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Full catalog/N09_AVH09C1
N09_AVH09C1·v6·dataset

True surface colors, daily (NOAA-9, 0.05 deg)

NOAA-09 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. A daily global map of the true surface colors of the land as seen from space, with the haze of the atmosphere removed, at about 5-kilometer resolution.

How it's made. Generated from the older NOAA-9 satellite's AVHRR sensor as part of a long-term climate data record, with corrections applied to strip out atmospheric effects and viewing-angle differences.

How & where you'd use it. Part of a decades-spanning record used to study global climate change and vegetation trends, and a building block for derived measures like vegetation greenness.

What's measured

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

Coverage & cadence

  • Time span1985-01-04 → 1988-11-09
  • Measured byNOAA-9 (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-09 AVHRR Atmospherically Corrected Surface Reflectance Daily L3 Global 0.05Deg CMG, short-name N09_ AVH09C1 is generated from GIMMS Advanced Processing System (GAPS) BRDF-corrected Surface Reflectance product (AVH01C1). The N09_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

n09_avh09c1_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="N09_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.