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Full catalog/N09_AVH02C1
N09_AVH02C1·v6·dataset

Sunlight reflected at the top of the air (NOAA-09, daily)

NOAA-09 AVHRR Top-of-Atmosphere Reflectance Daily L3 Global 0.05 Deg. CMG
atmosphere NASA LAADS Level 3 HDF-EOS
In plain English

What it measures. A daily, global record of how much sunlight is reflected back at the very top of the atmosphere, before atmospheric effects are removed, as seen by an older weather satellite.

How it's made. Generated from the AVHRR instrument on the NOAA-09 satellite as part of a long-term climate data record that bridges decades of AVHRR, MODIS, and VIIRS observations, on a roughly 5.6-km grid.

How & where you'd use it. An early-stage input in building consistent decades-long climate records, including vegetation greenness; mainly used by researchers assembling long-term land-surface datasets.

What's measured

ATMOSPHERE › ATMOSPHERIC RADIATION › REFLECTANCE › TOP OF ATMOSPHERE (TOA) REFLECTANCELAND SURFACE › SURFACE RADIATIVE PROPERTIES › REFLECTANCESPECTRAL/ENGINEERING › INFRARED WAVELENGTHS › BRIGHTNESS TEMPERATURE

Coverage & cadence

  • Time span1985-01-04 → 1988-11-30
  • Measured byNOAA-9 (AVHRR)
  • Processing levelLevel 3
  • Spatial extent-180, -90, 180, 90
  • FormatsHDF-EOS
  • 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

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 Top-of-Atmosphere Reflectance Daily L3 Global 0.05 Deg. CMG, short-name N09_AVH02C1 is generated from GIMMS Advanced Processing System (GAPS) BRDF-corrected Surface Reflectance product (AVH01C1). The N09_AVH02C1 consist of Top-of-atmosphere reflectance for bands 1 and 2, data Quality flags, angles (solar zenith, view zenith, and relative azimuth), thermal data (thermal bands 3, 4 and 5), and additional data (scan time).

Get the data

n09_avh02c1_access.py
import earthaccess
earthaccess.login(strategy="netrc")          # free Earthdata Login

results = earthaccess.search_data(
    short_name="N09_AVH02C1",
    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.