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Full catalog/CYGNSS_L1_CAL_RAW_IF_V1.0
CYGNSS_L1_CAL_RAW_IF_V1.0·v1.0·dataset

Raw GPS-reflection signals for ocean wind (CYGNSS)

CYGNSS Level 1 Calibrated Raw IF Version 1.0
land NASA POCLOUD Level 1 netCDF
In plain English

What it measures. Raw, calibrated signals from GPS radio waves bouncing off the ocean surface, including various measures of how strong and coherent those reflections are — the underlying data used to gauge how rough the sea is.

How it's made. Captured by the CYGNSS constellation of small satellites, which pick up reflected navigation signals; this is the low-level calibrated 'raw intermediate frequency' stage of processing.

How & where you'd use it. A building-block input that researchers process into ocean surface wind and roughness products, especially for tracking conditions inside tropical storms and hurricanes.

What's measured

SPECTRAL/ENGINEERING › RADAR › SENSOR COUNTS

Coverage & cadence

  • Time span2018-08-01 → ongoing
  • Measured byCYGNSS (DDMI)
  • Processing levelLevel 1
  • Spatial extent-180, -38.15, 180, 38.15
  • FormatsnetCDF
  • StatusACTIVE

What you can do with it

  • Track deforestation, fire scars and land-cover change
  • Monitor crop and vegetation health (NDVI/EVI)
  • Map how built-up vs. green an area is over time
Official description

The CYGNSS Level 1 Calibrated Raw IF Version 1.0 dataset is produced by the CYGNSS Science Team of the University of Michigan, and it contains the first release, Version 1.0, of the CYGNSS Calibrated Raw Intermediate Frequency (IF) based L1 Product. CYGNSS was launched on 15 December 2016, it is a NASA Earth System Science Pathfinder Mission that was launched with the purpose of collecting the first frequent space‐based measurements of surface wind speeds in the inner core of tropical cyclones. Originally made up of a constellation of eight micro-satellites, the observatories provide nearly gap-free Earth coverage using an orbital inclination of approximately 35° from the equator, with a mean (i.e., average) revisit time of seven hours and a median revisit time of three hours. This product includes several established signal coherence detectors, including the power-ratio P<sub>ratio</sub>, complex zero-Doppler delay waveform and full entropy E<sub>full</sub>, and a novel fast entropy detector E<sub>fast</sub>. Both entropy detectors are provided with two temporal resolutions: 2 ms and 50 ms. Several scattered signal strength products are included: Signal-to-Noise Ratio SNR, reflected power P<sub>g</sub>, reflectivity Γ, and Normalized Bistatic Radar Cross-Section NBRCS. Each of these products is derived using a coherent integration time of T<sub>c </sub>= 1 ms and incoherent integration times of N<sub>inc</sub> = 1000, 500, 250, 100, 50, and 2 ms. Signal strength time series at the shorter (2 and 50 ms) times provides excellent detection of land-water transitions in heterogeneous scenes. Delay Doppler Maps (DDMs) are also generated with high delay (∆τ = 1/16 chip) and Doppler (∆f= 50 Hz) resolution. This suite of coherence detection methods can be used to detect the presence of small inland water bodies.

Get the data

cygnss_l1_cal_raw_if_v1.0_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="CYGNSS_L1_CAL_RAW_IF_V1.0",
    version="1.0",
    bounding_box=(-122.5, 37.2, -121.8, 37.9),  # your area (W,S,E,N)
    temporal=("2024-01-01", "2024-12-31"),       # your dates
)
files = earthaccess.open(results)   # stream straight from POCLOUD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.