Calibrated full-Earth sunlit images (DSCOVR EPIC, ver 3)
What it measures. Calibrated images of the entire sunlit side of Earth taken in ten color bands from ultraviolet to near-infrared, capturing how much light the camera recorded across the whole disk of the planet.
How it's made. Produced by the EPIC camera on NOAA's DSCOVR spacecraft, which sits about a million miles out at a point between Earth and the Sun, with calibrations and corrections applied to clean up the raw pictures.
How & where you'd use it. These corrected images feed studies of ozone, airborne particles, clouds, vegetation, and surface ultraviolet light. They are mostly a starting point that scientists turn into those higher-level products.
What's measured
Coverage & cadence
- Time span2015-06-13 → ongoing
- Measured byDSCOVR (CCD IMAGER, EPIC)
- Processing levelLevel 1B
- FormatsHDF5
- StatusACTIVE
What you can do with it
- Map air pollutants — NO₂, aerosols, ozone
- Track greenhouse gases and Earth's energy budget
- Feed weather and air-quality analysis
Official description
Deep Space Climate Observatory (DSCOVR) Earth Polychromatic Imaging Camera (EPIC) is a 10-channel spectro-radiometer (317 – 780 nm) onboard National Oceanic and Atmospheric Administration's (NOAA) DSCOVR spacecraft located at the Earth-Sun Lagrange-1 (L-1) point giving EPIC a unique angular perspective that is used in science applications to measure ozone, aerosols, cloud reflectivity, cloud height, vegetation properties, and ultraviolet (UV) radiation estimates at Earth's surface. EPIC provides ten narrow-band spectral images of the entire sunlit face of the Earth using a 2048x2048 pixel Charge Coupled Device (CCD) detector coupled to a 30-cm aperture Cassegrain telescope. EPIC collects radiance data from the Earth and other sources through the Camera/Telescope Assembly. EPIC has a field of view (FOV) of 0.62 degrees, sufficient to image the entire Earth. Because of DSCOVR's tilted (Lissajous) orbit about the L‐1 point, the apparent angular size of the Earth varies from 0.45 to 0.53 degrees within its 6-month orbital period. Depending on the season, a complete set of per-band images is taken every 60 to 100 minutes. Accompanying instrument metadata and a series of calibrations and corrections are applied to convert the images to Level 1A format properly. The significant corrections are for flat‐fielding and stray light. Flat-fielding is based on measurements with a uniform light source to measure the differences in sensitivity for each of the 4 million pixels. The resulting correction map is applied to the estimated counts from the CCD. Stray light was measured in the laboratory using a series of small-diameter light sources entering the telescope and imaged on the CCD. A similar set of measurements has been performed on orbit using the moon. The illumination of pixels outside the primary diameter of the light source was measured to produce a detailed matrix map of the entire stray light function, and the resulting stray light correction was applied to every image. Other corrections are also used based on laboratory measurements. For wavelengths longer than 550 nm, there are back-to-front interference effects in the partially transparent CCD (etaloning) that must also be removed from measured radiance. The Level 1B products contain calibrated and geolocated EPIC images with ancillary metadata. These data products are in HDF5 format.
Get the data
import earthaccess
earthaccess.login(strategy="netrc") # free Earthdata Login
results = earthaccess.search_data(
short_name="DSCOVR_EPIC_L1B",
version="3",
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 LARC_CLOUD Browsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package. Official links
- Earth Observation Portal Page for DSCOVR Mission Information VIEW RELATED INFORMATION
- How to cite ASDC data VIEW RELATED INFORMATION
- EPIC level 1 A & B Calibration factors table VIEW RELATED INFORMATION
- EPIC Data Format Control Book Specification, Version 3, September 19, 2018 VIEW RELATED INFORMATION
- EPIC Geolocation Quality Summary Algorithm Revision 06 Product Version 03 VIEW RELATED INFORMATION
- EPIC Geolocation and Color Imagery Algorithm Revision 6 October 10, 2019 VIEW RELATED INFORMATION
- DSCOVR - SPEC - 007 EPIC Level 0 to Level 1A Processing Algorithm Description Document VIEW RELATED INFORMATION
- Earthdata Search for DSCOVR_EPIC_L1B_3 (NASA Application to search, discover, visualize, refine, and access NASA Earth Observation data) GET DATA