doi:10.5067/GNSS/guardian_ionotec_001

• Data Center Citation
• Data Citation
• Summary
• Description
• Data Access
• Documentation

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.

More information about CDDIS data citations and acknowledgments is available.

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 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

Code	Meaning
YYYY	4-digit year
DDD	3-digit day of year
SITE	four-letter code for a ground-based GNSS station/receiver
YY	2-digit year
MM	2-digit month
DD	2-digit day
.CSV	comma separated value file

Description of fields in the CSV files:

Field	Description
GPSSoD	the GPS seconds of day (i.e., seconds since midnight on the day of the file)
UTCTime	the 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)
sat	the satellite Space Vehicle Number (SVN)
ipplat	the latitude of the ionospheric pierce point (IPP) for the link between the site (<SITE> of the corresponding file) and the satellite (sat field)
ipplon	the longitude of the ionospheric pierce point (IPP) for the link between the site (<SITE> of the corresponding file) and the satellite (sat field)
atec	absolute (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)
stec	filtered (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)
dataflag	informative 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

https://datatracker.ietf.org/doc/html/rfc4180