We provide an overview of the Vector Electric Field Investigation (VEFI) on the Air Force Communi... more We provide an overview of the Vector Electric Field Investigation (VEFI) on the Air Force Communication/Navigation Outage Forecasting System (C/NOFS) satellite, a mission designed to understand, model, and forecast the presence of equatorial ionospheric irregularities. VEFI is a NASA/GSFC instrument funded by the Air Force Research Laboratory whose main objectives are to: 1) investigate the role of the ambient electric fields in initiating nighttime ionospheric density depletions and turbulence; 2) determine the quasi-DC electric fields associated with abrupt, large amplitude, density depletions, and 3) quantify the spectrum of the wave electric fields and plasma densities (irregularities) associated with density depletions typically referred to as equatorial spread-F. The VEFI instrument includes a vector electric field double probe detector, a fixed-bias Langmuir probe operating in the ion saturation regime, a flux-gate magnetometer, an optical lightning detector, and associated e...
Each half of the Dual Electron Spectrometer (DES) of the Fast Plasma Investigation (FPI) on NASA’... more Each half of the Dual Electron Spectrometer (DES) of the Fast Plasma Investigation (FPI) on NASA’s Magnetospheric MultiScale (MMS) mission utilizes a microchannel plate Chevron stack feeding 16 separate detection channels each with a dedicated anode and amplifier/discriminator chip. The desire to detect events on a single channel with a temporal spacing of 100 ns and a fixed dead-time drove our decision to use an amplifier/discriminator with a very fast (GHz class) front end. Since the inherent frequency response of each pulse in the output of the DES microchannel plate system also has frequency components above a GHz, this produced a number of design constraints not normally expected in electronic systems operating at peak speeds of 10 MHz. Additional constraints are imposed by the geometry of the instrument requiring all 16 channels along with each anode and amplifier/discriminator to be packaged in a relatively small space. We developed an electrical model for board level interac...
ABSTRACT The NSF Firefly CubeSat is a 3U mission designed to perform cutting-edge science, as a s... more ABSTRACT The NSF Firefly CubeSat is a 3U mission designed to perform cutting-edge science, as a secondary payload. Firefly will be the first dedicated mission launched to study Terrestrial Gamma ray Flashes (TGFs), their link to lightning, and their effect in producing energetic electrons that may become stably trapped in the inner radiation belt. Firefly demonstrates the capability of small missions such as CubeSat to do important, focused science, with abundant student involvement, and with a minimal budget and available resources. In addition, a related mission called FireStation will be part of the STP-H4 platform on the International Space Station. FireStation relies heavily on existing flight experience from the NSF-funded Firefly CubeSat mission, with some modifications to interface and sensors. This presentation will focus on the Firefly and FireStation mission design, as well as important lessons learned in the development, testing, and design. Future developments in CubeSat-class spacecraft for measurements of energetic radiation will be discussed.
There is a need for multipoint in-situ measurements to address many scientific problems related t... more There is a need for multipoint in-situ measurements to address many scientific problems related to Geospace. In this paper, we outline an efficient and innovative algorithm that allows multiple spacecraft (s/c) to self-localize their position within a cluster. The new technique is based on measurements of the time-of-arrival of transmitted calibration signals that each s/c broadcasts. Among the features of our self-localization protocol, we emphasize: (a) distributed processing - all computations are performed over the entire cluster network, which provides great stability to the algorithm in case of failure or malfunction of some s/c in the cluster; (b) relative localization of spacecrafts' position allows for local computation of physical quantities of interest (such as the electric field, the magnetic field etc), which reduce the communication time with Earth-based computational centers; and (c) the algorithm is robust vs. statistical noise which is inevitably present, and ca...
Electron spectrometers use a variety of techniques to determine where the amplified electron clou... more Electron spectrometers use a variety of techniques to determine where the amplified electron cloud falls onto a collecting surface. One traditional method divides the collecting surface into sectors and uses a single detector for each sector. However, as the angular and spatial resolution increases, so to do the number of detectors. Thus there is an overall increase in power consumption, cost, and weight of the detector system. An alternative approach connects each sector with a delay line and uses a pair of detectors (e.g., one at each end of the chain). To date, this technique has been implemented using Application Specific Integrated Circuits (ASICs) which are expensive to manufacture and have a long lead-time. In this paper, we report on the implementation and testing of a delay line detector using a low-cost Xilinx FPGA. Our technique is scalable to large sector numbers with very little impact on the system cost, mass, or power dissipation. The specifics of both a nine and ten ...
We describe the development, launch into space, and initial results from a prototype wide field-o... more We describe the development, launch into space, and initial results from a prototype wide field-of-view soft X-ray imager that employs lobster-eye optics and targets heliophysics, planetary, and astrophysics science. The sheath transport observer for the redistribution of mass is the first instrument using this type of optics launched into space and provides proof-of-concept for future flight instruments capable of imaging structures such as the terrestrial cusp, the entire dayside magnetosheath from outside the magnetosphere, comets, the Moon, and the solar wind interaction with planetary bodies like Venus and Mars [Kuntz et al., Astrophys. J. (in press)].
ABSTRACT Because of the wide impact of Mr. E. F. Rent's work in engineering, the applied ... more ABSTRACT Because of the wide impact of Mr. E. F. Rent's work in engineering, the applied sciences, and technology, the original memos of Mr. Rent and historically equivalent (HE) applications to today's complex integrated circuitry were published in the IBM Journal of Research and Development in 2005. It has been shown that evaluating existing wirelength distribution models with this HE interpretation of Rent's memos provides improved qualitative agreement with measurements and more accurate estimates of on-chip wirelength requirements for application-specific integrated circuit designs in the POWER4™ microprocessor core. Because of the increasing impact of Rent's work, including research on integration density for future computers and expansion to the fields of post-CMOS devices and bioengineering, this paper presents a review of these contributions and a new mathematical framework that explains the HE interpretation of Rent's memos. This framework provides topological constraints for today's ultralarge-scale integrated circuits, as well as a model that predicts this HE interpretation. The model arises from the underlying topology of the circuitry and interconnectivity of the circuit components. Using this model, predictions of the HE Rent parameters are obtained and show agreement to within $-$5% to $+$12% of the experimental values obtained from published data for the POWER4 microprocessor circuit designs.
We provide an overview of the Vector Electric Field Investigation (VEFI) on the Air Force Communi... more We provide an overview of the Vector Electric Field Investigation (VEFI) on the Air Force Communication/Navigation Outage Forecasting System (C/NOFS) satellite, a mission designed to understand, model, and forecast the presence of equatorial ionospheric irregularities. VEFI is a NASA/GSFC instrument funded by the Air Force Research Laboratory whose main objectives are to: 1) investigate the role of the ambient electric fields in initiating nighttime ionospheric density depletions and turbulence; 2) determine the quasi-DC electric fields associated with abrupt, large amplitude, density depletions, and 3) quantify the spectrum of the wave electric fields and plasma densities (irregularities) associated with density depletions typically referred to as equatorial spread-F. The VEFI instrument includes a vector electric field double probe detector, a fixed-bias Langmuir probe operating in the ion saturation regime, a flux-gate magnetometer, an optical lightning detector, and associated e...
Each half of the Dual Electron Spectrometer (DES) of the Fast Plasma Investigation (FPI) on NASA’... more Each half of the Dual Electron Spectrometer (DES) of the Fast Plasma Investigation (FPI) on NASA’s Magnetospheric MultiScale (MMS) mission utilizes a microchannel plate Chevron stack feeding 16 separate detection channels each with a dedicated anode and amplifier/discriminator chip. The desire to detect events on a single channel with a temporal spacing of 100 ns and a fixed dead-time drove our decision to use an amplifier/discriminator with a very fast (GHz class) front end. Since the inherent frequency response of each pulse in the output of the DES microchannel plate system also has frequency components above a GHz, this produced a number of design constraints not normally expected in electronic systems operating at peak speeds of 10 MHz. Additional constraints are imposed by the geometry of the instrument requiring all 16 channels along with each anode and amplifier/discriminator to be packaged in a relatively small space. We developed an electrical model for board level interac...
ABSTRACT The NSF Firefly CubeSat is a 3U mission designed to perform cutting-edge science, as a s... more ABSTRACT The NSF Firefly CubeSat is a 3U mission designed to perform cutting-edge science, as a secondary payload. Firefly will be the first dedicated mission launched to study Terrestrial Gamma ray Flashes (TGFs), their link to lightning, and their effect in producing energetic electrons that may become stably trapped in the inner radiation belt. Firefly demonstrates the capability of small missions such as CubeSat to do important, focused science, with abundant student involvement, and with a minimal budget and available resources. In addition, a related mission called FireStation will be part of the STP-H4 platform on the International Space Station. FireStation relies heavily on existing flight experience from the NSF-funded Firefly CubeSat mission, with some modifications to interface and sensors. This presentation will focus on the Firefly and FireStation mission design, as well as important lessons learned in the development, testing, and design. Future developments in CubeSat-class spacecraft for measurements of energetic radiation will be discussed.
There is a need for multipoint in-situ measurements to address many scientific problems related t... more There is a need for multipoint in-situ measurements to address many scientific problems related to Geospace. In this paper, we outline an efficient and innovative algorithm that allows multiple spacecraft (s/c) to self-localize their position within a cluster. The new technique is based on measurements of the time-of-arrival of transmitted calibration signals that each s/c broadcasts. Among the features of our self-localization protocol, we emphasize: (a) distributed processing - all computations are performed over the entire cluster network, which provides great stability to the algorithm in case of failure or malfunction of some s/c in the cluster; (b) relative localization of spacecrafts' position allows for local computation of physical quantities of interest (such as the electric field, the magnetic field etc), which reduce the communication time with Earth-based computational centers; and (c) the algorithm is robust vs. statistical noise which is inevitably present, and ca...
Electron spectrometers use a variety of techniques to determine where the amplified electron clou... more Electron spectrometers use a variety of techniques to determine where the amplified electron cloud falls onto a collecting surface. One traditional method divides the collecting surface into sectors and uses a single detector for each sector. However, as the angular and spatial resolution increases, so to do the number of detectors. Thus there is an overall increase in power consumption, cost, and weight of the detector system. An alternative approach connects each sector with a delay line and uses a pair of detectors (e.g., one at each end of the chain). To date, this technique has been implemented using Application Specific Integrated Circuits (ASICs) which are expensive to manufacture and have a long lead-time. In this paper, we report on the implementation and testing of a delay line detector using a low-cost Xilinx FPGA. Our technique is scalable to large sector numbers with very little impact on the system cost, mass, or power dissipation. The specifics of both a nine and ten ...
We describe the development, launch into space, and initial results from a prototype wide field-o... more We describe the development, launch into space, and initial results from a prototype wide field-of-view soft X-ray imager that employs lobster-eye optics and targets heliophysics, planetary, and astrophysics science. The sheath transport observer for the redistribution of mass is the first instrument using this type of optics launched into space and provides proof-of-concept for future flight instruments capable of imaging structures such as the terrestrial cusp, the entire dayside magnetosheath from outside the magnetosphere, comets, the Moon, and the solar wind interaction with planetary bodies like Venus and Mars [Kuntz et al., Astrophys. J. (in press)].
ABSTRACT Because of the wide impact of Mr. E. F. Rent's work in engineering, the applied ... more ABSTRACT Because of the wide impact of Mr. E. F. Rent's work in engineering, the applied sciences, and technology, the original memos of Mr. Rent and historically equivalent (HE) applications to today's complex integrated circuitry were published in the IBM Journal of Research and Development in 2005. It has been shown that evaluating existing wirelength distribution models with this HE interpretation of Rent's memos provides improved qualitative agreement with measurements and more accurate estimates of on-chip wirelength requirements for application-specific integrated circuit designs in the POWER4™ microprocessor core. Because of the increasing impact of Rent's work, including research on integration density for future computers and expansion to the fields of post-CMOS devices and bioengineering, this paper presents a review of these contributions and a new mathematical framework that explains the HE interpretation of Rent's memos. This framework provides topological constraints for today's ultralarge-scale integrated circuits, as well as a model that predicts this HE interpretation. The model arises from the underlying topology of the circuitry and interconnectivity of the circuit components. Using this model, predictions of the HE Rent parameters are obtained and show agreement to within $-$5% to $+$12% of the experimental values obtained from published data for the POWER4 microprocessor circuit designs.
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Papers by Joseph Kujawski