TGO Ramfjordmoen Ionosonde Data July 1990

About this dataset: This dataset contains ionograms in PNG format and covers data from July 01-31, 1990.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：本数据集收录了PNG格式的电离层图，涵盖1990年7月1日至7月31日的数据。关于特罗姆瑟电离层探测仪（1984-1992年）：在1984年至1992年期间，特罗姆瑟电离层探测仪位于挪威特罗姆瑟市拉姆福尔登附近，纬度69°35' N，经度19°13' E，由特罗姆瑟大学极光观测站运营。该仪器在1984年之前便已在此地运行，并且直至2018年仍在使用；详情请参阅相关出版物。该仪器基于惠普21MX计算机完全数字化，结合低功率发射机和互补码传输，使特罗姆瑟电离层探测仪在当时等同于常规电离层探测仪，具备20微秒脉冲和16千瓦峰值功率。常规操作为每20分钟进行一次电离层图记录，频率扫描从1兆赫兹至12兆赫兹，持续时长在2至3分钟之间。对于100公里高度区域，对稀疏E层高度的确定精度为±3公里。电离层图存储在磁带上。计算机程序中的噪声识别程序将存储数据降低至原始数据的不到10%。通过这种方式，一根2400英尺的磁带可存储约1300张电离层图，相当于18天的数据。当读取这些磁带时，由于转换至其他介质的过程中，数据损失约为20%。如今，数据存储于在线磁盘上，并设有离线存档，存储于多种介质之中。