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Full catalog/MYD021KM
MYD021KM·v6.1·dataset

Calibrated raw imagery (Aqua, 1 km)

MODIS/Aqua Calibrated Radiances 5-Min L1B Swath 1km
land NASA LAADS Level 1B active HDF-EOS
In plain English

What it measures. Records how much light and heat the sensor detected across 36 wavelength bands from visible light to thermal infrared, converted into standard physical units, with location info, quality flags, and error estimates.

How it's made. Comes from the MODIS instrument on NASA's Aqua satellite; raw scans are calibrated and tagged with their ground locations, but not yet turned into specific environmental measurements.

How & where you'd use it. A foundational input product: scientists rarely use it directly, instead relying on the many higher-level land, ocean, and atmosphere products built from these calibrated measurements.

What's measured

SPECTRAL/ENGINEERING › INFRARED WAVELENGTHS › INFRARED RADIANCESPECTRAL/ENGINEERING › INFRARED WAVELENGTHS › REFLECTED INFRAREDSPECTRAL/ENGINEERING › VISIBLE WAVELENGTHS › VISIBLE RADIANCE

Coverage & cadence

  • Time span2002-07-04 → ongoing
  • Measured byAqua (MODIS)
  • Processing levelLevel 1B
  • Spatial extent-180, -90, 180, 90
  • FormatsHDF-EOS
  • 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 MODIS/Aqua Calibrated Radiances 5Min L1B Swath 1km data set contains calibrated and geolocated at-aperture radiances for 36 discrete bands located in the 0.4 to 14.4 micron region of the electromagnetic spectrum. These data are generated from the MODIS Level 1A scans of raw radiance which during processing are converted to geophysical units of W / (m^2 um sr). Additional data are provided including quality flags, error estimates and calibration data. Visible, shortwave infrared, and near infrared measurements are only made during the daytime (except band 26), while radiances for the thermal infrared region (bands 20-25, 27-36) are measured continuously. The shortname for this product is MYD021KM and is stored in the Earth Observing System Hierarchical Data Format (HDF-EOS). A typical file size is approximately 115 MB. Environmental information derived from MODIS L1B measurements will offer a comprehensive and unprecedented look at terrestrial, atmospheric, and ocean phenomenology for a wide and diverse community of users throughout the world. See the MODIS Characterization Support Team webpage for more C6 product information at: https://mcst.gsfc.nasa.gov/l1b/product-information or visit Science Team homepage at: https://modis.gsfc.nasa.gov/data/dataprod/

Get the data

myd021km_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="MYD021KM",
    version="6.1",
    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 LAADS
Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.