Bow shock crossing list at Mercury (from MESSENGER magnetic field data)

Version 2 (latest): This file contains a list of bow shock crossings at Mercury, identified from magnetic field data of the MESSENGER mission with 1 second resolution (not aberrated), (https://pds-ppi.igpp.ucla.edu/). For a pre-selection of intervals containing bow shock crossings, we use the list of Philpott (2020): "MESSENGER bowshock and magnetopause crossings", https://doi.org/10.5683/SP2/1U6FEO. There, the first and last crossings of the inbound/outbound orbit segments are listed (boundary numbers 1 and 2 for inbound, 7 and 8 for outbound segments). For the bow shock identification, an automatic detection algorithm is applied to these intervals, extended by 45 seconds in either direction. The algorithm calculates running averages and variances of the magnetic field magnitude within adjacent 15 second intervals, separated by two seconds (gap interval). Whenever the ratio between the average magnetic fields exceed a threshold (default: 1.4), a bow shock crossing is selected. Should there be more than one ratio maximum within 10 seconds, then only the maximum is selected that corresponds to the minimal sum of the variances within the adjacent intervals. Crossings are classified with respect to detection quality depending on the ratios of the average magnetic fields and the corresponding variances. Details can be found in the algorithm script that is published alongside this file. Columns of the list file: ['time', 'orbit_number', 'x_mso_km', 'y_mso_km', 'z_mso_km', 'jump_ratio', 'indicator'] 'time': date and time in YYYY-MM-DD HH:mm:SS'orbit_number': orbit number (MESSENGER Mission)'x_mso_km': position (x-coordinate) in MSO coordinate system in km, not aberrated'y_mso_km': position (y-coordinate) in MSO coordinate system in km, not aberrated'z_mso_km': position (z-coordinate) in MSO coordinate system in km, not aberrated'in/out': inbound or outbound segment of the orbit (apoherm towards periherm or periherm towards apoherm)'jump_ratio': ratio of the average magnetic fields before and after selected crossings'indicator': 1, 2 or 3 (1: very clear crossings, high quality, 2: clear crossings, good quality, 3: unclear crossings, poor quality) For further analysis it is recommended to only use the crossings with the indicators 1 and 2.The uncertainty in the determination of the times is +/- 2 seconds. Number of analyzed orbits: 3982Number of total crossings found: 13502Number of crossings with indicator 1 (very clear crossings, best quality): 1765Number of crossings with indicator 2 (clear crossings, good quality): 5027Number of crossings with indicator 3 (unclear crossings, poor quality): 6710 Version 1: This file contains a list of bow shock crossings at Mercury, identified from magnetic field data of the MESSENGER mission with 1 second resolution (not aberrated), (https://pds-ppi.igpp.ucla.edu/). For a pre-selection of intervals containing bow shock crossings, we use the list of Philpott (2020): "MESSENGER bowshock and magnetopause crossings", https://doi.org/10.5683/SP2/1U6FEO. There, the first and last crossings of the inbound/outbound orbit segments are listed (boundary numbers 1 and 2 for inbound, 7 and 8 for outbound segments). For the bow shock identification, an automatic detection algorithm is applied to these intervals, extended by 15 seconds in either direction. The algorithm calculates running averages and variances of the magnetic field magnitude within adjacent 15 second intervals, separated by two seconds (gap interval). Whenever the ratio between the average magnetic fields exceed a threshold (default: 1.4), a bow shock crossing is selected. Should there be more than one ratio maximum within 10 seconds, then only the maximum is selected that corresponds to the minimal sum of the variances within the adjacent intervals. Crossings are classified with respect to detection quality depending on the ratios of the average magnetic fields and the corresponding variances. Details can be found in the algorithm script that is published alongside this file. Columns of the list file: ['time', 'orbit_number', 'x_mso_km', 'y_mso_km', 'z_mso_km', 'in/out', 'jump_ratio', 'indicator'] 'time': date and time in YYYY-MM-DD HH:mm:SS'orbit_number': orbit number (MESSENGER Mission)'x_mso_km': position (x-coordinate) in MSO coordinate system in km, not aberrated'y_mso_km': position (y-coordinate) in MSO coordinate system in km, not aberrated'z_mso_km': position (z-coordinate) in MSO coordinate system in km, not aberrated'in/out': inbound or outbound segment of the orbit (apoherm towards periherm or periherm towards apoherm)'jump_ratio': ratio of the average magnetic fields before and after selected crossings'indicator': 1, 2 or 3 (1: very clear crossings, high quality, 2: clear crossings, good quality, 3: unclear crossings, poor quality) For further analysis it is recommended to only use the crossings with the indicators 1 and 2.The uncertainty in the determination of the times is +/- 2 seconds. Number of analyzed orbits: 3982Number of total crossings found: 65666Number of crossings with indicator 1 (very clear crossings, best quality): 4291Number of crossings with indicator 2 (clear crossings, good quality): 16652Number of crossings with indicator 3 (unclear crossings, poor quality): 44723版本2（最新版）： 本文件收录了水星弓激波（bow shock）穿越事件列表，这些事件基于分辨率为1秒的信使号（MESSENGER）任务磁场数据（未像差校正）识别得到，数据来源：https://pds-ppi.igpp.ucla.edu/。 为预选包含弓激波穿越事件的时段，我们采用了Philpott（2020）发布的列表《信使号弓激波与磁层顶穿越事件》（https://doi.org/10.5683/SP2/1U6FEO）。该列表收录了入轨/出轨段的首次与末次穿越事件（入轨段的边界编号为1和2，出轨段为7和8）。针对弓激波识别，我们对上述时段向两侧各延伸45秒后应用自动检测算法。 该算法对相邻15秒时段内的磁场强度计算滑动平均与方差，两个时段间隔2秒（间隙时段）。当前后平均磁场的比值超过阈值（默认值为1.4）时，即判定为一次弓激波穿越。若10秒内存在多个比值峰值，则仅选取对应相邻时段方差和最小的那个峰值。穿越事件将根据平均磁场比值与对应方差进行检测质量分级。详细信息可参见随本文件一同发布的算法脚本。 列表文件的列字段如下：['time', 'orbit_number', 'x_mso_km', 'y_mso_km', 'z_mso_km', 'jump_ratio', 'indicator'] 'time'：采用YYYY-MM-DD HH:mm:SS格式的日期与时间 'orbit_number'：信使号任务的轨道编号 'x_mso_km'：未像差校正的水星太阳坐标系（Mercury Solar Orbital coordinate system, MSO）x坐标位置，单位为千米 'y_mso_km'：未像差校正的水星太阳坐标系y坐标位置，单位为千米 'z_mso_km'：未像差校正的水星太阳坐标系z坐标位置，单位为千米 'jump_ratio'：选定穿越事件前后的平均磁场比值 'indicator'：质量等级标识，取值为1、2或3（1：事件极清晰，最高质量；2：事件清晰，良好质量；3：事件模糊，较差质量） 若用于后续分析，建议仅使用质量等级标识为1和2的穿越事件。时间测定的不确定度为±2秒。 分析轨道总数：3982条 共识别到穿越事件13502次 质量等级1（事件极清晰，最高质量）的穿越事件：1765次 质量等级2（事件清晰，良好质量）的穿越事件：5027次 质量等级3（事件模糊，较差质量）的穿越事件：6710次 版本1： 本文件收录了水星弓激波（bow shock）穿越事件列表，这些事件基于分辨率为1秒的信使号（MESSENGER）任务磁场数据（未像差校正）识别得到，数据来源：https://pds-ppi.igpp.ucla.edu/。 为预选包含弓激波穿越事件的时段，我们采用了Philpott（2020）发布的列表《信使号弓激波与磁层顶穿越事件》（https://doi.org/10.5683/SP2/1U6FEO）。该列表收录了入轨/出轨段的首次与末次穿越事件（入轨段的边界编号为1和2，出轨段为7和8）。针对弓激波识别，我们对上述时段向两侧各延伸15秒后应用自动检测算法。 该算法对相邻15秒时段内的磁场强度计算滑动平均与方差，两个时段间隔2秒（间隙时段）。当前后平均磁场的比值超过阈值（默认值为1.4）时，即判定为一次弓激波穿越。若10秒内存在多个比值峰值，则仅选取对应相邻时段方差和最小的那个峰值。穿越事件将根据平均磁场比值与对应方差进行检测质量分级。详细信息可参见随本文件一同发布的算法脚本。 列表文件的列字段如下：['time', 'orbit_number', 'x_mso_km', 'y_mso_km', 'z_mso_km', 'in/out', 'jump_ratio', 'indicator'] 'time'：采用YYYY-MM-DD HH:mm:SS格式的日期与时间 'orbit_number'：信使号任务的轨道编号 'x_mso_km'：未像差校正的水星太阳坐标系x坐标位置，单位为千米 'y_mso_km'：未像差校正的水星太阳坐标系y坐标位置，单位为千米 'z_mso_km'：未像差校正的水星太阳坐标系z坐标位置，单位为千米 'in/out'：轨道的入轨/出轨段（远心点朝向近心点，或近心点朝向远心点） 'jump_ratio'：选定穿越事件前后的平均磁场比值 'indicator'：质量等级标识，取值为1、2或3（1：事件极清晰，最高质量；2：事件清晰，良好质量；3：事件模糊，较差质量） 若用于后续分析，建议仅使用质量等级标识为1和2的穿越事件。时间测定的不确定度为±2秒。 分析轨道总数：3982条 共识别到穿越事件65666次 质量等级1（事件极清晰，最高质量）的穿越事件：4291次 质量等级2（事件清晰，良好质量）的穿越事件：16652次 质量等级3（事件模糊，较差质量）的穿越事件：44723次