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Full catalog/MYD02QKM
MYD02QKM·v7·dataset

Calibrated raw imagery (Aqua, 250 m)

MODIS/Aqua Calibrated Radiances 5-Min L1B Swath 250m V7
land NASA LAADS Level 1B active NetCDF-4
In plain English

What it measures. Calibrated raw imagery from two channels (visible and near-infrared) at 250-meter detail, recorded as radiance: how much light energy reached the sensor. Each file covers a 5-minute strip of the satellite's path.

How it's made. Processed from the MODIS sensor on NASA's Aqua satellite, turning raw instrument counts into calibrated, geolocated measurements.

How & where you'd use it. A building-block input that most people use indirectly, through higher-level products like surface reflectance or vegetation maps, rather than working with it directly.

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/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 landing page describes the quarter-kilometer product with a short-name MYD02QKM. It provides calibrated radiances derived from the 250-m at-nadir visible band-1 and near-infrared band-2 that have central wavelengths at 0.645 µm and 0.858 µm, respectively. Each 250-m band has 40 detectors in the along-track direction. The MYD02QKM product contains the following two Science Data Sets (SDS) besides geolocation fields for latitude and longitude, quality flags, error estimates, etc. <html> <body> <table> <tr> <th>SDS Variable</th> <th>Long-name</th> </tr> <tr> <td>EV_250_RefSB</td> <td>Earth View 250M Reflective Solar Bands Scaled Integers</td> </tr> <tr> <td>EV_250_RefSB_Uncert_Indexes</td> <td>Earth View 250M Reflective Solar Bands Uncertainty Indexes</td> </tr> </table> </body> </html> <br> The v7.0 Aqua MODIS MYD02QKM 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 250-m swath granule or data-file temporally spans 5 minutes and its image dimensions measure 8,120 lines (along-track direction) by 5,416 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

myd02qkm_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="MYD02QKM",
    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.