Highly Elliptical Orbits for Arctic observations: Assessment of ionizing radiation

Trichtchenko, Larisa; Nikitina, Lidia; Trishchenko, Alexander P.; Garand, Louis

doi:10.1016/j.asr.2014.09.012

Cited by 15 publications

(19 citation statements)

References 21 publications

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“…By selecting the inclination of the orbit to situate the apogee near the critical inclination of 63.44°N, a single satellite can make quasi‐geostationary observations of the ABZ for a limited time before accelerating toward perigee, where it no longer views the ABZ. With two HEO satellites, continuous GEO‐like viewing is possible (aside from external factors like the available sunlight) with a number of different HEO options with periods typically in the range of 12–24 hr and apogee altitudes that are comparable to GEO (Trishchenko et al, ; Tritchtchenko et al, ).…”

Section: Highly Elliptical Orbits For Remote Sensing Of the Abz (Ray mentioning

confidence: 99%

Space‐Based Observations for Understanding Changes in the Arctic‐Boreal Zone

Duncan

Ott

Abshire

et al. 2020

Reviews of Geophysics

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Observations taken over the last few decades indicate that dramatic changes are occurring in the Arctic‐Boreal Zone (ABZ), which are having significant impacts on ABZ inhabitants, infrastructure, flora and fauna, and economies. While suitable for detecting overall change, the current capability is inadequate for systematic monitoring and for improving process‐based and large‐scale understanding of the integrated components of the ABZ, which includes the cryosphere, biosphere, hydrosphere, and atmosphere. Such knowledge will lead to improvements in Earth system models, enabling more accurate prediction of future changes and development of informed adaptation and mitigation strategies. In this article, we review the strengths and limitations of current space‐based observational capabilities for several important ABZ components and make recommendations for improving upon these current capabilities. We recommend an interdisciplinary and stepwise approach to develop a comprehensive ABZ Observing Network (ABZ‐ON), beginning with an initial focus on observing networks designed to gain process‐based understanding for individual ABZ components and systems that can then serve as the building blocks for a comprehensive ABZ‐ON.

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Section: Highly Elliptical Orbits For Remote Sensing Of the Abz (Ray mentioning

confidence: 99%

Space‐Based Observations for Understanding Changes in the Arctic‐Boreal Zone

Duncan

Ott

Abshire

et al. 2020

Reviews of Geophysics

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“…We modeled it for all considered types of orbit with periods of #24 h using the European Space Agency (ESA) Space Environment Information System (SPENVIS) (Heynderickx et al 2004). The SPENVIS model setup follows that one presented in Trichtchenko et al (2014) and Trishchenko et al (2019) and is briefly summarized below. The radiation models for the trapped protons AP8 and electrons AE8 (Sawyer and Vette 1976;Vette 1991) have been utilized for conditions of a solar maximum for consistency with our previous analysis providing conservative estimates.…”

Section: Space Radiation Environmentmentioning

confidence: 99%

“…The total ionizing dose and its components have been estimated using SPENVIS built-in model ''SHIELDOSE'' (Seltzer 1980) with shielding configuration for the finite aluminum slab and the silicon (Si) as target material. The logarithmic values of ionizing dose have been interpolated to derive shielding thickness for an annual total ionizing dose (TID) value selected equal to 3.33 krad, which corresponds to accumulated TID equal to 50 krad for 15-yr space mission (Emmanuel et al 2014;Trichtchenko et al 2014;Trishchenko et al 2019).…”

Section: Space Radiation Environmentmentioning

confidence: 99%

“…The two-satellite TAP HEO constellation offers an attractive orbital solution with three stable apogees separated by 1208 in latitude. A comprehensive analysis of ionizing space radiation conditions for the HEO systems with orbital periods ranging from 6 to 24 h has been presented in Trichtchenko et al (2014). Based on this analysis, Trishchenko et al (2016) introduced the multipleapogee (MAP) HEO systems, notably with periods of 14 and 15 h, that have advantage of more uniform distribution of viewing conditions over the polar zone, which is beneficial for climate and weather applications.…”

Section: Introductionmentioning

confidence: 99%

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Observing Polar Regions from Space: Comparison between Highly Elliptical Orbit and Medium Earth Orbit Constellations

Trishchenko

Garand

Trichtchenko

2019

Journal of Atmospheric and Oceanic Technology

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Continuous observation of polar regions from space remains an important unsolved technical challenge of great interest for the international meteorological community. This capacity would allow achieving global continuous coverage once combined with the geostationary (GEO) satellite network. From a practical point of view, continuous coverage of polar regions with a small number of spacecraft can be obtained from a constellation of satellites either in highly elliptical orbits (HEO) or in medium Earth orbits (MEO). The study compares HEO and MEO satellite constellations for their capacity to provide continuous imaging of polar regions as function of the viewing zenith angle (VZA) and evaluates the corresponding latitude limits that ensure sufficient overlap with GEO imagery. Earlier studies assumed the latitude boundary of 60° and the VZA range 70°–85° depending on the space mission focus: meteorological purposes or communications. From the detailed analysis of meteorological retrieval requirements, this study suggests that the overlap of the GEO and polar observing systems (HEO or MEO) should occur down to the latitude band 45°–50° with a maximum VZA ranging between 60° and 64°. This coverage requirement can be met with two sets of three-satellite HEO constellations (one for each polar area) or a six-satellite MEO constellation. The 12-h Molniya and 14-, 15-, and 16-h HEO systems have been analyzed and determined to meet these revised requirements. The study demonstrates that the six-satellite 24-h MEO system can provide a suitable solution, which is also beneficial from the point of view of ionizing radiation and image acquisition geometry. Among the HEO systems, the 16-h HEO has some advantages relative to other HEO systems from the point of view of spatial coverage and space radiation.

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“…This is, e.g. the long-term SEU rate for a device with a 4 mm shield thickness on a highly elliptical orbit [29] as computed by European Space Agency's Space Environment Information System).…”

Section: Fault Scenariosmentioning

confidence: 99%

Probabilistic timing analysis of time‐randomised caches with fault detection mechanisms

Chen

Panerati

et al. 2019

IET Computers & Digital Techniques

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In the real-time systems domain, time-randomised caches have been proposed as a way to simplify software timing analysis, i.e. the process of estimating the probabilistic worst case execution time (pWCET) of an application. However, the technology scaling of the cache memory manufacturing process is rendering transient and permanent faults more and more likely. These faults, in turn, affect a system's timing behaviour and the complexity of its analysis. In this study, the authors propose a static probabilistic timing analysis approach for time-randomised caches that is able to account for the presence of faults-and their detection mechanisms-using a state-space modelling technique. Their experiments show that the proposed methodology is capable of providing tight pWCET estimates. In their analysis, the effects on the estimation of safe pWCET bounds of two online mechanisms for the detection and classification of faults, i.e. a rule-based system and dynamic hidden Markov models (D-HMMs), are compared. The experimental results show that different mechanisms can greatly affect safe pWCET margins and that, by using D-HMMs, the pWCET of the system can be improved with respect to rule-based detection.

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Highly Elliptical Orbits for Arctic observations: Assessment of ionizing radiation

Cited by 15 publications

References 21 publications

Space‐Based Observations for Understanding Changes in the Arctic‐Boreal Zone

Space‐Based Observations for Understanding Changes in the Arctic‐Boreal Zone

Observing Polar Regions from Space: Comparison between Highly Elliptical Orbit and Medium Earth Orbit Constellations

Probabilistic timing analysis of time‐randomised caches with fault detection mechanisms

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