Jean-Pierre Blanchet, Alain Royer, François Châteauneuf, Yacine Bouzid, Yann Blanchard, Jean-François Hamel, Jean de Lafontaine, Pierre Gauthier, Norman O'Neill, Ovidiu Pancrati, Louis Garand
The TICFIRE mission concept developed with the support of the Canadian Space Agency aims: 1) to improve
measurements of water-vapour concentration in the low limit, where cold regions are most sensitive and 2) to determine
the contribution of Thin Ice Clouds (TIC) to the energy balance and the role of their microphysical properties on
atmospheric cooling. TICFIRE is a process-oriented mission on a micro-satellite platform dedicated to observe key
parameters of TIC forming in the cold regions of the Poles and globally, in the upper troposphere. It locates cloud top
profiles at the limb and measures at nadir the corresponding upwelling radiance of the atmosphere directly in the thermal
window and in the Far Infrared (FIR) spectrum over cold geographical regions, precisely where most of the atmospheric
thermal cooling takes place. Due to technological limitations, the FIR spectrum (17 to 50 μm) is not regularly monitored
by conventional sensors despite its major importance. This deficiency in key data also impacts operational weather
forecasting. TICFIRE will provide on a global scale a needed contribution in calibrated radiance assimilation near the IR
maximum emission to improve weather forecast. TICFIRE is therefore a science-driven mission with a strong
operational component. The TICFIRE payload consists of two instruments; the main one being a Nadir-looking
multiband radiometer based on uncooled microbolometer technology and covering a large spectral range from 7.9 μm to
50 μm. The secondary one is an imager that performs Limb measurements and provides cloud vertical structure
information. This paper presents the key payload requirements, the conceptual design, and the estimated performance of
the TICFIRE payload. Current technology developments in support to the mission are also presented.
The Platform for the Observation of the Earth and for in-orbit Technology Experiments (POETE) mission concept has
been developed to help overcome the scientific and socio-economic issues associated with forest fires. The proposed
mission is based on a series of two highly autonomous and agile microsatellites, allowing for 3 to 7 visits per day. Each
satellite payload includs a VIS-NIR instrument and a MWIR-TIR instrument. The two instruments combined provide for
6 spectral channels spanning from the visible to the thermal infrared for fire monitoring, retrieval of quantitative fire
parameters (such as effective fire temperature, area and radiative energy release), and land surface temperature
measurement. The MWIR-TIR instrument concept is a pushbroom scanner filter radiometer with on-board radiometric
calibration capabilities. Its all-reflective three-mirror input optics delivers a 400-m GSD at an altitude of 700 km,
relaying the scene signal to detectors based on INO's microbolometer technology for detection in four spectral channels
centered at 3.8 μm, 8.8 μm, 10.5 μm and 12.0 μm. This paper presents an overview of the key mission requirements and
derived sensor level requirements. A description of the conceptual design of the MWIR-TIR payload of POETE is given
along with estimates of key performance parameters.
In August 2007, the engineering model of the Rendezvous Lidar System (RLS) was tested at the Sensor Test Range
Facility that has been developed at NASA Langley Research Center for the calibration and characterization of 3-D
imaging sensors. The three-dimensional test pattern used in this characterization is suitable for an empirical verification
of the resolving capability of a lidar for both mid-range terminal rendezvous and hazard avoidance landing. The results
of the RLS lidar measurements are reported and compared with image frames generated by a lidar simulator with an
Effective Instantaneous Field of View (EIFOV) consistent with the actual scanning time-of-flight lidar specifications.
These full-scale tests demonstrated the resolving capability of the lidar under static testing conditions. In landing
operations, even though the lidar has a very short exposure time on a per-pulse basis, the dynamic motion of a lander
spacecraft with respect to the landing site will cause pulse-to-pulse imaging distortion. MDA, Optech, and NGC
Aerospace have teamed together to resolve this issue using motion compensation (platform stabilization) and motion
correction (platform residual correction) techniques. Platform stabilization permits images with homogenous density to
be generated so that no safe landing sites will be missed; platform residual errors that are not prevented by this
stabilization are then corrected in the measurement data prior to map generation. The results of recent developments in
platform stabilization and motion correction are reported and discussed in the context of total imaging error budget.
Future planetary exploration missions will aim at landing a spacecraft in hazardous regions of a planet, thereby requiring an ability to autonomously avoid surface obstacles and land at a safe site. Landing safety is defined in terms of the local topography-slope relative to gravity and surface roughness-and landing dynamics, requireing an impact velocity lower than a given tolerance. In order to meet these challenges, a LIDAR-based Autonomous Planetary landing System (LAPS) was developed, combining the three-dimensional cartographic capabilities of the LIDAR with autonomous 'intelligent' software for interpreting the data and for guiding the Lander to the safe site. This paper provides an overview of the LAPS ability to detect obstacles, identify a safe site and support the navigation of the Lander to the detected safe site. It also demonstrates the performance of the system using real LIDAR data taken over a physical emulation of a Mars terrain.
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