Polar Plasma Wave Instrument (PWI), Low Frequency Waveform Receiver, ~0.01 sec resolution fields

Coordinate System Used: local magnetic field-aligned, a spacecraft centered coordinate system where Z is parallel to the local B-field determined from Polar MFE, X points outward and lies in the plane defined by the Z-axis and the radial vector from the earth to the spacecraft, and Y completes a right-handed system and points eastward. The X- and Z-axes are contained in the north-south plane. The three orthogonal magnetic field components are given in units of nT/Sec rather than nT because the response of the searchcoils across the passband is not flat.

In order to obtain units of nT, the data would need to be digitally filtered to the frequency of interest and then integrated over time. Integrating over the entire passband could possibly destroy the resolution of the higher frequency components since the low frequency noise, if present, will dominate. Data are bandpass filtered.

The valid range of data in the frequency domain is from 0.5 to 22.5 Hz. Reference:..Gurnett, D.A. et al, The Polar plasma wave instrument, Space Science Reviews, Vol. 71, pp. 597-622, 1995.