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Full catalog/SPL1AP
SPL1AP·v002·dataset

Raw radio signal records from SMAP's antenna

SMAP L1A Radiometer Time-Ordered Parsed Telemetry V002
land NASA NSIDC_CPRD Level 1A active HDF5
In plain English

What it measures. These are the raw, time-ordered signal records straight from SMAP's radiometer antenna, given as scaled instrument counts for its various channels and polarizations. It is the unprocessed feed of what the antenna detected.

How it's made. Each file holds all the radiometer data downlinked from NASA's SMAP spacecraft for one half-orbit, parsed from the satellite's telemetry but not yet turned into geophysical measurements.

How & where you'd use it. This is a low-level building-block product. Most people benefit from it indirectly through SMAP's higher-level soil moisture products rather than using it directly.

What's measured

SPECTRAL/ENGINEERING › MICROWAVE › SENSOR COUNTS

Coverage & cadence

  • Time span2015-03-31 → ongoing
  • Measured bySMAP (SMAP L-BAND RADIOMETER)
  • Processing levelLevel 1A
  • Spatial extent-180, -86.4, 180, 86.4
  • FormatsHDF5
  • 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

Each Level-1A (L1A) granule incorporates all radiometer data downlinked from the Soil Moisture Active Passive (SMAP) spacecraft for one specific half orbit. The data are scaled instrument counts consisting of the first four raw moments of the fullband channel (vertical and horizontal polarizations); the complex cross-correlations of the fullband channel; and the 16 subband channels (vertical and horizontal polarizations).

Get the data

spl1ap_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="SPL1AP",
    version="002",
    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 NSIDC_CPRD
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.