Raw microwave brightness readings (SMAP) — SPL1BTB

In plain English

What it measures. Raw, calibrated microwave brightness temperature readings (how warm the surface looks to a microwave sensor), tied to specific spots on Earth and ordered in time, with stray and erroneous signals removed.

How it's made. Produced directly from the SMAP satellite's passive microwave radiometer at an early processing stage, with corrections applied to reference the readings to the surface.

How & where you'd use it. A building-block input mainly used to generate higher-level products like soil moisture maps, rather than something most people use on its own.

What's measured

SPECTRAL/ENGINEERING › MICROWAVE › BRIGHTNESS TEMPERATURE

Coverage & cadence

Time span2015-03-31 → ongoing
Measured bySMAP (SMAP L-BAND RADIOMETER)
Processing levelLevel 1B
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

This Level-1B (L1B) product provides calibrated estimates of time-ordered geolocated brightness temperatures measured by the Soil Moisture Active Passive (SMAP) passive microwave radiometer. SMAP L-band brightness temperatures are referenced to the Earth's surface with undesired and erroneous radiometric sources removed.

Get the data

spl1btb_access.py

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

results = earthaccess.search_data(
    short_name="SPL1BTB",
    version="006",
    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.

What's measured

Coverage & cadence

What you can do with it

Get the data

Official links