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The GNSS-based Upper Atmospheric Realtime Disaster Information and Alert Network (GUARDIAN) Near-Real-Time Ionospheric Total Electron Content product doi is: 10.5067/GNSS/guardian_ionotec_001.

Data Center Citation

Noll, Carey E., The Crustal Dynamics Data Information System: A resource to support scientific analysis using space geodesy, Advances in Space Research, Volume 45, Issue 12, 15 June 2010, Pages 1421-1440, ISSN 0273-1177, http://dx.doi.org/10.1016/j.asr.2010.01.018.

Data Citation

NASA Jet Propulsion Laboratory, GUARDIAN Near-Real-Time Ionospheric Total Electron Content product, Greenbelt, MD, USA:NASA Crustal Dynamics Data Information System (CDDIS), Accessed [[enter user data access date]] at doi:10.5067/GNSS/guardian_ionotec_001.

Other standard citation formats may be used for this data set and can be found at the DOI Citation Formatter website.

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Citation

Martire, L., Krishnamoorthy, S., Vergados, P. et al. The GUARDIAN system-a GNSS upper atmospheric real-time disaster information and alert network. GPS Solut 27, 32 (2023). https://doi.org/10.1007/s10291-022-01365-6

Summary

  • Name: GUARDIAN Near-Real-Time Ionospheric Total Electron Content product
  • Format: CSV
  • Spatial Coverage: 90.0 to -90.0, 180.0 to -180.0 (∼1200 km around monitored stations)
  • Temporal Coverage: 2022-09-15 to present
  • Temporal Resolution: 5 seconds
  • File Size: ∼ 20 MB/file
  • Platforms: Multiple GNSS

Description

Developed at NASA's Jet Propulsion Laboratory (JPL), GUARDIAN is a near-real-time (NRT) ionospheric monitoring software (Martire et al.). Its main products are NRT total electronic content (TEC) time series, allowing users to explore ionospheric TEC perturbations due to natural and anthropogenic events on Earth. The NRT GUARDIAN time series are validated against well-established post-processing methods. Currently, time series are computed for more than 90 GNSS ground stations distributed around the Pacific Ring of Fire, which monitor the four main GNSS constellations (GPS, Galileo, BDS, and GLONASS).

Data Access

The GUARDIAN Near-Real-Time Ionospheric Total Electron Content products are online:

in subdirectories by year, and day of year as follows:

YYYY/DDD/SITE_YYMMDD.CSV

CodeMeaning
YYYY4-digit year
DDD3-digit day of year
SITEfour-letter code for a ground-based GNSS station/receiver
YY2-digit year
MM2-digit month
DD2-digit day
.CSVcomma separated value file

Description of fields in the CSV files:

FieldDescription
GPSSoDthe GPS seconds of day (i.e., seconds since midnight on the day of the file)
UTCTimethe UTC time in YYmmDDHHMMSS format (taking UTC leap seconds into account; with YY the 2-digit year, mm the 2-digit month, DD the 2-digit day, HH the 2-digit hours, MM the 2-digit minutes, and SS the 2-digit seconds)
satthe satellite Space Vehicle Number (SVN)
ipplatthe latitude of the ionospheric pierce point (IPP) for the link between the site (<SITE> of the corresponding file) and the satellite (sat field)
ipplonthe longitude of the ionospheric pierce point (IPP) for the link between the site (<SITE> of the corresponding file) and the satellite (sat field)
atecabsolute (uncalibrated and unfiltered) slant TEC (Total Electron Content) along the line of sight between the site (<SITE> of the corresponding file) and the satellite (sat field)
stecfiltered (high-pass with a 15-min cut-off period) TEC (Total Electron Content) along the line of sight between the site (<SITE> of the corresponding file) and the satellite (sat field)
dataflaginformative flag about this particular data point:
0 = nothing to report
5 = interpolated data point, due to a data gap
1X, 3X = a cycle slip was detected but not corrected; with:
X = 1 or 2 if slip detected on carrier phase 1 or 2 (respectively)
X = 3 if detected on both carrier phases
2X, 4X = a cycle slip was detected and a correction was attempted; with:
X = 1 or 2 if slip detected on carrier phase 1 or 2 (respectively)
X = 3 if detected on both carrier phases

Documentation

Access details about the common format and MIME type for Comma-Separated Values (CSV) files.