juYYMMDDmpa?.png - Most Probable Amplitude (MPA, similar to noise) for each frequency
juYYMMDDamp.png - Maximum VI amplitude for each frequency, <80 < E < 160> <180 < F < 1000>
juYYMMDDsnr.png - Maximum VI SNR (MaxAmp-MPA) for each frequency
juYYMMDDhgt.png - OI Amplitude @ 1760 kHz for each height
juYYMMDD-fffff.png - VI Amplitude @ (f) kHz for each height
x-axis is UT time of that day - normally 5-minute measurements
Frequency resolution is 50 kHz