MODIS NDVI/EVI (MOD13)¶

MODIS Vegetation Indices (MOD13Q1/A1/A2/A3/C1/C2, MYD13) Version 6.1 (NDVI and EVI, 250 m to 0.05°, 16-day and monthly)

Being replaced

At a glance¶

Note on period: Terra (MOD13) starts on 2000-02-18 and Aqua (MYD13) on 2002-07-04. A CMR check of the Korean tile (h28v05) on 2026-10-13 found the latest MOD13Q1 composite was 2026-09-14 to 29, the latest MYD13Q1 composite 2026-09-06 to 21, and the latest MOD13A3 month August 2026. MODIS data collection is expected to end when Terra and Aqua end operations.

Overview¶

The Normalized Difference Vegetation Index (NDVI) and Enhanced Vegetation Index (EVI) computed from MODIS surface reflectance and composited over 16 days and calendar months. NDVI continues the NOAA AVHRR NDVI record, while EVI uses the blue band to reduce atmospheric effects and saturates less over dense vegetation. Six resolution/period combinations run from 250 m to a 0.05° global grid, and the files also carry reflectances (red, NIR, blue, MIR), view geometry, composite day and quality information. It is one of the most widely used satellite vegetation datasets for phenology, drought, crop and land-change studies.

What changes with the successor¶

MODIS Vegetation Indices C6.1 (MOD13, MYD13) → VIIRS Vegetation Indices V2 (VNP13, VJ113, VJ213) Planned¶

Transition: 2027

The successor carries the MODIS vegetation index system over to VIIRS. CV-MVC compositing, NDVI and EVI continue, but there is no 250 m product, a different blue band weakens EVI continuity, and the two-band EVI2 has been added. Fill values, scale notation, pixel-reliability classes and file format differ, so code must be updated. MODIS collection ends with Terra and Aqua (late 2026 to 2027).

Sources: Transition from MODIS to VIIRS (NASA Earthdata notice, 2025-05-02) · VNP13 User Guide and ATBD V2.1.2 (Didan et al., 2018) · Earthdata catalog — VNP13A1 V002 (layer table) · Román et al. (2024) — continuity between MODIS C6.1 and VIIRS C2 land products (RSE)

Compare the two side by side

MODIS Vegetation Indices C6 → MODIS Vegetation Indices C6.1¶

Transition: 2023-07

A full-record reprocessing that kept the science algorithm and changed only the Terra and Aqua L1B calibration approach and the polarization correction. Format and layer names are the same as C6, and distribution of C6 (006) land products ended on 31 July 2023.

Sources: MOD13 User's Guide V3.10 (2019) · Final notice — MODIS Version 6.0 land products decommissioned (2023-07-25)

Available variables¶

From LP DAAC collection information (MOD13Q1 and MOD13A3 V061) and the MOD13 User's Guide. Layer (SDS) names are prefixed with the resolution and period (250m 16 days … for the 250 m 16-day product, 1 km monthly … for the 1 km monthly). The 500 m and 1 km 16-day and CMG products use different prefixes, so check names in your files. Index and reflectance values are int16 and are multiplied by 0.0001.

instantaneous mean accumulated maximum minimum static — instantaneous: value at the time stamp · mean/accumulated/maximum/minimum: over the indicated interval · static: does not change with time

16-day composites (MOD13Q1 250 m; A1, A2 and C1 have the same structure)¶

Monthly (MOD13A3 1 km; C2 at 0.05°)¶

The full variable list is in the official documentation.

How to get the data¶

• NASA Earthdata Search (LP DAAC, Earthdata Cloud) — Web search and HTTPS download / earthaccess
  • The link opens MOD13Q1 V061. Short names are MOD13Q1, MOD13A1, MOD13A2, MOD13A3, MOD13C1, MOD13C2 (Terra) and MYD13… (Aqua), version 061; files are HDF-EOS2 (.hdf). LP DAAC Data Pool distribution of MODIS data ended on 30 June 2025, so scripts that used Data Pool URLs should switch to Earthdata Cloud (for example via earthaccess).
• AppEEARS (area and point extraction) — Web and API — area (GeoTIFF, NetCDF4) or point (CSV) extraction with optional reprojection
  • Delivers just your region without handling tiles or the sinusoidal projection, along with quality-bit lookup tables.
• LAADS DAAC (MOD13 product page) — HTTPS download
  • Distribution point on the MODIS processing system (MODAPS) side; the file specifications (filespec) are also here.

Example code¶

Downloads Terra (MOD13Q1) and Aqua (MYD13Q1) 16-day NDVI for 2024 with earthaccess to build an 8-day-spaced series for the central Korean tile (h28v05). The files are HDF4, so pyhdf is used, and only pixel reliability 0 and 1 are kept. The actual observation day of each value is in the composite day of the year layer.

# pip install earthaccess pyhdf numpy
import earthaccess
import numpy as np
from pyhdf.SD import SD, SDC

earthaccess.login()  # free NASA Earthdata account
files = []
for sn in ("MOD13Q1", "MYD13Q1"):          # Terra and Aqua composites are offset by 8 days
    res = earthaccess.search_data(
        short_name=sn, version="061",
        temporal=("2024-04-01", "2024-10-31"),
        bounding_box=(127.0, 36.0, 127.5, 36.5),   # (west, south, east, north)
    )
    files += earthaccess.download(res, "./mod13q1")

for f in sorted(map(str, files), key=lambda p: p.split(".A")[1][:7]):
    if ".h28v05." not in f:
        continue
    sd = SD(f, SDC.READ)
    ndvi = sd.select("250m 16 days NDVI")[:].astype("float32")
    rel = sd.select("250m 16 days pixel reliability")[:]
    ndvi = np.where((ndvi >= -2000) & (rel <= 1), ndvi * 0.0001, np.nan)
    print(f.split("/")[-1][:24], "mean NDVI:", round(float(np.nanmean(ndvi)), 3))

Practical tips¶

• NDVI and EVI are stored as int16. Multiply by 0.0001 and remove the fill value −3000 and anything outside the valid range (−2000 to 10000) first. The reflectance fill is −1000 and angles are × 0.01.
• pixel reliability (0 good, 1 marginal, 2 snow/ice, 3 cloudy) is the simplest quality screen. For finer screening use bits 0–1 (quality), 2–5 (usefulness), 6–7 (aerosol), 8 (adjacent cloud), 10 (mixed clouds), 14 (snow/ice) and 15 (shadow) of VI Quality.
• A 16-day value can come from any day in the period. For day-level spring and autumn phenology (green-up and senescence dates), use composite day of the year rather than the file date.
• Mixing Terra and Aqua into an 8-day series alternates the overpass time (morning/afternoon) and sensor calibration. Do trend analysis with one satellite's product, and say so if you mix them.
• Because of orbit drift, neither satellite keeps a strict 16-day repeat any more (LP DAAC), and pixel-size and scan-gap effects grew from late 2024 (LDOPE). Cross-check small trends after the mid-2020s against the VIIRS vegetation indices.
• The monthly products (A3, C2) are weighted averages of 16-day composites, so their values behave differently from the 16-day data. If you need monthly maximum NDVI, derive it from the 16-day data yourself.
• The CMG (0.05°) products average clear 1 km pixels spatially and fill fully cloudy cells from past data. Values with pixel reliability 4 (estimated from the historical time series) are not observations and are safest left out.
• Korea spans several sinusoidal tiles, including h28v05 and h29v05, so AppEEARS or GDAL is the easier route for point extraction and reprojection.

Notices and change history¶

References for your paper¶

Dataset citation¶

MOD13Q1 V061 (Terra, 250 m, 16-day) — DOI 10.5067/MODIS/MOD13Q1.061

@misc{mod13q1_v061,
  author    = {Didan, Kamel},
  title     = {{MODIS/Terra} Vegetation Indices 16-Day {L3} Global 250m {SIN} Grid {V061}},
  year      = {2021},
  publisher = {NASA Land Processes Distributed Active Archive Center},
  doi       = {10.5067/MODIS/MOD13Q1.061}
}

MYD13Q1 V061 (Aqua, 250 m, 16-day) — DOI 10.5067/MODIS/MYD13Q1.061

@misc{myd13q1_v061,
  author    = {Didan, Kamel},
  title     = {{MODIS/Aqua} Vegetation Indices 16-Day {L3} Global 250m {SIN} Grid {V061}},
  year      = {2021},
  publisher = {NASA Land Processes Distributed Active Archive Center},
  doi       = {10.5067/MODIS/MYD13Q1.061}
}

MOD13A3 V061 (Terra, 1 km, monthly) — DOI 10.5067/MODIS/MOD13A3.061

@misc{mod13a3_v061,
  author    = {Didan, Kamel},
  title     = {{MODIS/Terra} Vegetation Indices Monthly {L3} Global 1km {SIN} Grid {V061}},
  year      = {2021},
  publisher = {NASA Land Processes Distributed Active Archive Center},
  doi       = {10.5067/MODIS/MOD13A3.061}
}

Reference papers¶

Overview of MODIS vegetation index performance (NDVI and EVI definitions, compositing) — DOI 10.1016/S0034-4257(02)00096-2

@article{huete2002modisvi,
  author  = {Huete, A. and Didan, K. and Miura, T. and Rodriguez, E. P. and Gao, X. and Ferreira, L. G.},
  title   = {Overview of the radiometric and biophysical performance of the {MODIS} vegetation indices},
  journal = {Remote Sensing of Environment},
  volume  = {83},
  number  = {1-2},
  pages   = {195--213},
  year    = {2002},
  doi     = {10.1016/S0034-4257(02)00096-2}
}

MOD13 User's Guide (C6.1) — no DOI

@techreport{didan2019mod13ug,
  author      = {Didan, Kamel and Barreto Munoz, Armando},
  title       = {{MODIS} Vegetation Index User's Guide ({MOD13} Series), Version 3.10 (Collection 6.1)},
  institution = {Vegetation Index and Phenology Lab, The University of Arizona},
  year        = {2019},
  url         = {https://lpdaac.usgs.gov/documents/621/MOD13_User_Guide_V61.pdf}
}

Acknowledgements¶

Following the EOSDIS Data Use and Citation Guidance, LP DAAC asks you to cite the DOI of each product you used (by satellite, resolution and period). DOIs follow the pattern 10.5067/MODIS/.061 (e.g. 10.5067/MODIS/MOD13A1.061 for 500 m 16-day, 10.5067/MODIS/MOD13C1.061 for 0.05° 16-day). Cite Huete et al. (2002) for the index definitions and compositing.

Information on the datasets used in this study was compiled with the help of the Korean Climate Data Navigator (KCDN) (Sim, 2026; https://doi.org/10.5281/zenodo.23300923).

Links¶

• MOD13 User's Guide V3.10 (C6.1, PDF)
• Earthdata catalog — MOD13Q1 V061
• Earthdata catalog — MOD13A3 V061
• MODIS/VIIRS land quality known issues (LDOPE)
• MODIS Land Team news (orbit drift, C7 plans)
• LAADS DAAC — MODIS to VIIRS Transition