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Description

The Observational Products for End-Users from Remote Sensing Analysis (OPERA) Land Surface Disturbance Alert from Harmonized Landsat Sentinel-2 (HLS) product Version 1 maps vegetation disturbance alerts that are derived from data collected by Landsat 8 and Landsat 9 Operational Land Imager (OLI) and Sentinel-2A, Sentinel-2B, and Sentinel-2C Multi-Spectral Instrument (MSI). A vegetation disturbance alert is detected at 30 meter (m) spatial resolution when there is an indicated decrease in vegetation cover within an HLS pixel. The Level-3 data product also provides additional information about more general disturbance trends and auxiliary generic disturbance information as determined from the variations of the reflectance through the HLS scenes. HLS data represent the highest temporal frequency data available at medium spatial resolution. The combined observations will provide greater sensitivity to land changes, whether of large magnitude/short duration or small magnitude/long duration.

The OPERA_L3_DIST-ALERT-HLS (or DIST-ALERT) data product is provided in Cloud Optimized GeoTIFF (COG) format, and each layer is distributed as a separate file. There are 19 layers contained within the DIST-ALERT product. The layers for both vegetation and generic disturbance include disturbance status, loss or anomaly, maximum loss anomaly, disturbance confidence layer, date of disturbance, count of observations with loss anomalies, days of ongoing anomalies, and day of last disturbance detection. Additional layers are vegetation cover percent, historical percent vegetation cover, and data mask. See the Product Specification Document (PSD) for a more detailed description of the individual layers provided in the DIST-ALERT product.

The OPERA project is funded by NASA’s Satellite Needs Working Group (SNWG) which provides data products developed to meet the needs of stakeholders from US government agencies.

The OPERA_L3_DIST-ALERT-HLS product contains modified Copernicus Sentinel data (2020-2025).

Known Issues

  • Additional usage constraints are provided under Section 5 of the Algorithm Theoretical Basis Document (ATBD).

Product Summary

Platforms
Sentinel-2A ,
Sentinel-2B ,
Sentinel-2C ,
LANDSAT-8 ,
LANDSAT-9
Instruments
Sentinel-2 MSI ,
OLI
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Spatial Resolution
30 Meters x 30 Meters
Spatial Reference System(s)
UTM
Location
GLOBAL LAND
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2022-01-01 to Present
Temporal Resolution
1 Day
Data Partner
Land Processes Distributed Active Archive Center (LP DAAC) ,
Global Land Disturbance Mapping for JPL OPERA (Observational Products for End-Users from Remote Sensing Analysis), University of Maryland (UMD/GLAD)
Concept ID
C2746980408-LPCLOUD
Data State
ACTIVE
Number of Files/Granules
12719386
Processing Level
3
Published
Science Keywords
Land Use/Land Cover ,
MECHANICAL DISTURBANCE ,
DISTURBANCE

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

Hansen, M. (2024). OPERA Land Surface Disturbance Alert from Harmonized Landsat Sentinel-2 product (Version 1) [Data set]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/SNWG/OPERA_L3_DIST-ALERT-HLS_V1.001 Date Accessed: 2026-02-24

Documents

Variables

The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.

For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
DATA-MASK Mask of pixels the algorithms are applied to in the current HLS scene N/A uint8 N/A 0 to 2 N/A
GEN-ANOM Current generic disturbance anomaly value N/A int16 -1 0 N/A
GEN-ANOM-MAX Generic disturbance maximum anomaly value N/A int16 -1 N/A N/A
GEN-DIST-CONF Generic Disturbance Confidence Layer N/A int16 -1 0 N/A
GEN-DIST-COUNT Number of detected spectral anomalies N/A uint8 255 0 to 254 N/A
GEN-DIST-DATE Date of initial generic disturbance Day int16 N/A 0 N/A
GEN-DIST-DUR Generic disturbance duration Day int16 -1 0 to 366 N/A
GEN-DIST-STATUS Generic disturbance status Class Flag uint8 255 0 to 8 N/A
GEN-LAST-DATE Date of last observation assessed for generic disturbance Day int16 -1 N/A N/A
VEG-ANOM Current vegetation anomaly value Percent uint8 255 0 to 100 N/A
VEG-ANOM-MAX Max vegetation anomaly value Percent uint8 255 0 to 100 N/A
VEG-DIST-CONF Vegetation Disturbance Confidence Layer N/A int16 -1 0 N/A
VEG-DIST-COUNT Number of detected vegetation loss anomalies N/A uint8 255 0 to 254 N/A
VEG-DIST-DATE Date of initial vegetation disturbance Day int16 -1 N/A N/A
VEG-DIST-DUR Vegetation disturbance duration Day int16 N/A 0 to 366 N/A
VEG-DIST-STATUS Vegetation disturbance status Class Flag uint8 255 0 to 8 N/A
VEG-HIST Historical vegetation cover indicator Percent uint8 255 0 to 200 N/A
VEG-IND Current vegetation cover indicator Percent uint8 255 0 to 100 N/A
VEG-LAST-DATE Date of last observation assessed for vegetation disturbance Day int16 -1 N/A N/A
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