The Mako airborne longwave-infrared hyperspectral sensor is a whiskbroom imager operating in the 7.6-13.2 μm region with 44-nm spectral sampling and <30 mK noise-equivalent differential temperature (NEDT). It has undergone progressive development since its inaugural flights in 2010 and is capable of acquiring 112° swaths with an areal rate of 33 km2 min-1 at 2-m ground sampling distance. The sensor performance envelope allows for a number of operational modes that can be deployed against a variety of acquisition scenarios. Its suitability for environmental remote sensing applications is illustrated with reference to a number of representative case studies drawn from several years of airborne collections within the Los Angeles Basin and beyond.
The Aerospace Corporation’s sensitive Mako thermal infrared imaging spectrometer, which operates between 7.6 and 13.2 microns at a spectral sampling of 44 nm, and flies in a DeHavilland DHC-6 Twin Otter, has undergone significant changes over the past year that have greatly increased its performance. A comprehensive overhaul of its electronics has enabled frame rates up to 3255 Hz and noise reductions bringing it close to background-limited. A replacement diffraction grating whose peak efficiency was tuned to shorter wavelength, coupled with new AR coatings on certain key optics, has improved the performance at the short wavelength end by a factor of 3, resulting in better sensitivity for methane detection, for example. The faster frame rate has expanded the variety of different scan schemes that are possible, including multi-look scans in which even sizeable target areas can be scanned multiple times during a single overpass. Off-nadir scanning to ±56.4° degrees has also been demonstrated, providing an area scan rate of 33 km2/minute for a 2-meter ground sampling distance (GSD) at nadir. The sensor achieves a Noise Equivalent Spectral Radiance (NESR) of better than 0.6 microflicks (μf, 10-6 W/sr/cm2/μm) in each of the 128 spectral channels for a typical airborne dataset in which 4 frames are co-added. An additional improvement is the integration of a new commercial 3D stabilization mount which is significantly better at compensating for aircraft motions and thereby maintains scan performance under quite turbulent flying conditions. The new sensor performance and capabilities are illustrated.
Remote sensing measurements of ammonia emitted by a near-monotypic seabird colony established on an islet in the Salton Sea (Imperial Valley, California) are described. The compact (3 ha) nature of the island affords a constrained environment that provides an ideal case study for validating models of ammonia emission from seabird colonies. Incorporated as part of a coordinated approach to future field campaigns, the techniques demonstrated would provide a means for validation and refinement of current seabird ammonia emission models on a case study basis. This would contribute to an improved understanding of the nitrogen cycle, especially in remote ocean locales.
A new airborne thermal infrared imaging spectrometer, "Mako", with 128 bands in the thermal infrared covering 7.8 to
13.4 microns, has recently completed its engineering flight trials. Results from these flights, which occurred in
September 2010 and included two science flights, are presented. The new sensor flies in a Twin Otter aircraft and
operates in a whiskbroom mode, giving it the ability to scan to ±40° around nadir. The sensor package is supported on a
commercial 3-axis-stabilized mount which greatly reduces aircraft-induced pointing jitter. The internal optics and focal
plane array are operated near liquid helium temperatures, which in conjunction with a fast f/1.25 spectrometer enables
low noise performance despite the sensor's small (0.55 mrad) pixel size and the high frame rate needed to cover large
whisk angles. Besides the large-area-coverage scan mode (20 km2 per minute at 2-meter GSD from 12,500 ft. AGL), the
sensor features a scan mirror pitch capability that enables both a high-sensitivity mode (longer integration times using
frame summing, covering a smaller spatial region) and a multiple-look mode (multiple looks at a smaller region in a
single aircraft overpass, for discriminating plume motion, for example).
In late 2005 the NASA Earth Science Technology Office convened a working group to review decadal-term technology needs for Earth science active optical remote sensing objectives. The outcome from this effort is intended to guide future NASA investments in laser remote sensing technologies. This paper summarizes the working group findings and places them in context with the conclusions of the National Research Council assessment of future Earth science and applications requirements, completed in 2007.
A novel thermal-band imager is proposed for space-based Earth science measurement applications such as rock
identification and volcano monitoring. The instrument, MAGI-L (Mineral and Gas Identifier - LEO), would also enable
detection of gases from natural and anthropogenic sources. Its higher spectral resolution, compared to ASTER-type
sensors, will improve discrimination of rock types, greatly expand the gas-detection capability, and result in more
accurate land-surface temperatures. The optical design for MAGI-L will incorporate a novel compact Dyson
spectrometer. Data from SEBASS have been used to examine the trade-offs between spectral resolution, spectral range,
and instrument sensitivity for the proposed sensor.
In late 2005 the NASA Earth Science Technology Office convened a working group to review decadal-term technology
needs for Earth science active optical remote sensing objectives. The outcome from this effort is intended to guide future
NASA investments in laser remote sensing technologies. This paper summarizes the working group findings and places
them in context with the conclusions of the National Research Council assessment of Earth science needs, completed in
Although laser remote sensing techniques have been applied to a variety of environmental measurement tasks for several decades, it has not been until relatively recently that the promise held by lidar and laser radar has begun to be exploited for global measurements from an Earth-orbiting vantage point. Notwithstanding the successful demonstration of highresolution laser altimetry and cloud/aerosol profiling from orbital platforms in the last decade, full realization of the potential for these techniques to address important Earth science questions awaits the availability of next generation instruments incorporating durable, high-performance laser transmitters and advanced receiver technologies. Some of the most critical, high-impact Earth science measurement applications are enabled by lidar techniques - in some cases uniquely so. This paper describes some of these scenarios and also the philosophy underlying the investment that the US National Aeronautics and Space Administration (NASA) is making in order to pro-actively accelerate technology development in certain key areas that will contribute to our future ability to field advanced laser remote sensing instrumentation in space.
The Multicenter Airborne Coherent Atmospheric Wind Sensor instrument is an airborne coherent Doppler laser radar (Lidar) capable of measuring atmospheric wind fields and aerosol structure. Since the first demonstration flights onboard the NASA DC-8 research aircraft in September 1995, two additional science flights have been completed. Several system upgrades have also bee implemented. In this paper we discuss the system upgrades and present several case studies which demonstrate the various capabilities of the system.
The global winds measurement application of coherent Doppler lidar requires intensive study of the global climatology of atmospheric aerosol backscatter at infrared wavelengths. An airborne backscatter lidar is discussed, which has been developed to measure atmospheric backscatter profiles at CO2 laser wavelengths. The instrument characteristics and representative flight measurement results are presented.