Abstract:
This dataset contains unprocessed and processed high frequency radar (HFR) data from the MARA Codar SeaSonde site. This site is located on Marathon, FL and is positioned facing South over the loop current in the Straits of Florida region of the Gulf of Mexico. HFR are used to record observed Doppler spectrum of sea surface wave echoes which contain current and wave information that can processed into usable data. The data starts on 2019-12-16 and ends on 2022-02-01. The real-time data for this site is used for oceanographic model data assimilation and validation which help us to better understand the evolution of the Loop Current System. This site is owned and operated by the University of South Florida as part of the Understanding Gulf Ocean Systems (UGOS) project funded by the National Science Foundation (NSF).
Suggested Citation:
Clifford Merz, Michael Smith. Marathon, Fl (MARA) HFR - Codar SeaSonde - Raw Data. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/M6XBD0TV
Data Parameters and Units:
AISData
Automatic Identification System positional reports used for antenna-pattern checks
Parameter Unit / Type
MMSI (vessel ID) unitless
Latitude / Longitude decimal deg (WGS-84)
Speed over ground knots
Course over ground degrees (T)
Timestamp ISO-8601 UTC
BackupConfigs
Archived SeaSonde configuration bundles
Parameter Unit / Type
CFG / INI / TXT files text (metadata)
Antenna gain & phase tables dimensionless
Center frequencies MHz
Software release manifest semantic version
Diagnostics (STAT_*.{rdt,xdt,sdt,hdt})
(Spectra, radial & hardware “health” snapshots)
Field code (examples) Meaning Typical unit
TIME / DMIN offset from %TimeStamp s or min
AMP1, AMP2 loop↔monopole amplitude correction ratio
PH13, PH23, CPH1, CPH2 relative phase deg
SNF1-3, SSN1-3; SNF / SBW / SSP in XDT noise floor, Bragg width, S/N dB / Hz
DGRC, RBEG–REND range-cell index count
DOPV, RADV, RAPR … doppler/vector counts count
RADR furthest valid range km
RMCV / RACV max / mean current speed cm s⁻¹
RABA mean bearing deg (T)
RTMP, MTMP, XPHT… cabinet / amplifier temps °C
SP05, XP28… internal rails V
XAFW / XARW forward / reflected RF power W
X1VR VSWR ratio
Source PDFs: Radial Diag RDT File_STAT_RDT | Spectra Diag XDT File_STAT_XDT | Point-Diag SDT File_STAT_SDT | Hardware HDT File_STAT_HDT
Radials (*.ruv / LLUV RDL*)
SeaSonde current component toward the radar
Parameter Unit
LOND / LATD decimal deg
VELU, VELV, VELO cm s⁻¹
HEAD (direction) deg (T)
XDST / YDST / RNGE km
BEAR (radial azimuth) deg (T)
ESPC, ETMP cm s⁻¹ (σspatial, σtemporal)
MAXV / MINV cm s⁻¹
SPRC range-cell index
VFLG bit-mapped quality flag
(Full list in LLUV spec File_LLUV)
RangeSeries (Rng_*.rs)
FFT sweeps of power vs slant-range
Parameter Unit
Range-cell distance km (fRangeCellDistKm)
Channel / antenna index integer
Received power dB (after scal factor)
Sweep index count
Timestamp seconds-since-1904 (UTC)
See Range-Series format File_Range_Series
Spectra (CSQ/CSS/CSA *.cs, CSR_*.csr)
Doppler cross-spectra used for currents & waves
Parameter Unit
Doppler bin frequency Hz
Range-cell distance km
Self-spectra (A1–A3) V² (linear) → dB
Cross-spectra mag (C12M, …) V² / dB
Cross-spectra phase (C12A, …) deg
Quality array 0–1
Bragg limits doppler-index
Timestamp seconds-since-1904 UTC
(Standard v6 spec File_Cross_Spectra_V6; reduced CSR variant FIle_Reduced_Spectra)
Methods:
Data was recorded in real time at the Marathon, FL HFR site (MARA). A HF signal is propagated at the ocean water surface and travels beyond the horizon. The radar signal reflects off of ocean waves and return to source. The returning signal exhibits a Doppler-frequency shift. This signal is saved in the form of observed ocean spectrum maps which are produced approximately every 20 minutes. These spectra are filtered, averaged, and processed into hourly radial current maps.