Alouette-2 Topside Sounder Average Ionogram over Winkfield, United Kingdom: WNK, Latitude 51, Longitude 359

This Ionogram was digitized from the original Alouette 2 Analog Telemetry Data on 7-Track Tape using the Facilities of the Data Evaluation Laboratory at NASA GSFC, Code 500. This Data Restoration Project is headed by Dr. R.F. Benson, NASA GSFC, Code 692. Ionograms were digitized at the Rate of 40,000 16-bit samples/s. This Sample Rate is higher than the Nyquist Frequency of 30 kHz. The Sample Frequency of 40 kHz provides a Measurement every 25 ms corresponding to an Apparent Range Interval of c*t/2, where c is the Speed of Light, or 3.747 km. Each Ionogram consists of a Fixed Frequency Portion and a Swept Frequency Portion. The Time Resolution is typically 31 s.

本电离层图系从原始的Alouette 2模拟遥测数据中，采用美国国家航空航天局戈达德太空飞行中心数据评估实验室的设备，于7轨磁带上进行数字化处理所得。此项数据恢复工程由NASA GSFC的R.F. Benson博士领导，代码为692。电离层图的数字化速率达到每秒40,000个16位样本。此采样率高于30 kHz的奈奎斯特频率。40 kHz的采样频率确保每25毫秒进行一次测量，对应于光速c乘以时间t的一半，即3.747公里的视距间隔。每个电离层图由一个固定频率部分和一个扫描频率部分组成。时间分辨率通常为31秒。