Fast Auroral Imager (FAI) for the e-POP Mission

Cogger, L. L.; Howarth, Andrew; Yau, A. W.; White, A.; Enno, G.; Trondsen, T.; Asquin, Don; Gordon, B.; Marchand, Paul; Ng, Danny Siu-Chun; Burley, Greg; Lessard, M.; Sadler, B.

doi:10.1007/s11214-014-0107-x

Cited by 17 publications

(18 citation statements)

References 9 publications

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“…e‐POP carries in total eight scientific instruments, five of which are used in this study: the suprathermal electron imager (SEI) (Knudsen et al, ), the rapid‐scanning ion mass spectrometer (IRM) (Yau et al, ), the magnetic field instrument (MGF) (Wallis et al, ), the radio receiver instrument (RRI) (James et al, ), and the fast auroral imager (FAI) (Cogger et al, ). Figure depicts the placement and orientation of different sensors on the spacecraft.…”

Section: Instrumentation and Datamentioning

confidence: 99%

Low‐Altitude Ion Heating, Downflowing Ions, and BBELF Waves in the Return Current Region

et al. 2018

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Heavy (O+) ion energization and field‐aligned motion in and near the ionosphere are still not well understood. Based on observations from the CAScade, Smallsat and IOnospheric Polar Explorer (CASSIOPE) Enhanced Polar Outflow Probe at altitudes between 325 km and 730 km over 1 year, we present a statistical study (24 events) of ion heating and its relation to field‐aligned ion bulk flow velocity, low‐frequency waves, and field‐aligned currents. The ion temperature and field‐aligned bulk flow velocity are derived from 2‐D ion velocity distribution functions measured by the suprathermal electron imager (SEI) instrument. Consistent ion heating and flow velocity characteristics are observed from both the SEI and the rapid‐scanning ion mass spectrometer instruments. We find that transverse O+ ion heating in the ionosphere can be intense (up to 4.5 eV), confined to very narrow regions (∼2 km across B), is more likely to occur in the downward current region and is associated with broadband extremely low frequency (BBELF) waves. These waves are interpreted as linearly polarized perpendicular to the magnetic field. The amount of ion heating cannot be explained by frictional heating, and the correlation of ion heating with BBELF waves suggests that significant wave‐ion heating is occurring and even dominating at altitudes as low as 350 km, a boundary that is lower than previously reported. Surprisingly, the majority of these heating events (17 out 24) are associated with core ion downflows rather than upflows. This may be explained by a downward pointing electric field in the low‐altitude return current region.

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Section: Instrumentation and Datamentioning

confidence: 99%

Low‐Altitude Ion Heating, Downflowing Ions, and BBELF Waves in the Return Current Region

et al. 2018

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“…Ex-Alta 1 will be launched from the International Space Station via a NanoRacks deployer to an orbit with a nominal altitude of 400 km, an inclination of 51.6°, and an orbital period of 92.6 min. Field-aligned current measurements will also be validated by comparison to auroral signatures from the THEMIS ground-based observatory all-sky imagers in North America [Mende et al, 2009] and to highcadence (1 Hz) infrared auroral imaging from the e-POP Fast Auroral Imager [Cogger et al, 2015]. Once in orbit, down-sampled magnetic measurements from the magnetometer will be validated by comparison to magnetic field models such as International Geomagnetic Reference Field or CHAOS [Finlay et al, 2015] during magnetically quiet geophysical conditions and portions of the orbit.…”

Section: Introductionmentioning

confidence: 99%

A miniature, low‐power scientific fluxgate magnetometer: A stepping‐stone to cube‐satellite constellation missions

et al. 2016

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Difficulty in making low noise magnetic measurements is a significant challenge to the use of cube‐satellite (CubeSat) platforms for scientific constellation class missions to study the magnetosphere. Sufficient resolution is required to resolve three‐dimensional spatiotemporal structures of the magnetic field variations accompanying both waves and current systems of the nonuniform plasmas controlling dynamic magnetosphere‐ionosphere coupling. This paper describes the design, validation, and test of a flight‐ready, miniature, low‐mass, low‐power, and low‐magnetic noise boom‐mounted fluxgate magnetometer for CubeSat applications. The miniature instrument achieves a magnetic noise floor of 150–200 pT/√Hz at 1 Hz, consumes 400 mW of power, has a mass of 121 g (sensor and boom), stows on the hull, and deploys on a 60 cm boom from a three‐unit CubeSat reducing the noise from the onboard reaction wheel to less than 1.5 nT at the sensor. The instrument's capabilities will be demonstrated and validated in space in late 2016 following the launch of the University of Alberta Ex‐Alta 1 CubeSat, part of the QB50 constellation mission. We illustrate the potential scientific returns and utility of using a CubeSats carrying such fluxgate magnetometers to constitute a magnetospheric constellation using example data from the low‐Earth orbit European Space Agency Swarm mission. Swarm data reveal significant changes in the spatiotemporal characteristics of the magnetic fields in the coupled magnetosphere‐ionosphere system, even when the spacecraft are separated by only approximately 10 s along track and approximately 1.4° in longitude.

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“…The satellite is three‐axis stabilized and nominally nadir‐pointing with an orbital velocity of 7–8 km/s. In order to investigate the properties and mechanisms of polar ion outflow, the CASSIOPE satellite carries several scientific instruments: the magnetic field instrument (MGF), the suprathermal electron imager (SEI), the plasma wave receiver (RRI), an auroral imager (FAI) [ Cogger et al , ], a neutral mass spectrometer (NMS), and the rapid‐scanning ion mass spectrometer (IRM) [ Yau et al , ]. Magnetic field data from MGF, and ion measurements from SEI (operated in a special ion mode) and IRM are used for this study.…”

Section: Instrumentationmentioning

confidence: 99%

Strong ambipolar‐driven ion upflow within the cleft ion fountain during low geomagnetic activity

et al. 2016

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We investigate low‐energy (<10 eV) ion upflows (mainly O+) within the cleft ion fountain (CIF) using conjunctions of the Enhanced Polar Outflow Probe (e‐POP) satellite, the DMSP F16 satellite, the SuperDARN radar, and the Resolute Bay Incoherent Scatter Radar North (RISR‐N). The SEI instrument on board e‐POP enables us to derive ion upflow velocities from the 2‐D images of ion distribution functions with a frame rate of 100 images per second, and with a velocity resolution of the order of 25 m/s. We identify three cleft ion fountain events with very intense (>1.6 km/s) ion upflow velocities near 1000 km altitude during quiet geomagnetic activity (Kp < 3). Such large ion upflow velocities have been reported previously at or below 1000 km, but only during active periods. Analysis of the core ion distribution images allows us to demonstrate that the ion temperature within the CIF does not rise by more than 0.3 eV relative to background values, which is consistent with RISR‐N observations in the F region. The presence of soft electron precipitation seen by DMSP and lack of significant ion heating indicate that the ion upflows we observe near 1000 km altitude are primarily driven by ambipolar electric fields. DC field‐aligned currents (FACs) and convection velocity gradients accompany these events. The strongest ion upflows are associated with downward current regions, which is consistent with some (although not all) previously published results. The moderate correlation coefficient (0.51) between upflow velocities and currents implies that FACs serve as indirect energy inputs to the ion upflow process.

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Fast Auroral Imager (FAI) for the e-POP Mission

Cited by 17 publications

References 9 publications

Low‐Altitude Ion Heating, Downflowing Ions, and BBELF Waves in the Return Current Region

Low‐Altitude Ion Heating, Downflowing Ions, and BBELF Waves in the Return Current Region

A miniature, low‐power scientific fluxgate magnetometer: A stepping‐stone to cube‐satellite constellation missions

Strong ambipolar‐driven ion upflow within the cleft ion fountain during low geomagnetic activity

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