Vegetation disturbance status data from the OPERA Land Surface Disturbance Annual from Harmonized Landsat Sentinel-2 product over Canada for the year beginning January 2023.
View full-size imageThe Observational Products for End-Users from Remote Sensing Analysis (OPERA) Land Surface Disturbance Annual from Harmonized Landsat Sentinel-2 (HLS) product Version 1 summarizes the DIST-ALERT data product into an annual vegetation disturbance data product. Vegetation disturbance is mapped when there is an indicated decrease in vegetation cover within an HLS Version 2 pixel. The product also provides auxiliary generic disturbance information as determined from the variations of the reflectance through the DIST-ALERT scenes to provide information about more general disturbance trends. The DIST-ANN product tracks changes at the annual scale, aggregating changes identified in the DIST-ALERT product. Only confirmed disturbances from the associated year are reported together with the date of initial disturbance. As confirmed disturbances are determined using subsequent cloud-free observations to determine if the loss detections persist, the required number of HLS scenes depends on visibility of the target. Due to this dependency, summarizing the DIST-ALERT in the DIST-ANN product will have some latency contingent on the algorithmic calibration and is detailed in the Algorithm Theoretical Basis Document (ATBD).
The OPERA_L3_DIST-ANN-HLS (or DIST-ANN) data product is provided in Cloud Optimized GeoTIFF (COG) format, and each layer is distributed as a separate COG. There are 21 layers contained within the DIST-ANN product: vegetation disturbance status, historical vegetation cover indicator, maximum vegetation cover indicator, maximum vegetation anomaly value, vegetation disturbance confidence layer, date of initial vegetation disturbance, number of detected vegetation loss anomalies, vegetation disturbance duration, date of last observation assessed for vegetation disturbance, and several generic disturbance layers. Each product layer is gridded to the same resolution and tiling system as HLS V2: 30 meter (m) and Military Grid Reference System (MGRS). See the Product Specification Document (PSD) for a more detailed description of the individual layers provided in the DIST-ANN product.
Characteristic | Description |
---|---|
Collection | SNWG OPERA Disturbance |
DOI | 10.5067/SNWG/OPERA_L3_DIST-ANN-HLS_V1.001 |
File Size | ~25 MB |
Temporal Resolution | Yearly |
Temporal Extent | 2022-01-01 to Present |
Spatial Extent | Global (Non-Antarctic) |
Coordinate System | Universal Transverse Mercator (UTM) |
Datum | World Geodetic System (WGS84) |
File Format | Cloud Optimized GeoTIFF (COG) |
Geographic Dimensions | 109.8 km x 109.8 km |
Characteristic | Description |
---|---|
Number of Science Dataset (SDS) Layers | 21 |
Columns/Rows | 3660 x 3660 |
Pixel Size | 30 m |
SDS Name | Description | Units | Data Type | Fill Value | No Data Value | Valid Range | Scale Factor |
---|---|---|---|---|---|---|---|
VEG-DIST-STATUS¹ | Vegetation disturbance status | Class Flag | 8-bit unsigned integer | N/A | 255 | 0,3,6,7,8,9,10 | N/A |
VEG-HIST | Historical vegetation cover indicator | Percent | 8-bit unsigned integer | N/A | 255 | 0 to 100=Vegetation percent; 200=No disturbance | N/A |
VEG-IND-MAX | Maximum vegetation cover indicator | Percent | 8-bit unsigned integer | N/A | 255 | 1 to 100: Estimated percent vegetation | N/A |
VEG-ANOM-MAX | Maximum vegetation anomaly value | Percent | 8-bit unsigned integer | N/A | 255 | 1 to 100: Maximum loss of percent vegetation | N/A |
VEG-DIST-CONF | Vegetation Disturbance Confidence Layer | N/A | 16-bit signed integer | N/A | -1 | 0=No disturbance; >0=Disturbance confidence | N/A |
VEG-DIST-DATE | Date of initial vegetation disturbance | Day | 16-bit signed integer | N/A | -1 | 0: No disturbance; >0: Day of first loss anomaly detection | N/A |
VEG-DIST-COUNT | Number of detected vegetation loss anomalies | N/A | 8-bit unsigned integer | N/A | 255 | 0=No loss anomalies;1 to 254=Count of loss | N/A |
VEG-DIST-DUR | Vegetation disturbance duration | Day | 16-bit signed integer | N/A | -1 | 0 to 366=Number of days from first anomaly to most recent anomaly detection | N/A |
VEG-CONF-PREV | Indicator of vegetation disturbance from previous year | Class Flag | 8-bit unsigned integer | N/A | 255 | 0: No disturbance;1: Confirmed low previous year;2: Confirmed high previous year | N/A |
VEG-CONF-COUNT | Count of confirmed vegetation disturbance events | N/A | 8-bit unsigned integer | N/A | 255 | ≥0: Count of confirmed vegetation disturbance events | N/A |
VEG-IND-3YR-MIN | Minimum three year vegetation cover indicator | Percent | 8-bit unsigned integer | N/A | 255 | 0 to 100: Vegetation percent | N/A |
VEG-LAST-DATE | Date of last observation assessed for vegetation disturbance | Day | 16-bit signed integer | N/A | -1 | 0=Never flagged as land;>0=Day of last land observation | N/A |
GEN-DIST-STATUS² | Generic disturbance status | Class Flag | 8-bit unsigned integer | N/A | 255 | 0,3,6,7,8,9,10 | N/A |
GEN-ANOM-MAX | Generic maximum disturbance anomaly value | N/A | 16-bit signed integer | N/A | -1 | 0=No disturbance; >0= Spectral distance | N/A |
GEN-DIST-CONF | Generic Disturbance Confidence Layer | N/A | 16-bit signed integer | N/A | -1 | 0=No disturbance; >0=Disturbance confidence | N/A |
GEN-DIST-DATE | Date of generic initial disturbance anomaly | Day | 16-bit signed integer | N/A | -1 | 0: No disturbance; >0: Day of first loss anomaly detection | N/A |
GEN-DIST-COUNT | Number of detected spectral anomalies | N/A | 8-bit unsigned integer | N/A | 255 | 0=No loss anomalies;1 to 254=Count of loss anomalies | N/A |
GEN-DIST-DUR | Generic disturbance duration | Day | 16-bit signed integer | N/A | -1 | 0 to 366=Number of days from first anomaly to most recent anomaly detection | N/A |
GEN-CONF-PREV | Indicator of generic disturbance from previous year | Class Flag | 8-bit unsigned integer | N/A | 255 | 0: No disturbance;1:Confirmed low previous year;2:Confirmed high previous year | N/A |
GEN-CONF-COUNT | Count of confirmed generic disturbance events | N/A | 8-bit unsigned integer | N/A | 255 | >0: Count of confirmed generic disturbance alert | N/A |
GEN-LAST-DATE | Date of last observation assessed for generic disturbance | Day | 16-bit signed integer | N/A | -1 | 0=Never flagged as land;>0=Day of last land observation | N/A |
Value | Description |
---|---|
0 | No disturbance |
3 | Confirmed <50% ongoing |
6 | Confirmed ≥50% ongoing |
7 | Confirmed <50% finished |
8 | Confirmed ≥50% finished |
9 | Confirmed previous year <50% |
10 | Confirmed previous year ≥50% |
255 | No data |
Value | Description |
---|---|
0 | No disturbance |
3 | Confirmed low, ongoing |
6 | Confirmed high, ongoing |
7 | Confirmed low, finished |
8 | Confirmed high, finished |
9 | Confirmed low, previous year |
10 | Confirmed high, previous year |
255 | No data |
For more information about raster layers see Table 4-2 in the Product Specification.
Additional usage constraints are provided under Section 5 of the Algorithm Theoretical Basis Document (ATBD).