MODIS/Aqua Calibrated Radiances 5-Min L1B Swath 250m V7

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.

SDS Variable Long-name EV_250_RefSB Earth View 250M Reflective Solar Bands Scaled Integers EV_250_RefSB_Uncert_Indexes Earth View 250M Reflective Solar Bands Uncertainty Indexes

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.