<?xml version="1.0" encoding="UTF-8"?>
<Instrument xmlns="https://metadata.pithia.eu/schemas/2.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xlink="http://www.w3.org/1999/xlink" xsi:schemaLocation="https://metadata.pithia.eu/schemas/2.2 https://metadata.pithia.eu/schemas/2.2/pithia.xsd">
<identifier>
<PITHIA_Identifier>
<localID>Instrument_WHISPER</localID>
<namespace>iasb</namespace>
<version>1</version>
<creationDate>2022-09-14T12:00:00Z</creationDate>
<lastModificationDate>2024-03-05T14:00:00Z</lastModificationDate>
</PITHIA_Identifier>
</identifier>
<name>WHISPER: Waves of High frequency and Sounder for Probing of Electron density by Relaxation</name>
<description>
The WHISPER (Waves of High frequency and Sounder for Probing of Electron density by Relaxation) experiment
measures the electric field fluctuations in the range 2-80 kHz. It fulfils two functions/modes: (1) In active
operations, it measures the total electron density via an active radio-frequency technique, the relaxation
sounder. (2) In passive operations, it provides a survey of natural emissions in the range 2-80 kHz, range
which covers the electron plasma resonance frequency in most regions explored by the Cluster satellites.
</description>
<type xlink:href="https://metadata.pithia.eu/ontology/2.2/instrumentType/InSituRelaxationSounder"/>
<operationalMode>
<InstrumentOperationalMode>
<id>sounding</id>
<name>Active sounding</name>
<description>
WHISPER measures the total electron density via an active radio-frequency technique, the relaxation sounder.
</description>
</InstrumentOperationalMode>
</operationalMode>
<operationalMode>
<InstrumentOperationalMode>
<id>listening</id>
<name>Passive sounding</name>
<description>
WHISPER provides a survey of natural emissions in the range 2-80 kHz, range which covers the electron plasma resonance frequency in most regions explored by the Cluster satellites.
</description>
</InstrumentOperationalMode>
</operationalMode>
</Instrument>
