degraded. On the contrary, CW interference with a power 20 dB above the mask has an important effect on pseudo range error variance and can even lead to misleading situation using classical snapshot RAIM. However, in any case, if advanced methods of monitoring integrity are used that is to say measuring the ability of detecting dangerous biases, the user will be protected from hazardous misleading situation