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AWESOME receiver system narrowband VLF data

(2020). AWESOME receiver system narrowband VLF data [Data set]. Worldwide Archive of Low frequency Data and Observations (WALDO). https://doi.org/10.48322/6t7b-s324. Accessed on .

ResourceID
spase://ISWI/NumericalData/AWESOME/VLF/PT0.02S

Description

Most of the data is collected on two air-core loop
antennas, oriented orthogonal, to collect the two horizontal
components of the magnetic field. The north-south, or N/S antenna
is sensitive mostly to waves arriving from the north of from the
south direction, meaning it picks up the magnetic field component
in the east-west direction. The other antenna is the east-west
antenna, which is the opposite.

Narrowband data are the amplitudes and phase of specific
frequencies, usually corresponding to VLF transmitters that are
used for communications and navigation. Sampling rate is usually
either 1 Hz or 50 Hz. They are also useful as a diagnostic of the
ionosphere. Most of these transmitters use minimum shift keying
(MSK) modulation, and the recording software extracts the
amplitude, and the phase is calculated by demodulating the MSK
demodulation. Details of the demodulation algorithm and examples of
its application can be found in Gross, N.C.; Cohen, M.B.; Said,
R.K.; Golkowski, M, "Polarization of Narrowband VLF
Transmitter Signals as Ionospheric Diagnostic", JGR, 2018,
901-917. https://doi.org/10.1002/2017JA024907

Narrowband files available in the WALDO archive are in 24-hour blocks, so the start
time of all files is 00:00:00 UT, and the end time is 24:00:00
UT. Even if only a small amount amount of data was recorded on a
given day, the file on WALDO will contain 24-hours worth of
samples. This is done to make the analysis easier, since all files
have the same start time. The raw original data actually starts a
new set of files whenever the computer or software reboots, but
the archivists made the effort of stitching them together. Where data were
not actually recorded, the value will be “NaN” or not a number.

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Details

Version:2.3.1

NumericalData

ResourceID
spase://ISWI/NumericalData/AWESOME/VLF/PT0.02S
ResourceHeader
ResourceName
AWESOME receiver system narrowband VLF data
DOI
https://doi.org/10.48322/6t7b-s324
ReleaseDate
2021-03-02 17:39:48Z
Description

Most of the data is collected on two air-core loop
antennas, oriented orthogonal, to collect the two horizontal
components of the magnetic field. The north-south, or N/S antenna
is sensitive mostly to waves arriving from the north of from the
south direction, meaning it picks up the magnetic field component
in the east-west direction. The other antenna is the east-west
antenna, which is the opposite.

Narrowband data are the amplitudes and phase of specific
frequencies, usually corresponding to VLF transmitters that are
used for communications and navigation. Sampling rate is usually
either 1 Hz or 50 Hz. They are also useful as a diagnostic of the
ionosphere. Most of these transmitters use minimum shift keying
(MSK) modulation, and the recording software extracts the
amplitude, and the phase is calculated by demodulating the MSK
demodulation. Details of the demodulation algorithm and examples of
its application can be found in Gross, N.C.; Cohen, M.B.; Said,
R.K.; Golkowski, M, "Polarization of Narrowband VLF
Transmitter Signals as Ionospheric Diagnostic", JGR, 2018,
901-917. https://doi.org/10.1002/2017JA024907

Narrowband files available in the WALDO archive are in 24-hour blocks, so the start
time of all files is 00:00:00 UT, and the end time is 24:00:00
UT. Even if only a small amount amount of data was recorded on a
given day, the file on WALDO will contain 24-hours worth of
samples. This is done to make the analysis easier, since all files
have the same start time. The raw original data actually starts a
new set of files whenever the computer or software reboots, but
the archivists made the effort of stitching them together. Where data were
not actually recorded, the value will be “NaN” or not a number.

Acknowledgement
DATA USAGE POLICY The data in the WALDO database have been collected by Stanford University, the Georgia Institute of Technology, and the University of Colorado Denver. Funding has been provided by the United States government under various basic science research grants over many years. To maximize the benefit of those investments, WALDO data are released without restriction, and can be freely analyzed or published. The curators of WALDO are Morris Cohen (Georgia Tech) and Mark Golkowski (CU-Denver). We request that the following acknowledgement be added in any publication using data from WALDO "VLF data are provided by the WALDO database (https://waldo.world), operated jointly by the Georgia Institute of Technology, and the University of Colorado Denver, using data collected from those institutions as well as Stanford University, and has been supported by various US government grants from the NSF, NASA, and the Department of Defense." If extensive amounts of WALDO data are used in a publication, the curators request, but do not require, to be contacted to discuss the possibility of joint authorship, with the WALDO curators providing help analyzing and interpreting the large dataset.
PublicationInfo
Authors
Morris B. Cohen, Umran S. Inan, Mark A. Golkowski
PublicationDate
2020-01-01 00:00:00Z
PublishedBy
Worldwide Archive of Low frequency Data and Observations (WALDO)
Contacts
RolePerson
1.ArchiveSpecialistspase://SMWG/Person/Morris.Cohen
InformationURL
Name
Worldwide Archive of Low-Frequency Data and Observations (WALDO)
URL
PriorIDs
spase://GBO/NumericalData/AWESOME/VLF/PT0.02S
AccessInformation
RepositoryID
AccessURL
Name
Worldwide Archive of Low-Frequency Data and Observations (WALDO) Narrowband Data
URL
Format
MATLAB_4
Acknowledgement
VLF data are provided by the WALDO database (https://waldo.world), operated jointly by the Georgia Institute of Technology, and the University of Colorado Denver, using data collected from those institutions as well as Stanford University, and has been supported by various US government grants from the NSF, NASA, and the Department of Defense.
InstrumentIDs
MeasurementType
Waves.Passive
TemporalDescription
TimeSpan
StartDate
2005-04-28 00:00:00
RelativeStopDate
-P3Y
Note
Different stations have different start/stop dates
Cadence
P1D
ObservedRegion
Earth.NearSurface
ObservedRegion
Earth.NearSurface.Ionosphere
Parameter #1
Name
start_year
Support
SupportQuantity
Temporal
Parameter #2
Name
start_month
Support
SupportQuantity
Temporal
Parameter #3
Name
start_day
Support
SupportQuantity
Temporal
Parameter #4
Name
start_hour
Support
SupportQuantity
Temporal
Parameter #5
Name
start_minute
Support
SupportQuantity
Temporal
Parameter #6
Name
start_second
Support
SupportQuantity
Temporal
Parameter #7
Name
latitude
Support
SupportQuantity
Positional
Parameter #8
Name
longitude
Support
SupportQuantity
Positional
Parameter #9
Name
altitude
Support
SupportQuantity
Positional
Parameter #10
Name
Fs
Description

Sampling rate of the data, usually 100 kHz or 1 MHz.

CadenceMin
PT0.000001S
CadenceMax
PT0.00001S
Support
SupportQuantity
Other
Parameter #11
Name
gps_quality
Support
SupportQuantity
DataQuality
Parameter #12
Name
adc_channel_number
Support
SupportQuantity
Other
Parameter #13
Name
adc_sn
Support
SupportQuantity
Other
Parameter #14
Name
adc_type
Support
SupportQuantity
Other
Parameter #15
Name
antenna_bearings
Support
SupportQuantity
Orientation
Parameter #16
Name
antenna_description
Support
SupportQuantity
InstrumentMode
Parameter #17
Name
cal_factor
Support
SupportQuantity
Other
Parameter #18
Name
computer_sn
Support
SupportQuantity
Other
Parameter #19
Name
gps_sn
Support
SupportQuantity
Other
Parameter #20
Name
hardware_description
Support
SupportQuantity
InstrumentMode
Parameter #21
Name
is_broadband
Support
SupportQuantity
InstrumentMode
Parameter #22
Name
station_description
Support
SupportQuantity
Other
Parameter #23
Name
station_name
Support
SupportQuantity
Other
Parameter #24
Name
VERSION
Support
SupportQuantity
Other
Parameter #25
Name
is_amp
Support
SupportQuantity
Other
Parameter #26
Name
is_msk
Support
SupportQuantity
Other
Parameter #27
Name
Fc
Description

the center frequency of the VLF transmitter (for
narrowband data)

Support
SupportQuantity
Other
Parameter #28
Name
call_sign
Support
SupportQuantity
Other
Parameter #29
Name
filter_taps
Support
SupportQuantity
Other
Parameter #30
Name
data
Wave
WaveType
Electromagnetic
WaveQuantity
ACMagneticField
FrequencyRange
SpectralRange
RadioFrequency
Low
0.3
High
50
Units
kHz