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Full catalog/MYD021KM
MYD021KM·v7·dataset

Calibrated raw satellite imagery (Aqua, 1 km)

MODIS/Aqua Calibrated Radiances 5-Min L1B Swath 1000m V7
land NASA LAADS Level 1B active NetCDF-4
In plain English

What it measures. Calibrated, location-tagged measurements of how much light and energy the Aqua MODIS sensor recorded across 36 color bands, at 1-kilometer detail. It's the polished version of the satellite's raw counts, with brightness given in physical energy units.

How it's made. Produced from the MODIS instrument on NASA's Aqua satellite by converting raw sensor counts into calibrated radiances and pinning down their geographic locations (Level 1B).

How & where you'd use it. A foundational input product. Scientists use it to build higher-level MODIS products on land, ocean, and atmosphere, so most people benefit from it indirectly through those finished datasets.

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
  • FormatsNetCDF-4
  • 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 Aqua MODIS (Moderate resolution Imaging Spectroradiometer) Level-1B (L1B) product includes calibrated and geolocated at-aperture radiances for 36 bands generated from MODIS Level-1A raw sensor counts. The radiances are provided in watts/m2/micrometer (µm)/steradian. The Aqua MODIS L1B product is a set three datasets (MYD02QKM, MYD02HKM, and MYD021KM) that are produced to address the three spatial-resolution variations: 250 m, 500 m, and 1000 m. This 1000-meter product is with a short-name MYD021KM. It provides 1000-m calibrated radiances for the 29 Visible and Near-Infrared (VNIR) (bands 8 to 19) and Shortwave Infrared and Thermal Infrared (SWIR & TIR) (bands 20 to 36) bands. Each 1-km band has 10 detectors in the along-track direction. The MYD021KM product contains the twelve Science Data Sets (SDS) besides geolocation fields for latitude and longitude, quality flags, error estimates, etc. Besides data and information for the 1-km reflective solar and thermal emissive bands, aggregated 250-m and 500-m bands are also generated through simple weighting functions that are applied to the data at their native resolution. Band 26 is a reflective solar band (RSB), which is handled uniquely. Notwithstanding its RSB status, it is transmitted along with the thermal band data. Consequently, the band order for the night-mode data is re-organized so that the Band 26 data are written to the RSB 1-km SDSs and not to the emissive band SDSs. The v7.0 Aqua MODIS MYD021KM in netCDF4 format represents the most current version of this product that has undergone around half-a-dozen reprocessing cycles in the last 2.5 decades. Each 1000-m swath granule or data-file temporally spans 5 minutes and its image dimensions measure 2,030 lines (along-track direction) by 1,354 samples (cross-track direction). The v7.0 collection’s data record starts from July 4, 2002 (2002–185). Consult the MODIS L1B User Guide to understand how to convert the per-pixel scaled integers to radiance or reflectance.

Get the data

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

results = earthaccess.search_data(
    short_name="MYD021KM",
    version="7",
    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.