| snippet:
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Monthly 12-day coherence average from Sentinel-1 descending track 71 between October 2017 and September 2024. |
| summary:
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Monthly 12-day coherence average from Sentinel-1 descending track 71 between October 2017 and September 2024. |
| extent:
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[[-118.394119309,33.713319848],[-118.343285996,33.764986494]] |
| accessInformation:
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NASA-JPL/Caltech ARIA Team |
| thumbnail:
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thumbnail/thumbnail.png |
| maxScale:
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1.7976931348623157E308 |
| typeKeywords:
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["Data","Service","Map Service","ArcGIS Server"] |
| description:
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<div style='text-align:Left;'><p><span>Researchers working with the Advanced Rapid Imaging and Analysis (ARIA) and Observational Products for End-Users from Remote Sensing Analysis (OPERA) teams at NASA's Jet Propulsion Laboratory, Pasadena, California, created monthly average coherence products for the active landslides in Rancho Palos Verdes, Los Angeles, California, USA.</span></p><p><span>The ARIA/OPERA team computed the interferometric coherence from interferometric synthetic aperture radar (InSAR) data between October 2017 and September 2024. The InSAR data were acquired by Copernicus Sentinel-1A/B satellites on descending (satellite moving south and looking west) track 71 and processed by the ARIA team to geocoded standard unwrapped interferograms (GUNW) with coherence layers. ARIA GUNWs are archived at the NASA Alaska Satellite Facility Distributed Active Archive Center (ASF DAAC).</span></p><p><span>Interferometric coherence is a measure of the correlation or similarity between two satellite acquisition returns over the same area. Coherence values range from 0 to 1, where 0 represents decorrelation (drastic change in ground surface conditions between repeat satellite returns) and 1 represents perfect coherence (high degree of similarity between repeat satellite returns). A significant drop in coherence could be indicative of changes such as vegetation growth, snow cover, and/or surface changes due to rapid ground motion.</span></p><p><span>The </span><a target='_blank'>PV_12DayMonthlyCoherence-2017-2024_S1D64_map.png</a><span> shows the monthly average of 12-day interferometric coherence with a color variation from dark red to white. The red tones indicate lower coherence values indicative of higher surface changes. The white areas show good coherence that could mean either stable or slow moving surface condition. For the landslide, low coherence may also be used in some cases as a proxy for rapid landslide motion. The top row, Average (2015-2022), shows the monthly average between 2015-2022, which may be used as a reference to compare the 2023/2024 monthly averages.</span></p><p><span style='font-weight:bold;'>Processing Details</span></p><p><span>We calculate mean monthly 12 day coherence maps from ARIA Standard InSAR products.</span></p><p><span>We provide mean monthly 12 day coherence maps from ARIA Standard InSAR products for the 2023 water year (October 2022 - September 2023), 2024 water year (October 2022 - September 2023), and monthly coherence values are averaged for years 2017-2022, to compare with values in the 2023 water year and the 2024 water year.</span></p><p><span style='font-weight:bold;'>Files: </span></p><p><span>All files can be downloaded at: </span><a href='https://maps.disasters.nasa.gov/download/gis_products/event_specific/2024/palos_verdes_landslides_202410/opera/coherence/descending/' rel='nofollow ugc' target='_blank'>https://maps.disasters.nasa.gov/download/gis_products/event_specific/2024/palos_verdes_landslides_202410/opera/coherence/descending/</a></p><p><span>PV_Avg12dayCoh_*_S1D71.tif (geotiff) shows the 12-day average coherence for the month/year in the file name.</span></p><p><span>PV_Avg12dayCoh_2017-2022_S1D71.tif (geotiff) shows the 12-day average coherence for the month in the file name averaged between the years 2017 and 2022.</span></p><p><span>PV_12DayMonthlyCoherence-2017-2024_S1D71_map.png shows average monthly 12-day coherence maps draped on lidar hillshade of topography. Landslide boundaries from the California Geological Survey (CGS) and roads and buildings from OpenStreetMap. </span></p><p><span>Released October 28, 2024.</span></p><p><span style='font-weight:bold;'>Data Availability</span></p><p><span>The Sentinel-1 InSAR products produced by ARIA - JPL, contain modified Copernicus data (2024). The products are available to download at </span><a href='https://aria-share.jpl.nasa.gov/20241028-Palos_Verdes_Landslides' rel='nofollow ugc' target='_blank'>https://aria-share.jpl.nasa.gov/20241028-Palos_Verdes_Landslides</a></p><p><span style='font-weight:bold;'>Esri REST Endpoint</span></p><p><span>See URL section on right side of page</span></p><p><span style='font-weight:bold;'>Resolution</span></p><p><span>90 meters</span></p><p><span style='font-weight:bold;'>Credits</span></p><p><span>NASA-JPL/Caltech ARIA Team</span></p><p><span style='font-style:italic;'>Product POCs</span></p><p><span>Alexander L. Handwerger (alexander.handwerger@jpl.nasa.gov)</span></p><p><span>Marin Govorcin (marin.govorcin@jpl.nasa.gov)</span></p><p><span>David Bekaert (david.bekaert@jpl.nasa.gov)</span></p><p><span>Eric Fielding (eric.j.fielding@jpl.nasa.gov)</span></p><p><span style='font-style:italic;'>References/Acknowledge</span></p><p><a href='https://aria.jpl.nasa.gov/' rel='nofollow ugc' target='_blank'>https://aria.jpl.nasa.gov/</a><span> (ARIA project)</span></p><p><a href='https://www.jpl.nasa.gov/go/opera/' rel='nofollow ugc' target='_blank'>https://www.jpl.nasa.gov/go/opera/</a><span> (OPERA Project)</span></p><p><a href='https://github.com/aria-tools/ARIA-tools' rel='nofollow ugc' target='_blank'>https://github.com/aria-tools/ARIA-tools</a><span> (ARIA InSAR data)</span></p><p><a href='https://github.com/insarlab/MintPy' rel='nofollow ugc' target='_blank'>https://github.com/insarlab/MintPy</a><span> (InSAR time series software)</span></p><p><a href='https://opentopography.org/' rel='nofollow ugc' target='_blank'>https://opentopography.org/</a><span> (topographic data)</span></p><p><a href='https://www.openstreetmap.org/' rel='nofollow ugc' target='_blank'>https://www.openstreetmap.org/</a><span> (buildings and road data)</span></p><p><a href='https://www.conservation.ca.gov/cgs/landslides' rel='nofollow ugc' target='_blank'>https://www.conservation.ca.gov/cgs/landslides</a><span> (landslide inventories)</span></p><p><span>ACCESS 19-0023. The InSAR processor was first developed under JPL-Caltech ARIA project.<br /></span></p></div> |
| licenseInfo:
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<DIV STYLE="text-align:Left;"><DIV><P><SPAN>The InSAR products posted here are preliminary results, primarily intended to aid the field response and people who wanted to have a rough first look at the landslide motion. The ARIA-share website has always focused on posting preliminary results as fast as possible for urgent response. All information is provisional for use under emergency response guidelines. These data are provided with absolutely no warranty of any kind. Use at your own risk.</SPAN></P><P><SPAN STYLE="font-weight:bold;">Disclaimer</SPAN></P><P><SPAN>The California Institute of Technology (“Caltech”) makes these data available to the public “as is” for informational purposes only. The methods used and data collected have not been reviewed, cleared, or validated. Caltech, including its operating division the Jet Propulsion Laboratory, its employees, and agents make no representation or warranty, express or implied, as to the merchantability, non-infringement, or fitness for a particular purpose.</SPAN></P></DIV></DIV> |
| catalogPath:
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|
| title:
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ARIA Sentinel-1 (Descending) 12-day Coherence Maps (monthly average) |
| type:
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Map Service |
| url:
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|
| tags:
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["NASA","NASA Disasters Program","ARIA","NASA JPL","Caltech","JAXA","ALOS-2","inSAR","Coherence","Sentinel 1","Copernicus California","USA","Rancho Palos Verdes","CGS"] |
| culture:
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en-US |
| name:
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coherence_descending |
| guid:
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1BD1E08D-7493-4682-AF76-C0A7EC56704F |
| minScale:
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0 |
| spatialReference:
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WGS_1984_Web_Mercator_Auxiliary_Sphere |