TGO Ramfjordmoen Ionosonde Data May 1990

About this dataset: This dataset contains ionograms in PNG format and covers data from May 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：本数据集包含PNG格式的电离层图像，覆盖了1990年5月1日至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附近拉姆福约登的69°35'N，19°13'E处，由特罗姆瑟大学极光观测站操作。该仪器在此地自1984年之前便开始运行，截至2018年仍在该地运行；具体详情请参阅相关出版物。该仪器基于惠普21MX计算机进行了全面数字化处理。低功率发射机和互补码传输的结合使得特罗姆瑟电离层探测仪（在当时）与传统的电离层探测仪相当，具有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像拍摄，频率扫描从1兆赫兹至12兆赫兹，持续时间为2至3分钟。对于100公里高度区域，确定稀疏E层高度精度为±3公里。电离层图像存储在磁带上。计算机程序中的噪声识别程序将存储数据减少至原始数据的10%以下。因此，一条2400英尺的磁带可以存储大约1300个电离层图像，相当于18天的数据。当读取这些磁带时，它们已有4至11年的历史，导致在转移至其他媒体的过程中损失了大约20%的数据。如今，数据存储在在线磁盘上，并备份于多种离线介质上。