VLM Product Suite

The OPERA Level-4 Vertical Land Motion (VLM) product maps vertical and horizontal (in certain places)* ground motion. It builds on OPERA’s Level-3 Surface Displacement (DISP) and Calibration for Displacement (CAL) products (see description below) to convert relative radar line-of-sight (LOS) measurements into vertical and horizontal ground motion within a common geodetic reference frame.

The CAL product serves as a key intermediate step; it connects the DISP data to a geodetic reference frame using information from GNSS, tectonic plate motion and Glacial Isostatic Adjustment models. Once DISP products are calibrated with CAL, line-of-sight surface motion is converted into vertical and horizontal components to create the final VLM product.

Separate VLM products are generated from Sentinel-1 and NISAR observations: VLM-S1 and VLM-NI, respectively. All products are provided as cloud-optimized, tile-based datasets on the Military Grid Reference System (MGRS) with a nominal 120-meter resolution. These datasets enable consistent, high-resolution monitoring of land motion across local to regional scales, capturing processes such as subsidence, tectonic uplift, volcanic deformation, and groundwater-related surface change, and supporting applications from improved models of coastal flooding and relative sea-level projections to infrastructure resilience.

All VLM products will be accessible through the Alaska Satellite Facility Distributed Active Archive Center (ASF DAAC).

_{*VLM can resolve horizontal ground motion in areas that have DISP products from ascending and descending satellite orbits.}

To contact us or give feedback: opera.sep@jpl.nasa.gov