<?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_Ionosonde_Dynasonde</localID>
<namespace>noaa</namespace>
<version>1</version>
<creationDate>2022-11-07T14:00:00Z</creationDate>
<lastModificationDate>2022-11-07T15:48:35Z</lastModificationDate>
</PITHIA_Identifier>
</identifier>
<name>Dynasonde Advanced Ionospheric Sounder</name>
<description>
The Dynasonde evolved at NOAA between 1970-1980 as "an
ionosonde competent to measure the dynamics of the
ionosphere". In 1975, the original hardware prototype (called
"NOAA HF Radar") was selected for operational implementation;
total three copies were built by 1978. System #4 was built for
EISCAT facility in Norway; another two modernized versions
were built in the late 1980s. Continuing hardware improvements
and software development have maintained the several operating
original Dynasondes at a "state of art" functionality. In
2008, a next-generation Dynasonde hardware design was revealed
under the name Vertical Incidence Pulsed Ionospheric Radar
(VIPIR, registered separately in PITHIA). The software system for
VIPIR data analysis, Dynasonde21, retained the original title
coined in the 1970s.
</description>
<type xlink:href="https://metadata.pithia.eu/ontology/2.2/instrumentType/VerticalSounder"/> <!-- use the instrumentType ontology to describe the type of the instrument -->
<operationalMode>
<InstrumentOperationalMode>
<id>ionosounding</id>
<name>Standard ionospheric sounding </name>
<description>
The instruments perform regular ionospheric soundings,
nowadays typically down to 2 minutes. The instruments work
by transmitting sets of pulses and sampling the return
signals from individual receiving antennas in an array. The
signal is processed with the DSND and NeXtYZ algorithms
developed by N. Zabotin and coworkers. Analysed parameters
are the standard ionospheric critical frequencies and
heights, echo angles of arrival, E and F region drift
velocities, electron density profiles, and irregularity
parameters.
</description>
</InstrumentOperationalMode>
</operationalMode>
<operationalMode>
<InstrumentOperationalMode>
<id>special</id>
<name>Special modes</name>
<description>
The hardware is highly configurable and can also be used for
special purposes, e.g. single-frequency sounding. As an
example, the EISCAT Dynasonde was sometimes connected as an
exciter and receiver for HF radar measurements with the
EISCAT HF Heating facility before it was upgraded with its
present digital synthesizers and software-defined receivers,
</description>
</InstrumentOperationalMode>
</operationalMode>
</Instrument>
