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Full catalog/N18_AVH09C1
N18_AVH09C1·v6·dataset

True surface color, cleaned of haze (NOAA-18, daily)

NOAA-18 AVHRR Atmospherically Corrected Surface Reflectance Daily L3 Global 0.05 Deg. CMG
land NASA LAADS Level 3 HDF-EOS
In plain English

What it measures. Shows the true color and brightness of the land surface each day, after the haze and distortion of the atmosphere have been removed so you see the ground as it really looks.

How it's made. Derived from the AVHRR instrument on the NOAA-18 satellite as part of a long-term climate record, gridded globally at about 5 km resolution after atmospheric correction.

How & where you'd use it. Feeds long-term studies of vegetation and land change, and serves as a foundation for products like greenness indexes that track plant growth and drought over decades.

What's measured

LAND SURFACE › SURFACE RADIATIVE PROPERTIES › REFLECTANCESPECTRAL/ENGINEERING › INFRARED WAVELENGTHS › BRIGHTNESS TEMPERATURESPECTRAL/ENGINEERING › INFRARED WAVELENGTHS › REFLECTED INFRARED

Coverage & cadence

  • Time span2005-07-01 → 2010-01-31
  • Measured byNOAA-18 (AVHRR)
  • Processing levelLevel 3
  • 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 Long-Term Data Record (LTDR) produces, validates, and distributes a global land surface climate data record (CDR) that uses both mature and well-tested algorithms in concert with the best-available polar-orbiting satellite data from past to the present. The CDR is critically important to studying global climate change. The LTDR project is unique in that it serves as a bridge that connects data derived from the NOAA Advanced Very High Resolution Radiometer (AVHRR), the EOS Moderate resolution Imaging Spectroradiometer (MODIS), the Suomi National Polar-orbiting Partnership (SNPP) Visible Infrared Imaging Radiometer Suite (VIIRS), and Joint Polar Satellite System (JPSS) VIIRS missions. The LTDR draws from the following eight AVHRR missions: NOAA-7, NOAA-9, NOAA-11, NOAA-14, NOAA-16, NOAA-18, NOAA-19, and MetOp-B. Currently, the project generates a daily surface reflectance product as the fundamental climate data record (FCDR) and derives daily Normalized Differential Vegetation Index (NDVI) and Leaf-Area Index/fraction of absorbed Photosynthetically Active Radiation (LAI/fPAR) as two thematic CDRs (TCDR). LAI/fPAR was developed as an experimental product. The NOAA-18 AVHRR Atmospherically Corrected Surface Reflectance Daily L3 Global 0.05Deg CMG, short-name N18_ AVH09C1 is generated from GIMMS Advanced Processing System (GAPS) BRDF-corrected Surface Reflectance product (AVH01C1). The N18_ AVH09C1 consist of BRDF-corrected surface reflectance for bands 1, 2, and 3, data Quality flags, angles (solar zenith, view zenith, and relative azimuth), and thermal data (thermal bands 3, 4, and 5). The AVH09C1 product is available in HDF4 file format.

Get the data

n18_avh09c1_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="N18_AVH09C1",
    version="6",
    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.