We present the current development of the Carbon Balance Observatory (CARBO). CARBO is a wide-swath mapping, low Earth orbit (LEO) new generation of instruments that expands on the ground-breaking CO2 and Solar Induced Fluorescence (SIF) measurements pioneered by the Orbiting Carbon Observatory (OCO-2/3) by adding CH4 and CO detection. The instrument’s spatial coverage is delivered at 2 km by 2 km resolution with a field-of-view of 10° to 15° from LEO for a ~200 km wide swath. It achieves roughly 20x better spatial coverage than the OCO-2 instrument, and 3x better Solar Induced Chlorophyll Fluorescence (SIF) detection sensitivity, in a smaller package. CARBO will measure CO2 at <1.5 ppm, CH4 at <7 ppb, CO at <5 ppb and SIF < 20%. The measurement of CO2/CH4/CO/SIF at these concentrations will significantly increase our ability to disentangle carbon fluxes into their constituent components. CARBO utilizes innovative immersion grating technology and enables high resolving power spectroscopy (roughly 20,000) in a smaller and lighter package that is more cost effective than current space-based CO2 remote sensing instruments. CARBO modules cover 4 different spectral ranges (from 740 nm to 2.3μm), where two channels will be built and field tested. CARBO’s modular architecture reduces implementation risk, accelerates access to space, and extends opportunities to a more diverse set of platforms and launch vehicles. CARBO significantly improves our understanding of the global carbon cycle. Here we discuss an overview of the design elements and focus on the expected radiometric performance of channels 1 (~760 nm) and 2 (~1600 nm).
The Carbon Observatory Instrument Suite, or CARBO, consists of four carbon observing instruments sharing a common instrument bus, yet targeted for a particular wavelength band each with a unique science observation. They are: a) Instrument 1, wavelength centered at 756 nm for oxygen and solar-induced chlorophyll fluorescence (SIF) observations, b) Instrument 2, centered at 1629 nm, for carbon dioxide (CO2) and methane (CH4) observation, c) Instrument 3, centered at 2062 nm for carbon dioxide and d) Instrument 4, centered at 2328 for carbon monoxide (CO) and methane. From low-Earth orbit, these instruments have a field-of-view of 10 to 15 degrees, and a spatial resolution of 2 km square. These instruments have a spectral resolving power ranging from ten to twenty thousand, and can monitor columnaverage dry air mole fraction of carbon dioxide (XCO2) at 1.5 ppm, and methane (XCH4) at 7 ppb. These new instruments will advance the use of immersion grating technology in spectrometer instruments in order to reduce the size of the instrument, while improving performance. These compact, capable instruments are envisioned to be compatible with small satellites, yet modular to be configured to address the particular science questions at hand. Here we report on the current status of the instrument design and fabrication, focusing primarily on Instruments 1 and 2. We will describe the key science and engineering requirements and the instrument performance error budget. We will discuss the optical design with particular emphasis on the immersion grating, and the advantages this new technology affords compared to previous instruments. We will also discuss the status of the focal plane array and the detector electronics and housing. Finally, we report on a new approach – developed during this instrument design process - which enables simultaneous measurement of both orthogonal polarization states (S and P) over the field-of-view and optical bandpass. We believe this polarization sensing capability will enable science observations which were previously limited by instrumental and observational degeneracies. In particular: improved sensitivity to all species, better sensitivity to surface polarization effects, better constraints on aerosol scattering parameters, and superior discrimination of the vertical distribution of gases and aerosols.
The Snow and Water Imaging Spectrometer (SWIS) is a science-grade imaging spectrometer and telescope system suitable for CubeSat applications, spanning a 350-1700 nm spectral range with 5.7 nm sampling, a 10 degree field of view and 0.3 mrad spatial resolution. The system operates at F/1.8, providing high throughput for low-reflectivity water surfaces, while avoiding saturation over bright snow or clouds. The SWIS design utilizes heritage from previously demonstrated instruments on airborne platforms, while advancing the state of the art in compact sensors of this kind in terms of size and spectral coverage. We provide an overview of the preliminary spacecraft configuration design for accommodation in a 6U CubeSat platform.
Real-time evolvable systems are possible with a hardware implementation of Genetic Algorithms (GA). We report the
design of an IP core that implements a general purpose GA engine which has been successfully synthesized and verified
on a Xilinx Virtex II Pro FPGA Device (XC2VP30). The placed and routed IP core has an area utilization of only 13%
and clock speed of 50MHz. The GA core can be customized in terms of the population size, number of generations,
cross-over and mutation rates, and the random number generator seed. The GA engine can be tailored to a given
application by interfacing with the application specific fitness evaluation module as well as the required storage memory
(to store the current and new populations). The core is soft in nature i.e., a gate-level netlist is provided which can be
readily integrated with the user's system. The GA IP core can be readily used in FPGA based platforms for space and
military applications (for e.g., surveillance, target tracking). The main advantages of the IP core are its programmability,
small footprint, and low power consumption. Examples of concept systems in sensing and surveillance domains will be
Proc. SPIE. 6959, Micro (MEMS) and Nanotechnologies for Space, Defense, and Security II
KEYWORDS: Microelectromechanical systems, Human-machine interfaces, Digital signal processing, Resonators, Electrodes, Field programmable gate arrays, Control systems, Gyroscopes, Analog electronics, Digital electronics
Inertial navigation systems based upon optical gyroscopes tend to be expensive, large, power consumptive, and are not
long lived. Micro-Electromechanical Systems (MEMS) based gyros do not have these shortcomings; however, until
recently, the performance of MEMS based gyros had been below navigation grade. Boeing and JPL have been cooperating
since 1997 to develop high performance MEMS gyroscopes for miniature, low power space Inertial Reference
Unit applications. The efforts resulted in demonstration of a Post Resonator Gyroscope (PRG). This experience led to the
more compact Disc Resonator Gyroscope (DRG) for further reduced size and power with potentially increased
performance. Currently, the mass, volume and power of the DRG are dominated by the size of the electronics. This
paper will detail the FPGA based digital electronics architecture and its implementation for the DRG which will allow
reduction of size and power and will increase performance through a reduction in electronics noise. Using the digital
control based on FPGA, we can program and modify in real-time the control loop to adapt to the specificity of each
particular gyro and the change of the mechanical characteristic of the gyro during its life time.
We propose a tuning method for Micro-Electro-Mechanical Systems (MEMS) gyroscopes based on evolutionary
computation that has the capacity to efficiently increase the sensitivity of MEMS gyroscopes through tuning and,
furthermore, to find the optimally tuned configuration for this state of increased sensitivity. We present the results of an
experiment to determine the speed and efficiency of an evolutionary algorithm applied to electrostatic tuning of MEMS
micro gyros. The MEMS gyro used in this experiment is a pyrex post resonator gyro (PRG) in a closed-loop control
system. A measure of the quality of tuning is given by the difference in resonant frequencies, or frequency split, for the
two orthogonal rocking axes. The current implementation of the closed-loop platform is able to measure and attain a
relative stability in the sub-millihertz range, leading to a reduction of the frequency split to less than 100 mHz.