Simulation of RSO Images for Space Situation Awareness (SSA) Using Parallel Processing

With the rapid increase in resident space objects (RSO), there is a growing demand for their identification and characterization to advance space simulation awareness (SSA) programs. Various AI-based technologies are proposed and demonstrated around the world to effectively and efficiently identify RSOs from ground and space-based observations; however, there remains a challenge in AI training due to the lack of labeled datasets for accurate RSO detection. In this paper, we present an overview of the starfield simulator to generate a realistic representation of images from space-borne imagers. In particular, we focus on low-resolution images such as those taken with a commercial-grade star tracker that contains various RSO in starfield images. The accuracy and computational efficiency of the simulator are compared to the commercial simulator, namely STK-EOIR to demonstrate the performance of the simulator. In comparing over 1000 images from the Fast Auroral Imager (FAI) onboard CASSIOPE satellite, the current simulator generates both stars and RSOs with approximately the same accuracy (compared to the real images) as STK-EOIR and, an order of magnitude faster in computational speed by leveraging parallel processing methodologies.

Comparisons Between E-region Coherent Scatter and Swarm-E Fast Auroral Imager Measurements

<p>The Ionospheric Continuous-wave E-region Bistatic Experimental Auroral Radar (ICEBEAR) is a VHF coherent scatter radar that makes measurements of the E-region ionosphere with a field of view centered on ≈ 58°N, 106°W.  This overlaps with the Saskatoon SuperDARN radar field of view, providing the opportunity for multi-frequency coherent scatter radar measurements in a similar region.  In conjunction with these coherent scatter radar measurements, the Swarm-E, or e-POP, satellite Fast Auroral Imager (FAI) has been used to make measurements of auroral emissions in the 650-1100 nm wavelength band over the same field of view.  The primary emission species in this wavelength range are N<sub>2</sub>, O<sub>2</sub>, and N<sub>2</sub><sup>+</sup>, which correspond to energetic charged particle precipitation penetrating into the lower altitudes of the ionosphere.  This makes the FAI a great instrument for comparison studies with E-region coherent scatter.  In addition to this, the FAI is able to be slewed to a location allowing for extended conjunction windows between the imager and the coherent scatter radars.  With recent advances in radar hardware and processing the temporal and spatial resolutions of these different instruments are becoming comparable (~ 1 s, 1.5 km), providing an excellent opportunity to study plasma density irregularities in the E-region ionosphere in great detail.  Comparisons between the coherent scatter radar and FAI measurements are presented, providing insights into how E-region plasma density irregularities correspond to the location of auroral emissions at 650-1100 nm wavelengths.</p>

Transpolar Arc Observed by the Wide-Field Auroral Imager Onboard Fengyun Satellite

<p><span lang="EN-US">Transpolar arcs that occur primarily under northward interplanetary magnetic field (IMF) are a class of auroral features in the polar cap region. Many mechanisms have been proposed to interpret the generation of the arcs, including reconnection and sudden change in the IMF. It is now generally accepted that IMF B<sub>Y</sub>component plays a key role in the generation and evolution of the arcs. Here we report an interesting long-lasting and moving transpolar arc observed during a geomagnetically quiet period (Dst<10 nT and AE<50 nT) by the wide-field auroral imager (WAI) onboard the Chinese Fengyun satellite. The WAI is a recently launched imager operated in far ultraviolet wavelength (LBH band in 140-180 nm) in a sun-synchronous orbit with a height of ~840 km. It is shown that the arc was initiated at the poleward auroral boundary on dawnside after the IMF turned to be northward and persisted for more than 5 hours. The arc moved toward the noon-midnight line as the IMF B<sub>Y</sub>component changed its direction and then moved back toward dawnside. An interesting phenomenon was that the arc was accompanied with strong energetic proton (30-80 keV) precipitations with geomagnetic latitude greater than 70° but no significant electron precipitations. However, the origin of these energetic protons is unknown and is worthy study in future.</span></p>

Imaging global auroras in space

China’s initial participation in the global monitoring of auroras for scientific and space weather investigations has been enabled by the successful launch of the Chinese Fengyun-3D satellite, which carries a wide-field auroral imager.