Low altitude descent simulation for autonomous lunar landings

Iain Martin (Lead / Corresponding author), Steve Parkes, Martin Dunstan, Nick Rowell

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Abstract

    Future autonomous lunar landers will require robust guidance and navigation systems to safely descend to target landing sites in challenging terrain. Vision or LIDAR based terrain relative navigation can fulfil this role but require extensive testing and tuning so simulating descent scenarios is vital to develop and prove the algorithms and systems. A variety of descent trajectories have been proposed including a low altitude descent which presents a difficult simulation challenge because of the large region of terrain to be modelled. Digital Elevation Models (DEMs) of the lunar surface obtained from previous missions can be used as a basis for terrain models but their resolution needs to be enhanced with synthetic terrain to simulate the full descent. This paper outlines the surface modelling challenges to simulate a low altitude descent sequence and presents a novel, flexible multi-resolution terrain modelling system that can simulate the resolution range of kilometres to centimetres for a surface lander for a variety of descent trajectories. A large area of the Moon is simulated by obtaining the best available DEMs which are then extended into a multi-resolution model through resolution increase and decrease. Low-resolution regions at the outer edge of the model are created by sub-sampling and increasingly higher resolution regions are defined along the simulated descent trajectory with additional synthetic terrain generated by fractal techniques and by adding crater models in realistic diameter and age distributions. The size, position and resolution jumps of the model regions can be specified to optimize the model resolution for the required descent trajectory. Surface patch regions are defined in both high and low-resolution form in a bi-resolution tree to improve performance and avoid over rending issues. The rendering system can traverse the tree to select the most appropriate resolution patch to render based on the depth to the surface. The terrain models are evaluated by applying a feature tracking algorithm to images from a descent sequence to simulate surface relative navigation.
    Original languageEnglish
    Title of host publication64th International Astronautical Congress
    Subtitle of host publicationFinal Programme
    PublisherInternational Astronautical Federation
    Number of pages9
    Publication statusPublished - 25 Sep 2013
    Event64th International Astronautical Congress - China National Convention Center, Beijing, China
    Duration: 23 Sep 201327 Sep 2013
    http://www.iac2013.org/dct/page/1

    Conference

    Conference64th International Astronautical Congress
    Abbreviated titleIAC 2013
    CountryChina
    CityBeijing
    Period23/09/1327/09/13
    Internet address

    Fingerprint

    Lunar landing
    Trajectories
    Navigation
    Moon
    Navigation systems
    Landing
    Fractals
    Tuning

    Cite this

    Martin, I., Parkes, S., Dunstan, M., & Rowell, N. (2013). Low altitude descent simulation for autonomous lunar landings. In 64th International Astronautical Congress: Final Programme International Astronautical Federation.
    Martin, Iain ; Parkes, Steve ; Dunstan, Martin ; Rowell, Nick. / Low altitude descent simulation for autonomous lunar landings. 64th International Astronautical Congress: Final Programme. International Astronautical Federation, 2013.
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    title = "Low altitude descent simulation for autonomous lunar landings",
    abstract = "Future autonomous lunar landers will require robust guidance and navigation systems to safely descend to target landing sites in challenging terrain. Vision or LIDAR based terrain relative navigation can fulfil this role but require extensive testing and tuning so simulating descent scenarios is vital to develop and prove the algorithms and systems. A variety of descent trajectories have been proposed including a low altitude descent which presents a difficult simulation challenge because of the large region of terrain to be modelled. Digital Elevation Models (DEMs) of the lunar surface obtained from previous missions can be used as a basis for terrain models but their resolution needs to be enhanced with synthetic terrain to simulate the full descent. This paper outlines the surface modelling challenges to simulate a low altitude descent sequence and presents a novel, flexible multi-resolution terrain modelling system that can simulate the resolution range of kilometres to centimetres for a surface lander for a variety of descent trajectories. A large area of the Moon is simulated by obtaining the best available DEMs which are then extended into a multi-resolution model through resolution increase and decrease. Low-resolution regions at the outer edge of the model are created by sub-sampling and increasingly higher resolution regions are defined along the simulated descent trajectory with additional synthetic terrain generated by fractal techniques and by adding crater models in realistic diameter and age distributions. The size, position and resolution jumps of the model regions can be specified to optimize the model resolution for the required descent trajectory. Surface patch regions are defined in both high and low-resolution form in a bi-resolution tree to improve performance and avoid over rending issues. The rendering system can traverse the tree to select the most appropriate resolution patch to render based on the depth to the surface. The terrain models are evaluated by applying a feature tracking algorithm to images from a descent sequence to simulate surface relative navigation.",
    author = "Iain Martin and Steve Parkes and Martin Dunstan and Nick Rowell",
    note = "C1. Astrodynamics Symposium: IAC-13.C1.5.10",
    year = "2013",
    month = "9",
    day = "25",
    language = "English",
    booktitle = "64th International Astronautical Congress",
    publisher = "International Astronautical Federation",

    }

    Martin, I, Parkes, S, Dunstan, M & Rowell, N 2013, Low altitude descent simulation for autonomous lunar landings. in 64th International Astronautical Congress: Final Programme. International Astronautical Federation, 64th International Astronautical Congress, Beijing, China, 23/09/13.

    Low altitude descent simulation for autonomous lunar landings. / Martin, Iain (Lead / Corresponding author); Parkes, Steve; Dunstan, Martin; Rowell, Nick.

    64th International Astronautical Congress: Final Programme. International Astronautical Federation, 2013.

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    TY - GEN

    T1 - Low altitude descent simulation for autonomous lunar landings

    AU - Martin, Iain

    AU - Parkes, Steve

    AU - Dunstan, Martin

    AU - Rowell, Nick

    N1 - C1. Astrodynamics Symposium: IAC-13.C1.5.10

    PY - 2013/9/25

    Y1 - 2013/9/25

    N2 - Future autonomous lunar landers will require robust guidance and navigation systems to safely descend to target landing sites in challenging terrain. Vision or LIDAR based terrain relative navigation can fulfil this role but require extensive testing and tuning so simulating descent scenarios is vital to develop and prove the algorithms and systems. A variety of descent trajectories have been proposed including a low altitude descent which presents a difficult simulation challenge because of the large region of terrain to be modelled. Digital Elevation Models (DEMs) of the lunar surface obtained from previous missions can be used as a basis for terrain models but their resolution needs to be enhanced with synthetic terrain to simulate the full descent. This paper outlines the surface modelling challenges to simulate a low altitude descent sequence and presents a novel, flexible multi-resolution terrain modelling system that can simulate the resolution range of kilometres to centimetres for a surface lander for a variety of descent trajectories. A large area of the Moon is simulated by obtaining the best available DEMs which are then extended into a multi-resolution model through resolution increase and decrease. Low-resolution regions at the outer edge of the model are created by sub-sampling and increasingly higher resolution regions are defined along the simulated descent trajectory with additional synthetic terrain generated by fractal techniques and by adding crater models in realistic diameter and age distributions. The size, position and resolution jumps of the model regions can be specified to optimize the model resolution for the required descent trajectory. Surface patch regions are defined in both high and low-resolution form in a bi-resolution tree to improve performance and avoid over rending issues. The rendering system can traverse the tree to select the most appropriate resolution patch to render based on the depth to the surface. The terrain models are evaluated by applying a feature tracking algorithm to images from a descent sequence to simulate surface relative navigation.

    AB - Future autonomous lunar landers will require robust guidance and navigation systems to safely descend to target landing sites in challenging terrain. Vision or LIDAR based terrain relative navigation can fulfil this role but require extensive testing and tuning so simulating descent scenarios is vital to develop and prove the algorithms and systems. A variety of descent trajectories have been proposed including a low altitude descent which presents a difficult simulation challenge because of the large region of terrain to be modelled. Digital Elevation Models (DEMs) of the lunar surface obtained from previous missions can be used as a basis for terrain models but their resolution needs to be enhanced with synthetic terrain to simulate the full descent. This paper outlines the surface modelling challenges to simulate a low altitude descent sequence and presents a novel, flexible multi-resolution terrain modelling system that can simulate the resolution range of kilometres to centimetres for a surface lander for a variety of descent trajectories. A large area of the Moon is simulated by obtaining the best available DEMs which are then extended into a multi-resolution model through resolution increase and decrease. Low-resolution regions at the outer edge of the model are created by sub-sampling and increasingly higher resolution regions are defined along the simulated descent trajectory with additional synthetic terrain generated by fractal techniques and by adding crater models in realistic diameter and age distributions. The size, position and resolution jumps of the model regions can be specified to optimize the model resolution for the required descent trajectory. Surface patch regions are defined in both high and low-resolution form in a bi-resolution tree to improve performance and avoid over rending issues. The rendering system can traverse the tree to select the most appropriate resolution patch to render based on the depth to the surface. The terrain models are evaluated by applying a feature tracking algorithm to images from a descent sequence to simulate surface relative navigation.

    M3 - Conference contribution

    BT - 64th International Astronautical Congress

    PB - International Astronautical Federation

    ER -

    Martin I, Parkes S, Dunstan M, Rowell N. Low altitude descent simulation for autonomous lunar landings. In 64th International Astronautical Congress: Final Programme. International Astronautical Federation. 2013