Fine‐Scale Visualization of Aurora in a Wide Area Using Color Digital Camera Images From the International Space Station
Fine‐Scale Visualization of Aurora in a Wide Area Using Color Digital Camera Images From the International Space Station
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DOI：
10.1029/2019ja027729
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发表时间：
2019-03
期刊：
影响因子：
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通讯作者：
S. Nanjo;Y. Hozumi;K. Hosokawa;R. Kataoka;Y. Miyoshi;S. Oyama;M. Ozaki;K. Shiokawa;S. Kurita
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文献类型：
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作者：
S. Nanjo;Y. Hozumi;K. Hosokawa;R. Kataoka;Y. Miyoshi;S. Oyama;M. Ozaki;K. Shiokawa;S. Kurita
这些极光的全彩照片是用安装在国际空间站（ISS）上的数码单反相机拍摄的。由于这些照片没有准确的时间和地理信息，为了将其作为科学数据使用，有必要校准照片的成像参数（如相机的观察方向和视角）。为此，我们按照Hozumi等人（2016,https://doi.org/10.1186/s40623-016-0532-z）的方法，使用国防气象卫星计划卫星拍摄的城市灯光图像校准成像参数。我们使用校准的成像参数将照片映射到地理坐标系中。为了评估映射的准确性，我们比较了同时从国际空间站和地面拍摄的极光。对比离散极光的空间结构和脉动极光的时间变化，在垂直于相机观测方向的方向上，数据集的时间精度小于0.3 s，空间精度小于5 km。生成的数据集具有宽视场（~ 1,100 × 900 km），其时间分辨率小于1秒。不仅如此，在很短的时间内（10分钟）就可以扫描到大范围（经度3000公里）。因此，这种新的成像能力将使我们能够在更大的范围内捕捉到极光的精细空间结构的演变。
The full‐color photographs of aurora have been taken with digital single‐lens reflex cameras mounted on the International Space Station (ISS). Since these photographs do not have accurate time and geographical information, in order to use them as scientific data, it is necessary to calibrate the imaging parameters (such as looking direction and angle of view of the camera) of the photographs. For this purpose, we calibrated the imaging parameters using a city light image taken from the Defense Meteorological Satellite Program satellite following the method of Hozumi et al. (2016, https://doi.org/10.1186/s40623-016-0532-z). We mapped the photographs onto the geographic coordinate system using the calibrated imaging parameters. To evaluate the accuracy of the mapping, we compared the aurora taken simultaneously from ISS and ground. Comparing the spatial structure of discrete aurora and the temporal variation of pulsating aurora, the accuracy of the data set is less than 0.3 s in time and less than 5 km in space in the direction perpendicular to the looking direction of the camera. The generated data set has a wide field of view ( ∼ 1,100 × 900 km), and their temporal resolution is less than 1 s. Not only that, the field of view can sweep a wide area ( ∼ 3,000 km in longitude) in a short time ( ∼ 10 min). Thus, this new imaging capability will enable us to capture the evolution of fine‐scale spatial structure of aurora in a wide area.