Pub Date : 2023-03-01DOI: 10.5140/jass.2023.40.1.35
Dongwoo Kim, Taejin Chung
Surveillance and reconnaissance intelligence in the space domain will become increasingly important in future battlefield environments. Moreover, to assimilate the military provocations and trends of hostile countries, imagery intelligence of the highest possible resolution is required. There are many methods for improving the resolution of optical satellites when observing the ground, such as designing satellite optical systems with a larger diameter and lowering the operating altitude. In this paper, we propose a method for improving ground observation resolution by using an optical system for a previously designed low orbit satellite and lowering the operating altitude of the satellite. When the altitude of a satellite is reduced in a circular orbit, a large amount of thrust fuel is required to maintain altitude because the satellite’s altitude can decrease rapidly due to atmospheric drag. However, by using the critical inclination, which can fix the position of the perigee in an elliptical orbit to the observation area, the operating altitude of the satellite can be reduced using less fuel compared to a circular orbit. This method makes it possible to obtain a similar observational resolution of a medium-sized satellite with the same weight and volume as a small satellite. In addition, this method has the advantage of reducing development and launch costs to that of a small-sized satellite. As a result, we designed an elliptical orbit. The perigee of the orbit is 300 km, the apogee is 8,366.52 km, and the critical inclination is 116.56°. This orbit remains at its lowest altitude to the Korean peninsula constantly with much less orbit maintenance fuel compared to the 300 km circular orbit.
{"title":"Design of an Elliptical Orbit for High-Resolution Optical Observation at a Very Low\u0000 Altitude over the Korean Peninsula","authors":"Dongwoo Kim, Taejin Chung","doi":"10.5140/jass.2023.40.1.35","DOIUrl":"https://doi.org/10.5140/jass.2023.40.1.35","url":null,"abstract":"Surveillance and reconnaissance intelligence in the space domain will become\u0000 increasingly important in future battlefield environments. Moreover, to assimilate the\u0000 military provocations and trends of hostile countries, imagery intelligence of the\u0000 highest possible resolution is required. There are many methods for improving the\u0000 resolution of optical satellites when observing the ground, such as designing satellite\u0000 optical systems with a larger diameter and lowering the operating altitude. In this\u0000 paper, we propose a method for improving ground observation resolution by using an\u0000 optical system for a previously designed low orbit satellite and lowering the operating\u0000 altitude of the satellite. When the altitude of a satellite is reduced in a circular\u0000 orbit, a large amount of thrust fuel is required to maintain altitude because the\u0000 satellite’s altitude can decrease rapidly due to atmospheric drag. However, by using the\u0000 critical inclination, which can fix the position of the perigee in an elliptical orbit\u0000 to the observation area, the operating altitude of the satellite can be reduced using\u0000 less fuel compared to a circular orbit. This method makes it possible to obtain a\u0000 similar observational resolution of a medium-sized satellite with the same weight and\u0000 volume as a small satellite. In addition, this method has the advantage of reducing\u0000 development and launch costs to that of a small-sized satellite. As a result, we\u0000 designed an elliptical orbit. The perigee of the orbit is 300 km, the apogee is 8,366.52\u0000 km, and the critical inclination is 116.56°. This orbit remains at its lowest altitude\u0000 to the Korean peninsula constantly with much less orbit maintenance fuel compared to the\u0000 300 km circular orbit.","PeriodicalId":44366,"journal":{"name":"Journal of Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87929133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-01DOI: 10.5140/jass.2023.40.1.29
A. Yushchenko, Yeuncheol Jeong, V. Yushchenko, A. Demessinova, K. S. Jeong
An unexplained acceleration on the order of 10–8 cm s–2, which is close to cH, where c is the speed of light and H is the Hubble constant, is detected in gravitationally bound systems of different scales, from the solar system to clusters of galaxies. We found that any test body located inside a fractal structure with fractal dimension D = 2 experiences acceleration of the same order and confirmed the previous work that photons propagating through this structure decrease the frequency owing to gravitational redshift. The acceleration can be directed against the movement of the test body. The fractal distribution of the matter should be at scales of at least hundreds of megaparsecs to a few gigaparsecs for the existence of this acceleration.
在不同尺度的引力束缚系统中，从太阳系到星系团，都能探测到一种无法解释的加速度，其数量级为10-8 cm s-2，接近于cH(其中c是光速，H是哈勃常数)。我们发现任何位于分形维数为D = 2的分形结构内的测试体都经历了相同阶的加速度，并证实了先前的工作，即光子通过该结构传播时由于引力红移而降低了频率。加速度可以与试验体的运动方向相反。物质的分形分布应该至少在几百兆秒差距到几百兆秒差距的尺度上，才能存在这种加速。
{"title":"Constant Acceleration in Fractal Structures with Fractal Dimension D = 2","authors":"A. Yushchenko, Yeuncheol Jeong, V. Yushchenko, A. Demessinova, K. S. Jeong","doi":"10.5140/jass.2023.40.1.29","DOIUrl":"https://doi.org/10.5140/jass.2023.40.1.29","url":null,"abstract":"An unexplained acceleration on the order of 10–8 cm s–2, which is close to cH,\u0000 where c is the speed of light and H is the Hubble constant, is detected in\u0000 gravitationally bound systems of different scales, from the solar system to clusters of\u0000 galaxies. We found that any test body located inside a fractal structure with fractal\u0000 dimension D = 2 experiences acceleration of the same order and confirmed the previous\u0000 work that photons propagating through this structure decrease the frequency owing to\u0000 gravitational redshift. The acceleration can be directed against the movement of the\u0000 test body. The fractal distribution of the matter should be at scales of at least\u0000 hundreds of megaparsecs to a few gigaparsecs for the existence of this acceleration.\u0000","PeriodicalId":44366,"journal":{"name":"Journal of Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85973291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-01DOI: 10.5140/jass.2023.40.1.19
M. Odeh, M. Al-Wardat
We present the results of using small telescopes in the United Arab Emirates (UAE) for observing variable stars and asteroids. Two telescopes, namely, 5” apochromatic refractor and 14” Schmidt-Cassegrain, at Al-Khatim Observatory (M44) were used for the observations. The targets were the three variable stars RR GEM, AG LMi, and DL CMi and the asteroid 22 Kalliope. We found a good consistency between our light curves and published ones for the calibration targets, i.e., the asteroid 22 Kalliope and the variable star RR GEM. According to previous studies, AG LMi has two suggested periods, 16.3 hours and 32.62 hours. Our results clearly confirm the second one, with a period of 32.6175 hours. The star DL CMi has several suggested periods as per previous studies, such as 4.0173 days, 1.9606 days, and 2.0086 days. Our observations confirm the first one, with a period of 4.0159 days. These results demonstrate the effectiveness of using small telescopes for observing variable stars and asteroids. This work provides some recommendations on using small telescopes for such observations.
{"title":"Observation of Three Variable Stars and an Asteroid Using Small Telescopes in the\u0000 United Arab Emirates (UAE)","authors":"M. Odeh, M. Al-Wardat","doi":"10.5140/jass.2023.40.1.19","DOIUrl":"https://doi.org/10.5140/jass.2023.40.1.19","url":null,"abstract":"We present the results of using small telescopes in the United Arab Emirates\u0000 (UAE) for observing variable stars and asteroids. Two telescopes, namely, 5”\u0000 apochromatic refractor and 14” Schmidt-Cassegrain, at Al-Khatim Observatory (M44) were\u0000 used for the observations. The targets were the three variable stars RR GEM, AG LMi, and\u0000 DL CMi and the asteroid 22 Kalliope. We found a good consistency between our light\u0000 curves and published ones for the calibration targets, i.e., the asteroid 22 Kalliope\u0000 and the variable star RR GEM. According to previous studies, AG LMi has two suggested\u0000 periods, 16.3 hours and 32.62 hours. Our results clearly confirm the second one, with a\u0000 period of 32.6175 hours. The star DL CMi has several suggested periods as per previous\u0000 studies, such as 4.0173 days, 1.9606 days, and 2.0086 days. Our observations confirm the\u0000 first one, with a period of 4.0159 days. These results demonstrate the effectiveness of\u0000 using small telescopes for observing variable stars and asteroids. This work provides\u0000 some recommendations on using small telescopes for such observations.","PeriodicalId":44366,"journal":{"name":"Journal of Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91102117","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-01DOI: 10.5140/jass.2023.40.1.11
G. Jee
The ionosphere is one of the key components of the near-Earth’s space environment and has a practical consequence to the human society as a nearest region of the space environment to the Earth. Therefore, it becomes essential to specify and forecast the state of the ionosphere using both the observations and numerical models. In particular, numerical modeling of the ionosphere is a prerequisite not only for better understanding of the physical processes occurring within the ionosphere but also for the specification and forecast of the space weather. There are several approaches for modeling the ionosphere, including data-based empirical modeling, physics-based theoretical modeling and data assimilation modeling. In this review, these three types of the ionospheric model are briefly introduced with recently available models. And among those approaches, fundamental aspects of the physics-based ionospheric model will be described using the basic equations governing the mid-latitude ionosphere. Then a numerical solution of the equations will be discussed with required boundary conditions.
{"title":"Fundamentals of Numerical Modeling of the Mid-latitude Ionosphere","authors":"G. Jee","doi":"10.5140/jass.2023.40.1.11","DOIUrl":"https://doi.org/10.5140/jass.2023.40.1.11","url":null,"abstract":"The ionosphere is one of the key components of the near-Earth’s space environment\u0000 and has a practical consequence to the human society as a nearest region of the space\u0000 environment to the Earth. Therefore, it becomes essential to specify and forecast the\u0000 state of the ionosphere using both the observations and numerical models. In particular,\u0000 numerical modeling of the ionosphere is a prerequisite not only for better understanding\u0000 of the physical processes occurring within the ionosphere but also for the specification\u0000 and forecast of the space weather. There are several approaches for modeling the\u0000 ionosphere, including data-based empirical modeling, physics-based theoretical modeling\u0000 and data assimilation modeling. In this review, these three types of the ionospheric\u0000 model are briefly introduced with recently available models. And among those approaches,\u0000 fundamental aspects of the physics-based ionospheric model will be described using the\u0000 basic equations governing the mid-latitude ionosphere. Then a numerical solution of the\u0000 equations will be discussed with required boundary conditions.","PeriodicalId":44366,"journal":{"name":"Journal of Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84130537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-01DOI: 10.5140/jass.2022.39.4.169
A. Yushchenko, D. Doikov, S. Andrievsky, Yeuncheol Jeong, V. Yushchenko, P. Rittipruk, V. Kovtyukh, A. Demessinova, V. Gopka, A. Raikov, K. S. Jeong
We investigated the chemical composition of the planetary host halo star HD47536 via high-resolution spectral observations recorded using a 1.5 meter Cerro Tololo Inter-American Observatory (CTIO) telescope (Chile). Furthermore, we determined the abundances of 38 chemical elements. Both light and heavy elements were overabundant compared to the iron group elements. The abundance pattern of HD47536 was similar to that of halo-type stars, with an enrichment of heavy elements. We analyzed the relationships between the relative abundances of chemical elements and their second ionization potentials and condensation temperatures. We demonstrated that the interplay of charge-exchange reactions owing to the accretion of interstellar matter and the gas-dust separation mechanism can influence the initial abundances and can be used to qualitatively explain the abundance patterns in the atmosphere of HD47536.
{"title":"The Chemical Composition of HD47536: A Planetary Host Halo Giant with Possible λ\u0000 Bootis Features and Signs of Interstellar Matter Accretion","authors":"A. Yushchenko, D. Doikov, S. Andrievsky, Yeuncheol Jeong, V. Yushchenko, P. Rittipruk, V. Kovtyukh, A. Demessinova, V. Gopka, A. Raikov, K. S. Jeong","doi":"10.5140/jass.2022.39.4.169","DOIUrl":"https://doi.org/10.5140/jass.2022.39.4.169","url":null,"abstract":"We investigated the chemical composition of the planetary host halo star HD47536 via high-resolution spectral observations recorded using a 1.5 meter Cerro Tololo Inter-American Observatory (CTIO) telescope (Chile). Furthermore, we determined the abundances of 38 chemical elements. Both light and heavy elements were overabundant compared to the iron group elements. The abundance pattern of HD47536 was similar to that of halo-type stars, with an enrichment of heavy elements. We analyzed the relationships between the relative abundances of chemical elements and their second ionization potentials and condensation temperatures. We demonstrated that the interplay of charge-exchange reactions owing to the accretion of interstellar matter and the gas-dust separation mechanism can influence the initial abundances and can be used to qualitatively explain the abundance patterns in the atmosphere of HD47536.","PeriodicalId":44366,"journal":{"name":"Journal of Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90425166","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-01DOI: 10.5140/jass.2022.39.4.159
Seok-Min Song, K. Min
Because of the small number of spacecraft available in the Earth’s magnetosphere at any given time, it is not possible to obtain direct measurements of the fundamental quantities, such as the magnetic field and plasma density, with a spatial coverage necessary for studying, global magnetospheric phenomena. In such cases, empirical as well as physics-based models are proven to be extremely valuable. This requires not only having high fidelity and high accuracy models, but also knowing the weakness and strength of such models. In this study, we assess the accuracy of the widely used Tsyganenko magnetic field models, T96, T01, and T04, by comparing the calculated magnetic field with the ones measured in-situ by the GOES satellites during geomagnetically disturbed times. We first set the baseline accuracy of the models from a data-model comparison during the intervals of geomagnetically quiet times. During quiet times, we find that all three models exhibit a systematic error of about 10% in the magnetic field magnitude, while the error in the field vector direction is on average less than 1%. We then assess the model accuracy by a data-model comparison during twelve geomagnetic storm events. We find that the errors in both the magnitude and the direction are well maintained at the quiet-time level throughout the storm phase, except during the main phase of the storms in which the largest error can reach 15% on average, and exceed well over 70% in the worst case. Interestingly, the largest error occurs not at the Dst minimum but 2–3 hours before the minimum. Finally, the T96 model has consistently underperformed compared to the other models, likely due to the lack of computation for the effects of ring current. However, the T96 and T01 models are accurate enough for most of the time except for highly disturbed periods.
{"title":"Analysis of the Tsyganenko Magnetic Field Model Accuracy during Geomagnetic Storm\u0000 Times Using the GOES Data","authors":"Seok-Min Song, K. Min","doi":"10.5140/jass.2022.39.4.159","DOIUrl":"https://doi.org/10.5140/jass.2022.39.4.159","url":null,"abstract":"Because of the small number of spacecraft available in the Earth’s magnetosphere\u0000 at any given time, it is not possible to obtain direct measurements of the fundamental\u0000 quantities, such as the magnetic field and plasma density, with a spatial coverage\u0000 necessary for studying, global magnetospheric phenomena. In such cases, empirical as\u0000 well as physics-based models are proven to be extremely valuable. This requires not only\u0000 having high fidelity and high accuracy models, but also knowing the weakness and\u0000 strength of such models. In this study, we assess the accuracy of the widely used\u0000 Tsyganenko magnetic field models, T96, T01, and T04, by comparing the calculated\u0000 magnetic field with the ones measured in-situ by the GOES satellites during\u0000 geomagnetically disturbed times. We first set the baseline accuracy of the models from a\u0000 data-model comparison during the intervals of geomagnetically quiet times. During quiet\u0000 times, we find that all three models exhibit a systematic error of about 10% in the\u0000 magnetic field magnitude, while the error in the field vector direction is on average\u0000 less than 1%. We then assess the model accuracy by a data-model comparison during twelve\u0000 geomagnetic storm events. We find that the errors in both the magnitude and the\u0000 direction are well maintained at the quiet-time level throughout the storm phase, except\u0000 during the main phase of the storms in which the largest error can reach 15% on average,\u0000 and exceed well over 70% in the worst case. Interestingly, the largest error occurs not\u0000 at the Dst minimum but 2–3 hours before the minimum. Finally, the T96 model has\u0000 consistently underperformed compared to the other models, likely due to the lack of\u0000 computation for the effects of ring current. However, the T96 and T01 models are\u0000 accurate enough for most of the time except for highly disturbed periods.","PeriodicalId":44366,"journal":{"name":"Journal of Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79537922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-01DOI: 10.5140/jass.2022.39.4.127
I. Hong, Yu Yi, Nuri Park
Irregular mare patches (IMPs), recently discovered on the Moon, are eruptions of magma on the lunar surface, and their origins are still in question. While prior studies on IMPs have mainly focused on optical image analysis, in this study, an analysis of the characteristics of minerals is performed exemplary for the first time. Modified Gaussian model (MGM) deconvolution was applied to the infrared spectrum to confirm the properties of the mafic mineral. Mafic minerals were analyzed for 6 olivine-rich (Ol-rich) IMPs out of 91 currently reported, and only 4 of them yielded results of significance. All four sites showed more abundance of Fe than Mg, and manifested a weak relationship with Mg-suite rock. However, a problem was discovered during the MGM application process due to pilot implementation. In order to solve this problem, it is required to adjust the MGM initial condition settings more precisely and to increase the signal to noise ratio of the observation data. Moreover, it is necessary to analyze the mineral properties for all IMPs considering minerals other than Ol and utilize them to deduce the origin of the IMPs.
{"title":"Spectral Deconvolution Analysis of Mafic Mineral in Irregular Mare Patches on the\u0000 Moon","authors":"I. Hong, Yu Yi, Nuri Park","doi":"10.5140/jass.2022.39.4.127","DOIUrl":"https://doi.org/10.5140/jass.2022.39.4.127","url":null,"abstract":"Irregular mare patches (IMPs), recently discovered on the Moon, are eruptions of\u0000 magma on the lunar surface, and their origins are still in question. While prior studies\u0000 on IMPs have mainly focused on optical image analysis, in this study, an analysis of the\u0000 characteristics of minerals is performed exemplary for the first time. Modified Gaussian\u0000 model (MGM) deconvolution was applied to the infrared spectrum to confirm the properties\u0000 of the mafic mineral. Mafic minerals were analyzed for 6 olivine-rich (Ol-rich) IMPs out\u0000 of 91 currently reported, and only 4 of them yielded results of significance. All four\u0000 sites showed more abundance of Fe than Mg, and manifested a weak relationship with\u0000 Mg-suite rock. However, a problem was discovered during the MGM application process due\u0000 to pilot implementation. In order to solve this problem, it is required to adjust the\u0000 MGM initial condition settings more precisely and to increase the signal to noise ratio\u0000 of the observation data. Moreover, it is necessary to analyze the mineral properties for\u0000 all IMPs considering minerals other than Ol and utilize them to deduce the origin of the\u0000 IMPs.","PeriodicalId":44366,"journal":{"name":"Journal of Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90199790","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-01DOI: 10.5140/jass.2022.39.4.145
E. Lee, I. Mann, L. Ozeke
The dynamics of the outer zone radiation belt has received a lot of attention mainly due to the correlation between the occurrence of enhancing relativistic electron flux and spacecraft operation anomalies or even failures (e.g., Baker et al. 1994). Relativistic electron events are often observed during great storms associated with ultra low frequency (ULF) waves. For example, a large buildup of relativistic electrons was observed during the great storm of March 24, 1991 (e.g., Li et al. 1993; Hudson et al. 1995; Mann et al. 2013). However, the dominant processes which accelerate magnetospheric radiation belt electrons to MeV energies are not well understood. In this paper, we present observations of Pc5 ULF waves in the recovery phase of the Bastille day storm of July 16, 2000 and electron and proton flux simultaneously oscillating with the same frequencies as the waves. The mechanism for the observed electron and proton flux modulations is examined using groundbased and satellite observations. During this storm time, multiple packets of discrete frequency Pc5 ULF waves appeared associated with energetic particle flux oscillations. We model the drift paths of electrons and protons to determine if the particles drift through the ULF wave to understand why some particle fluxes are modulated by the ULF waves and others are not. We also analyze the flux oscillations of electrons and protons as a function of energy to determine if the particle modulations are caused by a ULF wave drift resonance or advection of a particle density gradient. We suggest that the energetic electron and proton modulations by Pc5 ULF waves provide further evidence in support of the important role that ULF waves play in outer radiation belt dyanamics during storm times.
外区辐射带动力学之所以受到广泛关注，主要是因为相对论性电子通量增强的发生与航天器运行异常甚至故障之间存在相关性(如Baker et al. 1994)。相对论性电子事件经常在与超低频(ULF)波相关的大风暴中被观察到。例如，在1991年3月24日的大风暴期间观测到大量相对论性电子的聚集(例如，Li et al. 1993;Hudson et al. 1995;Mann et al. 2013)。然而，将磁层辐射带电子加速到MeV能量的主要过程还没有得到很好的理解。本文介绍了在2000年7月16日巴士底日风暴恢复阶段的Pc5 ULF波的观测结果，以及电子和质子通量同时以与波相同的频率振荡。利用地基和卫星观测对观测到的电子和质子通量调制机制进行了检验。在这次风暴期间，多个离散频率Pc5 ULF波包出现与高能粒子通量振荡相关。我们模拟了电子和质子的漂移路径，以确定粒子是否通过极低频波漂移，从而理解为什么一些粒子的通量被极低频波调制，而另一些则没有。我们还分析了电子和质子的通量振荡作为能量的函数，以确定粒子调制是由ULF波漂移共振还是粒子密度梯度的平流引起的。我们认为，Pc5超高频波对高能电子和质子的调制提供了进一步的证据，支持超高频波在风暴期间对外辐射带动力学的重要作用。
{"title":"Energetic Electron and Proton Interactions with Pc5 Ultra Low Frequency (ULF) Waves\u0000 during the Great Geomagnetic Storm of 15–16 July 2000","authors":"E. Lee, I. Mann, L. Ozeke","doi":"10.5140/jass.2022.39.4.145","DOIUrl":"https://doi.org/10.5140/jass.2022.39.4.145","url":null,"abstract":"The dynamics of the outer zone radiation belt has received a lot of attention\u0000 mainly due to the correlation between the occurrence of enhancing relativistic electron\u0000 flux and spacecraft operation anomalies or even failures (e.g., Baker et al. 1994).\u0000 Relativistic electron events are often observed during great storms associated with\u0000 ultra low frequency (ULF) waves. For example, a large buildup of relativistic electrons\u0000 was observed during the great storm of March 24, 1991 (e.g., Li et al. 1993; Hudson et\u0000 al. 1995; Mann et al. 2013). However, the dominant processes which accelerate\u0000 magnetospheric radiation belt electrons to MeV energies are not well understood. In this\u0000 paper, we present observations of Pc5 ULF waves in the recovery phase of the Bastille\u0000 day storm of July 16, 2000 and electron and proton flux simultaneously oscillating with\u0000 the same frequencies as the waves. The mechanism for the observed electron and proton\u0000 flux modulations is examined using groundbased and satellite observations. During this\u0000 storm time, multiple packets of discrete frequency Pc5 ULF waves appeared associated\u0000 with energetic particle flux oscillations. We model the drift paths of electrons and\u0000 protons to determine if the particles drift through the ULF wave to understand why some\u0000 particle fluxes are modulated by the ULF waves and others are not. We also analyze the\u0000 flux oscillations of electrons and protons as a function of energy to determine if the\u0000 particle modulations are caused by a ULF wave drift resonance or advection of a particle\u0000 density gradient. We suggest that the energetic electron and proton modulations by Pc5\u0000 ULF waves provide further evidence in support of the important role that ULF waves play\u0000 in outer radiation belt dyanamics during storm times.","PeriodicalId":44366,"journal":{"name":"Journal of Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87858407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-01DOI: 10.5140/jass.2022.39.4.181
Young-Joo Song, Jonghee Bae, Seung-Su Hong, Jun Bang
Korea Pathfinder Lunar Orbiter (KPLO), also known as Danuri, was successfully launched on 4 Aug. from Cape Canaveral Space Force Station using a Space-X Falcon-9 rocket. Flight dynamics (FD) operational readiness was one of the critical parts to be checked before the flight. To demonstrate FD software’s readiness and enhance the operator’s contingency response capabilities, KPLO FD specialists planned, organized, and conducted four simulations and two rehearsals before the KPLO launch. For the efficiency and integrity of FD simulation and rehearsal, different sets of blind test data were prepared, including the simulated tracking measurements that incorporated dynamical model errors, maneuver execution errors, and other errors associated with a tracking system. This paper presents the simulation and rehearsal results with lessons learned for the KPLO FD operational readiness checkout. As a result, every functionality of FD operation systems is firmly secured based on the operation procedure with an enhancement of contingency operational response capability. After conducting several simulations and rehearsals, KPLO FD specialists were much more confident in the flight teams’ ability to overcome the challenges in a realistic flight and FD software’s reliability in flying the KPLO. Moreover, the results of this work will provide numerous insights to the FD experts willing to prepare deep space flight operations.
{"title":"Korea Pathfinder Lunar Orbiter Flight Dynamics Simulation and Rehearsal Results for\u0000 Its Operational Readiness Checkout","authors":"Young-Joo Song, Jonghee Bae, Seung-Su Hong, Jun Bang","doi":"10.5140/jass.2022.39.4.181","DOIUrl":"https://doi.org/10.5140/jass.2022.39.4.181","url":null,"abstract":"Korea Pathfinder Lunar Orbiter (KPLO), also known as Danuri, was successfully\u0000 launched on 4 Aug. from Cape Canaveral Space Force Station using a Space-X Falcon-9\u0000 rocket. Flight dynamics (FD) operational readiness was one of the critical parts to be\u0000 checked before the flight. To demonstrate FD software’s readiness and enhance the\u0000 operator’s contingency response capabilities, KPLO FD specialists planned, organized,\u0000 and conducted four simulations and two rehearsals before the KPLO launch. For the\u0000 efficiency and integrity of FD simulation and rehearsal, different sets of blind test\u0000 data were prepared, including the simulated tracking measurements that incorporated\u0000 dynamical model errors, maneuver execution errors, and other errors associated with a\u0000 tracking system. This paper presents the simulation and rehearsal results with lessons\u0000 learned for the KPLO FD operational readiness checkout. As a result, every functionality\u0000 of FD operation systems is firmly secured based on the operation procedure with an\u0000 enhancement of contingency operational response capability. After conducting several\u0000 simulations and rehearsals, KPLO FD specialists were much more confident in the flight\u0000 teams’ ability to overcome the challenges in a realistic flight and FD software’s\u0000 reliability in flying the KPLO. Moreover, the results of this work will provide numerous\u0000 insights to the FD experts willing to prepare deep space flight operations.","PeriodicalId":44366,"journal":{"name":"Journal of Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90595244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-01DOI: 10.5140/jass.2022.39.4.141
Nuri Park, I. Hong, Jongil Jung
By providing an environment where energetic particles and micrometeorites can not penetrate, caves on Mars may serve as a human shelter in future Mars explorations. More than 1,000 cave entrance candidates have been detected; however, their physical characteristics that can be utilized in detecting more candidates have not been explored in detail. In this paper, we explore the nighttime temperature of 100 cave entrance candidates and their surrounding areas to investigate 1) the nighttime temperature tendencies relative to their surrounding areas and 2) the extent of these temperature differences. We find that 79% of the cave entrance candidates exhibit higher temperatures than the surrounding areas, and 59% show a temperature difference over 20K, suggesting that the cave entrances may generally show higher temperatures than the surrounding areas during the nighttime.
{"title":"Investigation of the Characteristic Nighttime Temperature of Potential Caves on\u0000 Mars","authors":"Nuri Park, I. Hong, Jongil Jung","doi":"10.5140/jass.2022.39.4.141","DOIUrl":"https://doi.org/10.5140/jass.2022.39.4.141","url":null,"abstract":"By providing an environment where energetic particles and micrometeorites can not\u0000 penetrate, caves on Mars may serve as a human shelter in future Mars explorations. More\u0000 than 1,000 cave entrance candidates have been detected; however, their physical\u0000 characteristics that can be utilized in detecting more candidates have not been explored\u0000 in detail. In this paper, we explore the nighttime temperature of 100 cave entrance\u0000 candidates and their surrounding areas to investigate 1) the nighttime temperature\u0000 tendencies relative to their surrounding areas and 2) the extent of these temperature\u0000 differences. We find that 79% of the cave entrance candidates exhibit higher\u0000 temperatures than the surrounding areas, and 59% show a temperature difference over 20K,\u0000 suggesting that the cave entrances may generally show higher temperatures than the\u0000 surrounding areas during the nighttime.","PeriodicalId":44366,"journal":{"name":"Journal of Astronomy and Space Sciences","volume":null,"pages":null},"PeriodicalIF":0.5,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90539909","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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