TGO Ramfjordmoen Ionosonde Data July 1986

About this dataset: This dataset contains ionograms in PNG format and covers data from July 01-31, 1986.About the Tromsø Ionosonde (1984-1992): During the period 1984-1992 the Ionosonde was situated at 69° 35' N, 19° 13' E at Ramfjordmoen near Tromsø, Norway and operated by the Auroral Observatory of the University of Tromsø. The instrument operated at this location prior to 1984, and still operates there (as of 2018); see the related publication for details. The instrument was fully digitized and based on a Hewlett Packard 21MX computer. The combination of a low power transmitter and complementary code transmission made the Tromsø ionosonde equivalent to a conventional ionosonde (at the time) with 20 µs pulses and 16 kW peak power. Routine operation was one ionogram every 20 min with a frequency sweep from 1 MHz to 12 MHz lasting between 2 and 3 min. For the 100 km altitude region the precision of determining the height of a sporadic E layer is ± 3 km. The ionograms were stored on magnetic tape. A noise discrimination routine in the computer program reduced the stored data to less than 10% of the raw data. In this way one 2400' tape held about 1300 ionograms, equivalent to 18 days' data. The tapes were 4-11 years old when they were read, resulting in around 20% data-loss during the process of transferring to other media. Today, storage is on online disk and with offline an archive on a variety of media.关于本数据集：本数据集包含PNG格式的电离图（ionogram），涵盖1986年7月1日至31日的观测数据。 特罗姆瑟电离层探测仪（Tromsø Ionosonde，1984-1992年）概况：1984至1992年间，该探测仪部署于挪威特罗姆瑟附近的拉姆峡湾莫恩（Ramfjordmoen），地理坐标为北纬69°35′、东经19°13′，由特罗姆瑟大学极光观测台负责运维。该仪器在1984年之前便已在此处运行，且截至2018年仍持续工作，详细信息可参阅相关研究论文。本仪器已实现全数字化，搭载惠普（Hewlett Packard）21MX型计算机。低功耗发射机与互补码传输技术的结合，使得该特罗姆瑟电离层探测仪的性能等效于当时配备20 μs脉冲、峰值功率16 kW的传统电离层探测仪。常规运行模式为每20分钟获取一张电离图，扫描频率范围为1 MHz至12 MHz，单次扫描耗时2至3分钟。在100公里高度区间内，偶发E层（sporadic E layer）的高度测定精度为±3 km。此前电离图均存储于磁带上，计算机程序中的噪声甄别程序可将存储数据压缩至原始数据的10%以内。以此方式，一盘2400英尺长的磁带可存储约1300张电离图，相当于18天的观测数据量。待读取时，这些磁带已有4至11年的存储时长，因此在向其他介质迁移的过程中约有20%的数据丢失。如今，该数据集已在线存储于磁盘，并通过多种介质实现离线归档。