Category: Special Editions
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Calendar
October 2021
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
September 27, 2021
September 28, 2021
September 29, 2021
September 30, 2021
October 1, 2021
October 2, 2021
October 3, 2021
October 4, 2021
2:00 pm: PhD Seminars I
2:00 pm: PhD Seminars I
October 4, 2021
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Talk 1
Speaker
Alesia Herasimenka (McTao)
Title
Impact of optical properties on the controlability of solar sails
Abstract
Solar sails offer a propellant-less solution to achieve interplanetary transfers, planet escapes, and de-orbiting maneuvers by leveraging on solar radiation pressure (SRP). Despite very few solar sail missions were launched, the temptation to use SRP as an inexhaustible source of propulsion attracted the interest of researchers since decades, and several contributions on the guidance and control of solar sails are available. But the question of controllability remains unsolved.
Orbital control with SRP is challenging because the sail can not generate a force toward the direction of the Sun. Therefore, classical approach to study controllability can not be applied. Controllability means that the sail can move around its initial position. Thus, the fundamental question is: can we modify the orbit of the sail in any desirable way? We tackle this question by formulating a convex semi-infinite optimization problem.
The results show that the sail is locally controllable under a minimal condition on its reflectivity, and minimum requirement for solar sail design is formulated. This requirement can be used for solar sail technical design, as well as for defining its life time due to the phenomenon of optical degradation.
Talk 2
Speaker
Jules Mabon (Ayana)
Title
Combining point processes and CNNs for detection in remote sensing
Abstract
In the case of remotely sensed images, detecting small targets such as vehicles is a arduous task when using frameworks developped for natural images (where objects of interest occupy a good portion of the frame). In such a context, when objects are small and their density is high, we use object interaction priors within a point process simulation. The data term of this point process is learned with a neural network, thus avoiding the handcrafting of a specific detection term.
October 5, 2021
October 6, 2021
October 7, 2021
October 8, 2021
October 9, 2021
October 10, 2021
October 11, 2021
October 12, 2021
October 13, 2021
October 14, 2021
October 15, 2021
October 16, 2021
October 17, 2021
October 18, 2021
October 19, 2021
October 20, 2021
October 21, 2021
October 22, 2021
October 23, 2021
October 24, 2021
October 25, 2021
October 26, 2021
October 27, 2021
October 28, 2021
October 29, 2021
October 30, 2021
October 31, 2021
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Calendar
October 2021 Monday Tuesday Wednesday Thursday Friday Saturday Sunday September 27, 2021 September 28, 2021 September 29, 2021 September 30, 2021 October 1, 2021 October 2, 2021 October 3, 2021 October 4, 2021 2:00 pm: PhD Seminars I
2:00 pm: PhD Seminars IOctober 4, 2021 –
Talk 1
Speaker
Alesia Herasimenka (McTao)
Title
Impact of optical properties on the controlability of solar sails
Abstract
Solar sails offer a propellant-less solution to achieve interplanetary transfers, planet escapes, and de-orbiting maneuvers by leveraging on solar radiation pressure (SRP). Despite very few solar sail missions were launched, the temptation to use SRP as an inexhaustible source of propulsion attracted the interest of researchers since decades, and several contributions on the guidance and control of solar sails are available. But the question of controllability remains unsolved.
Orbital control with SRP is challenging because the sail can not generate a force toward the direction of the Sun. Therefore, classical approach to study controllability can not be applied. Controllability means that the sail can move around its initial position. Thus, the fundamental question is: can we modify the orbit of the sail in any desirable way? We tackle this question by formulating a convex semi-infinite optimization problem.
The results show that the sail is locally controllable under a minimal condition on its reflectivity, and minimum requirement for solar sail design is formulated. This requirement can be used for solar sail technical design, as well as for defining its life time due to the phenomenon of optical degradation.Talk 2
Speaker
Jules Mabon (Ayana)
Title
Combining point processes and CNNs for detection in remote sensing
Abstract
In the case of remotely sensed images, detecting small targets such as vehicles is a arduous task when using frameworks developped for natural images (where objects of interest occupy a good portion of the frame). In such a context, when objects are small and their density is high, we use object interaction priors within a point process simulation. The data term of this point process is learned with a neural network, thus avoiding the handcrafting of a specific detection term.
October 5, 2021 October 6, 2021 October 7, 2021 October 8, 2021 October 9, 2021 October 10, 2021 October 11, 2021 October 12, 2021 October 13, 2021 October 14, 2021 October 15, 2021 October 16, 2021 October 17, 2021 October 18, 2021 October 19, 2021 October 20, 2021 October 21, 2021 October 22, 2021 October 23, 2021 October 24, 2021 October 25, 2021 October 26, 2021 October 27, 2021 October 28, 2021 October 29, 2021 October 30, 2021 October 31, 2021
