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Pose estimation is critical for mobile robots to fulfill various tasks, such as path following or mapping the environment. This is usually accomplished by simultaneous localization and mapping (SLAM). However, computationally constrained systems, such as planetary rovers, rely on less intensive guidance navigation and control (GNC) solutions generally derived solely from visual odometry (VO), wheel odometry, and the onboard inertial measurement unit. Although providing adequate localization performances, the drift accumulated overtime is not compensated by loop closing capabilities, typical of SLAM. Usually, rovers send surface images to the ground station, and these images are used for multiple purposes, such as scientific and operational planning. The number of images is constrained by the communication bandwidth and power budget. The set of transmitted images can be used as a means to correct the robot’s trajectory in an off-line manner. In this work, a solution is presented to the problem of selecting the optimal set of viewpoints belonging to the planned path from which to capture and transmit images: 1) it guarantees accurate trajectory correction and 2) complies with the maximum number of images that can be transmitted to ground control given the available data budget. To this end, it is proposed: 1) a delocalized/decentralized sensor fusion approach based on pose graph optimization and structure from motion and 2) a strategy to select a minimal set of viewpoints along the trajectory that, given a tentative geometry of the environment and the global path that the rover must follow, minimizes the uncertainty of all the robot poses. Optimal camera viewpoint positions are selected as a function of the planned trajectory, the approximate scene geometry, and the maximum transmittable number of images. The proposed method has been tested on a dataset of stereo-images collected in a representative Martian environment, the ALTEC Mars Terrain Simulator (MTS), with the ExoMars testing rover (ExoTeR—European Space Agency, Paris, France, property). Rover stereo-images ground truth was given with millimetric accuracy by a motion capture (MC) system.

γ-ray astronomy in the energy range from MeV to GeV can provide a unique detection window for γ-ray bursts and other transient sources, fundamental information on particle acceleration mechanisms, MeV-blazar population studies up to z ∼ 4.5, and a full overview of line emission from cosmic-ray interaction. Silicon-based pair tracking telescopes rely on γ-ray conversion into an electron–positron pair and its tracking using a stack of silicon strips. The method presented in this work is based on a Rauch–Tung–Striebel smoother. Its internal Kalman filter enables keeping multiple hypotheses about particle tracks and implementing statistically meaningful measurement selection among hits on different planes of the tracker. The algorithm can be easily configured to work with different tracker geometries and mass models. It can be used for the exploitation of data from past and current γ-ray missions as well as to assess the performances of new pair-tracking telescopes. The proposed method has been validated on Astrorivelatore Gamma a Immagini Leggero data and then used to investigate the performances of both e-ASTROGAM and All-Sky-ASTROGAM telescopes. The algorithm efficiency and its accuracy in estimating both the photon direction and energy were evaluated on γ-ray events simulated at different energies in the range between 30 MeV and 3 GeV. The point-spread function of each tracker was then compared with its angular resolution limit showing both the expected performances of the instrument and the margin of improvement that could be obtained by optimizing the reconstruction method.

Thermo-elastic analyses of the High spatial Resolution Imaging Camera (HRIC), which is mounted on Mercury Planetary Orbiter BepiColombo Integrated Observatory SYStem suit (SIMBIO-SYS) of BepiColombo space mission, are carried out in order to evaluate the effect of thermo-elastic deformations on the optical performance experienced by the camera at the worst thermal scenario of Mercury space environment. In particular, the optical performance is evaluated in terms of the pointing error of the camera and the potential presence of optical aberrations.