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We present an in situ calibration process to derive the transient behavior of the offsetting fluxgate magnetometer (MGF) instruments on the Cassiope spacecraft. The dynamic behavior of the MGF changed on orbit following a software update. Characterizing the new instrument dynamics during normal spacecraft operations and then removing the transients was confounded by significant magnetic interference from the reaction wheels used to orient the spacecraft. Special operations were performed where data were taken in a safehold mode, with the reaction wheels stopped, following a single-event upset of the spacecraft bus flight computer after transiting the South Atlantic Anomaly. The slow single-axis rotation of the safehold mode was used to characterize the fluxgate's new feedback dynamics. This characterization process was then adapted for routine operation intervals with slow reaction wheel rates to allow the transient behavior to be characterized over long intervals of data spanning a wide range of temperatures. Subtracting these characterized transients from the flight data improves the instrument's noise floor and allows the instrument to accurately track rapidly changing local fields without loss of measurement fidelity. More generally, this characterization process should apply to other situations where the dynamics of an offsetting instrument must be calibrated in situ.

We present the initial scientific results from the CASSIOPE small satellite mission, which was successfully launched on September 29, 2013 into an elliptic polar orbit of 325×1500 km at 81° inclination. The CASSIOPE spacecraft uses the Canadian small satellite bus to carry the Enhanced Polar Outflow Probe (e-POP) scientific (space weather research) payload and the Cascade communications technology demonstration payload into orbit. The e-POP payload is comprised of a suite of eight high-resolution plasma, magnetic field, radio, and optical instruments designed for in-situ observations in the topside polar ionosphere at the highest-possible resolution. The payload utilizes the advanced data storage and telemetry downlink capability of Cascade to meet its large data downlink bandwidth requirements – and to help demonstrate the capabilities of Cascade in the process. We present preliminary results from the first several months of CASSIOPE mission operation, to demonstrate the performance of both payloads, and the scientific capabilities of the e-POP mission in coordination with other observing facilities.

The GIOS program has conducted HF scatter and ionosphere propagation tests to show that a single HF transmitter can illuminate greater than 1000 km of ocean surface and scatter waves to single satellite in low earth orbit. The receiver in orbit samples the HF illuminated area to measure Brag scatter from the ocean with signals that pass through the ionosphere. The Doppler shifts and group delays map to specific points on the ocean surface at each point in the satellite orbit. Using the theory of ocean scatter, both coherent (specular) and incoherent (Bragg) scatter components at HF frequency provides bistatic sampling of global ocean surface. Data based models of the waveheight spectrum have been used in simulations to validate this concept. Experimental tests with the HF transmitter of ROTHR/VA and space based receiver of ePOP/RRI have provided data that were collected in April 2015. Actual interpretation in of the satellite measurements in terms of ocean surface parameters is in progress. A practical GIOS system will require measurements from a spacecraft flying below the ionosphere. For this purpose, the Naval Research Laboratory has designed a satellite called CARINA which will orbit the earth at an altitude of 200 to 250 km for 60 days.

The Solar wind Magnetosphere Ionosphere Link Explorer (SMILE) is a collaborative science mission between ESA and the Chinese Academy of Sciences (CAS). SMILE is a novel self-standing mission to observe the coupling of the solar wind and Earth's magnetosphere via X-Ray imaging of the solar wind -- magnetosphere interaction zones, UV imaging of global auroral distributions and simultaneous in-situ solar wind, magnetosheath plasma and magnetic field measurements. The SMILE mission proposal was submitted by a consortium of European, Chinese and Canadian scientists following a joint call for mission by ESA and CAS. It was formally selected by ESA's Science Programme Committee (SPC) as an element of the ESA Science Program in November 2015, with the goal of a launch at the end of 2021. In order to achieve its scientific objectives, the SMILE payload will comprise four instruments: the Soft X-ray Imager (SXI), which will spectrally map the Earth's magnetopause, magnetosheath and magnetospheric cusps; the UltraViolet Imager (UVI), dedicated to imaging the auroral regions; the Light Ion Analyser (LIA) and the MAGnetometer (MAG), which will establish the solar wind properties simultaneously with the imaging instruments. We report on the status of the mission and payload developments and the findings of a design study carried out in parallel at the concurrent design facilities (CDF) of ESA and CAS in October/November 2015.

The CASSIOPE Enhanced Polar Outflow Probe (e-POP) is a Canadian small-satellite mission dedicated to the study of polar ion outflows and related magnetosphere-ionosphere coupling processes in the topside ionosphere. Scheduled for launch in 2009, it will carry eight scientific instruments, including imaging plasma and neutral particle sensors, magnetometers, dual-frequency GPS receivers, CCD cameras, a radio wave receiver and a beacon transmitter, for in-situ particle, field, and current measurements and auroral imaging and radio measurements. We present an overview of the e-POP mission, its current status and plan of observations and data distribution during the operation phase of the mission.

Viking UV images of the northern hemisphere auroral region were examined during simultaneous substorms and polar arcs. Of 120 substorm events, 43 recorded polar arcs. In all events the substorm and polar arc were identified with the images, and a strict definition of the term polar arc has been applied to rigorously eliminate any ambiguous cases from this study. In addition, simultaneous events of substorms and polar arcs were separated into four cases: dawnside polar arcs before substorm onset, dawnside polar arcs after onset, duskside polar arcs before onset, and duskside polar arcs after onset. Superposition epoch plots of the average polar arc intensity over time with respect to substorm onset were created. Overall, these plots suggest a weak coupling between the polar arc and the substorm mechanisms. In most of the simultaneous cases, little or no motion of the polar arc was measured. This observation, combined with the various intensity minimum determined in the superposition epoch plots, suggests little or no change occurs in the thickness of the plasma sheet as many substorm models predict. Furthermore, magnetic field line mapping frequently indicates magnetic field lines of polar arcs stretch far down the magnetotail (i.e., greater than 50 Earth Radii), while substorms appear to be located within 20 R e . This concept, combined with the theory that the interaction between the polar arcs and substorms is weak, suggests that substorms cannot be a distant magnetotail event, otherwise there would be a stronger interaction between the two.

[1] We investigate the two-dimensional structure of auroral poleward boundary intensifications (PBIs). PBIs are a nightside auroral intensification that has been studied primarily with ground-based meridian scanning photometers (MSPs). They have a signature that in the MSP data, appears as an increase in intensity at or near the magnetic separatrix and is often seen to extend equatorward. They are also associated with fast flows in the tail and are thus important to the dynamics of the plasma sheet. MSP data provide information about the temporal evolution of the aurora in one spatial dimension, in this case roughly along a magnetic meridian. This paper is motivated by a desire to determine the physics of PBIs that is revealed by their two-dimensional structure. To do this, we have identified a number of PBI events in the CANOPUS Rankin Inlet and Gillam MSPs that occurred at times when high-resolution, two-dimensional images of the aurora over the same region were also available. The two-dimensional images used in this study were obtained by the Freja UV imager, from October 1992 to January 1993, and by the CANOPUS Gillam all-sky imager during the winter viewing season of 1996–1997. We find that PBIs, as observed by the MSPs, are either equatorward extending or non-equatorward extending. Equatorward extending PBIs are either north-south aligned structures or east-west arcs propagating mostly equatorward, but we were not able to determine without doubt which type is the most prevalent. We suggest that equatorward extending PBIs may be the auroral footprint of two major modes of energy transfer in the plasma sheet: multiple, narrow, earthward fast-flow channels in the plasma sheet and sequences of azimuthally broad and primarily earthward propagating phase fronts initiating near the separatrix. Nonequatorward extending PBIs are found to mostly be a series of multiple bead-like intensifications along the poleward boundary of the aurora zone. Such PBIs may be evidence for shear instabilities at the separatrix boundary on the flanks of the magnetotail.

The imaging and rapid-scanning ion mass spectrometer (IRM) is part of the Enhanced Polar Outflow Probe (e-POP) instrument suite on the Canadian CASSIOPE small satellite. Designed to measure the composition and detailed velocity distributions of ions in the ∼1–100 eV/q range on a non-spinning spacecraft, the IRM sensor consists of a planar entrance aperture, a pair of electrostatic deflectors, a time-of-flight (TOF) gate, a hemispherical electrostatic analyzer, and a micro-channel plate (MCP) detector. The TOF gate measures the transit time of each detected ion inside the sensor. The hemispherical analyzer disperses incident ions by their energy-per-charge and azimuth in the aperture plane onto the detector. The two electrostatic deflectors may be optionally programmed to step through a sequence of deflector voltages, to deflect ions of different incident elevation out of the aperture plane and energy-per-charge into the sensor aperture for sampling. The position and time of arrival of each detected ion at the detector are measured, to produce an image of 2-dimensional (2D), mass-resolved ion velocity distribution up to 100 times per second, or to construct a composite 3D velocity distribution by combining successive images in a deflector voltage sequence. The measured distributions are then used to investigate ion composition, density, drift velocity and temperature in polar ion outflows and related acceleration and transport processes in the topside ionosphere.

The Suprathermal Electron Imager (SEI) on the Enhanced Polar Outflow Probe (e-POP) experiment uses a microchannel-plate-intensified charge-coupled device (CCD) detector to record two-dimensional, energy-angle images of electron distributions for energies up to 350 eV. Alternatively, the SEI can be biased to measure positive ions at energies that include the ambient ionospheric population (

The Fast Auroral Imager (FAI) consists of two charge-coupled device (CCD) cameras: one to measure the 630 nm emission of atomic oxygen in aurora and enhanced night airglow; and the other to observe the prompt auroral emissions in the 650 to 1100 nm range. High sensitivity is realized through the combination of fast lens systems (f/0.8) and CCDs of high quantum efficiency (>90 % max). The cameras have a common 26 degree field-of-view to provide nighttime images of about 650 km diameter from apogee at 1500 km. The near infrared camera provides up to two images of 0.1 s exposure per second with a spatial resolution of a few km when the camera is pointing in the nadir direction, making it suitable for studies of dynamic auroral phenomena. The 630-nm camera has been designed to provide one image of 0.5 s exposure every 30 seconds. Launch of the satellite occurred on September 29, 2013. Following a description of the instrument, sample auroral images are presented.