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Description

The OPERA_L3_DIST-ALERT-HLS Version 0 data product was decommissioned on April 25, 2025. Users are encouraged to use the OPERA_L3_DIST-ALERT-HLS V1 data product which was released on March 14, 2024, and has achieved stage 1 validation.

The Observational Products for End-Users from Remote Sensing Analysis (OPERA) Land Surface Disturbance Alert from Harmonized Landsat Sentinel-2 (HLS) provisional data product Version 0 maps vegetation disturbance alerts 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). 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 product also provides auxiliary generic disturbance information as determined from the variations of the reflectance through the HLS scenes to provide information about more general disturbance trends. 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 in the DIST-ALERT product: vegetation disturbance status, current vegetation cover indicator, current vegetation anomaly value, historical vegetation cover indicator, max vegetation anomaly value, vegetation disturbance confidence layer, date of initial vegetation disturbance, number of detected vegetation loss anomalies, and vegetation disturbance duration. See the Product Specification for a more detailed description of the individual layers provided in the DIST-ALERT product.

Known Issues

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

Version Description

Version 0

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
Geographic Region
GLOBAL LAND
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2022-01-01 to 2024-02-26
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
C2517904291-LPCLOUD
Data State
DEPRECATED
Processing Level
3
Published
Updated
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. (2023). OPERA Land Surface Disturbance Alert from Harmonized Landsat Sentinel-2 provisional product (Version 0) [Data set]. NASA Land Processes Distributed Active Archive Center. https://doi.org/10.5067/SNWG/OPERA_L3_DIST-ALERT-HLS_PROVISIONAL_V0.000 Date Accessed: 2025-10-28

Documents

Variables

Variables are a set of physical properties whose values determine the characteristics or behavior of something. For example, temperature and pressure are variables of the atmosphere. Parameters and variables can be used interchangeably. Variable level attributes provide individual information for each variable.

The Name in this table is the variable name. Fill value indicates missing or undefined data points in a variable. Valid range is the range of values the variable can store. Scale factor is used to increase or decrease the size of an object and can be used to correct for distortion. For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor
GEN-ANOM Spectral anomaly N/A int16 -1 -1 N/A
GEN-ANOM-MAX Maximum spectral anomaly N/A int16 -1 -1 N/A
GEN-DIST-CONF Confidence of generic disturbance, No Data = -1 N/A int16 N/A N/A N/A
GEN-DIST-COUNT Count of observations with spectral anomaly N/A uint8 255 255 to 254 N/A
GEN-DIST-DATE Day of generic disturbance Day int16 -1 -1 N/A
GEN-DIST-DUR Number of days of ongoing spectral anomalies since initial detection Day int16 -1 -1 to 366 N/A
GEN-DIST-STATUS Generic disturbance status Class Flag uint8 255 255 to 4 N/A
GEN-LAST-DATE Day of last land observation for generic disturbance detection Day int16 -1 -1 N/A
LAND-MASK LAND MASK N/A uint8 N/A N/A to 1 N/A
VEG-ANOM Vegetation loss Percent uint8 255 255 to 100 N/A
VEG-ANOM-MAX Maximum vegetation loss anomaly Percent uint8 255 255 to 100 N/A
VEG-DIST-CONF Confidence of vegetation disturbance N/A int16 -1 -1 N/A
VEG-DIST-COUNT Count of observations with vegetation loss N/A uint8 255 255 to 254 N/A
VEG-DIST-DATE Day of vegetation disturbance, No Data = -1 Day int16 -1 -1 N/A
VEG-DIST-DUR Number of days of ongoing loss anomalies since initial detection Day int16 -1 -1 to 366 N/A
VEG-DIST-STATUS Vegetation disturbance status Class Flag uint8 255 255 to 4 N/A
VEG-HIST Vegetation percent of baseline at the time of max anomaly Percent uint8 255 255 to 200 N/A
VEG-IND Vegetation percent Percent uint8 255 255 to 100 N/A
VEG-LAST-DATE Day of last land observation for vegetation disturbance detection Day int16 -1 -1 N/A
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