Organised by the University of Edinburgh and SPIE, this interdisciplinary meeting will highlight newly operational satellite systems providing new sensors supporting sustainability. Advances in the processing of big satellite data will be presented alongside novel analytics, including those producing actionable sustainability intelligence.
We are currently developing a conceptual design for a future ELT NIR large field of view imager-spectrograph,
SMART-MOS, along with several science cases from which top level instrument requirements are being established.
This project form part of the EU Framework 6 Joint Research Activity on Smart Focal Planes. The instrument will offer
multiobject spectroscopy, which will include the long slit mode, and image over a field of view of 1 to 2 arcmin, with
high multiplexing capability. The use of a simple AO ground layer correction is envisaged but the instrument will not
work at the diffraction limit though. Multi slits are the base line for the field selector, even when multi-IFU type
instrument might be considered at later stage. There are two possible operational concepts for SMART-MOS, each of
which involving different technologies: MOEMS type devices or sliding bars. We describe in this contribution the
science cases and discuss the most relevant requirements which will drive the development. Preliminary optical and
mechanical concepts are also sketched which include details about the most relevant part of the instrument.
Multi-object instruments provide an increasing challenge for pick-off technology (the means by which objects are selected in the focal plane and fed to sub-instruments such as integral field spectrographs). We have developed a technology demonstrator for a new pick-off system. The performance requirements for the demonstrator have been driven by the outline requirements for possible ELT instruments and the science requirements based on an ELT science case. The goals for the pick-off include that the system should capable of positioning upwards of one hundred pick-off mirrors to an accuracy better than 5 microns. Additionally, the system should be able to achieve this for a curved focal surface -- in this instance with a radius of curvature of 2m.
This paper presents the first experimental results from one of the approaches adopted within the Smart Focal Plane project -- that of a Planetary Positioning System. This pick-and place system is so called because it uniquely uses a combination of three rotation stages to place a magnetically mounted pick-off mirror at any position and orientation on the focal surface. A fixed angular offset between the two principal rotation stages ensures that the pick-off mirror is always placed precisely perpendicular to the curved focal plane. The pick-off mirror is gripped and released by a planar micromechanical mechanism which is lowered and raised by a coil-actuated linear stage.
A key instrument for an Extremely Large Telescope (ELT) is likely to be multi-object spectrometer which observes at least 100 discrete sources with diffraction limited spatial resolution and moderate spectral resolution in the wavelength region from 1.0 to 2.5 μm. Such an instrument has been chosen as the principal driver for the Smart Focal Planes technology development project which has brought together 14 companies and institutes in Europe and Australia. An overview of a new ELT instrument concept based upon beam manipulators (including novel 'starbug' miniature robots) is presented; supported by a summary of scientific goals and systems requirements. Progress made on specific support technology studies is also presented, including work on image slicer replication and cryogenic reconfigurable slits.
AEROSPATIALE, prime contractor, presents the main results related to the activities performed in order to demonstrate the feasibility of a coherent 2 micrometers lidar instrument capable of measuring water vapor and wind velocity in the planetary boundary layer, and to determine the main subsystem critical items: selected instrument configuration and associated performances, 2 micrometers laser configuration with phase conjugation, coherent receiver chain architecture, and frequency locking and offsetting architecture. The second phase of this study will be dedicated to breadboard the most critical elements of the instrument at 2 micrometers in order to technologically consolidate the feasibility of such an instrument.
AEROSPATIALE, prime contractor, presents the main results related to the activities performed in order to demonstrate the feasibility of a coherent 2 micrometer lidar instrument capable of measuring water vapor and wind velocity in the planetary boundary layer, and to determine the main subsystem critical items: (1) selected instrument configuration and associated performances, (2) 2 micrometer laser configuration with phase conjugation, (3) coherent receiver chain architecture, (4) frequency locking and offsetting architecture. The second phase of this study will be dedicated to breadboard the most critical elements of the instrument at 2 micrometers in order to technologically consolidate the feasibility of such an instrument.
The European Space Agency program for Development of a CO2 Laser for Spaceborne Doppler Wind Lidar Applications addresses both performance and lifetime aspects. Lifetime issues are of particular importance due to the 109 pulse life requirement for a spaceborne laser operating continuously at 10 Hz for a period of three years. Particularly critical lifetime issues for an e-beam sustained laser have been identified as the electron transmitting metal foil separating the electron gun and the laser, and the gas life. Four areas of study have been undertaken to address the foil and gas lifetime issues: Parametric Study of Gaseous Catalysis to determine the range of operating conditions under which oxidation of CO by high energy electrons can be expected to offset dissociation of CO2, thus eliminating the need for solid catalyst. Extended Sealed Runs to demonstrate long life in a representative laser system of the actual size required. Several runs of 107 pulses, and one run of 6.5 X 107 pulses, have been performed. The Foil Thermal Profile has been monitored using a pyroelectric vidicon camera to determine the maximum temperature reached by different candidate foil materials under representative conditions. High Temperature Foil Fatigue tests of 109 pulses have been carried out to simulate the effect of the laser pressure pulse, by performing fatigue tests on foil materials at high temperature.
The transmitter laser is recognised to be one of the most critical technologies for space-based Doppler windlidar .
We present initial evaluation of the performance of an e-beam sustained device in the 1OJ, 10 Hz class. Lifetime issues
are addressed in a subsidiary paper. We describe the design of the device and the results of a number of characterisation studies:
1) General nonoptical tests of gas circulation and heat exchanger efficiency. 2) Performance optimisation to maximise multimode efficiency as a function of energy loading, main discharge
E/N and gas composition, all tests allowed for optimisation of cavity extraction. 3) Characterisation of the novel plasma anode electron gun with respect to beam uniformity, secondary electron
concentration, and current constancy. 4) Optical characterisation to examine operating wavelength, pulse shape, beam profile in the near and far-field,
output energy and electrical to optical conversion efficiency, and frequency behaviour during the pulse.
The European Space Agency is supporting the development of key technologies for future spaceborne Doppler wind lidar instruments. The focus for this work is the ALADIN (Atmospheric Laser Doppler Instrument) program which is directed towards the establishment of a coherent CO2-laser based lidar system to improve operational meteorology and climate science. Technology support for this program has to date centered on the development of a 10 J class electron-beam sustained CO2 laser. The stringent alignment tolerances necessary for coherent spaceborne lidar systems have been addressed by the manufacture and test of a single-axis lag-angle and image-motion compensator. Receiver related work has to date concentrated on advanced signal processing algorithms. An alternative approach to coherent DWL (Doppler Wind Lidar) that shows promise for the longer term is a 2 micrometers lidar based upon InGaAs detection and the all-solid-state Tm:Ho:Host laser. These technologies, which may also find application within a spaceborne water-vapor DIAL (Differential Absorption Lidar), have been the subject of experimental activities in relation to spectroscopy, cw lasing and heterodyne efficiency. Also under development is incoherent DWL operating in the ultra-violet which, whilst not capable of the ultimate sensitivity of coherent lidar, is attractive for its reduced alignment tolerances and can be considered for climate and atmospheric research.