NISAR Beta Geocoded Unwrapped Interferogram Product

Beta geocoded unwrapped interferogram products from the NASA-ISRO Synthetic Aperture Radar (NISAR) mission, derived from Level 2 data. The products contain multiple data layers, including unwrapped phase, coherence magnitude, and ionospheric phase screens, projected onto a geographical grid at 80-meter and 20-meter postings. These products are provided by the Alaska Satellite Facility (ASF) for user familiarization and are not intended for scientific research.

Use Cases

• Analyze ground deformation by interpreting the unwrapped interferometric phase layer in radians.
• Assess data quality and coherence for specific regions using the normalized interferometric coherence magnitude layer at 20 m and 80 m posting.
• Model atmospheric effects by examining the included ionospheric phase screen layer and its associated uncertainty layer.
• Perform pixel-level correlation analysis using the sub-pixel offset layers obtained from incoherent cross-correlation.
• Apply external geophysical corrections using the geocoded lookup tables for phases like solid Earth tides and tropospheric delays.

Strengths

• Contains multiple derived data layers (e.g., unwrapped phase, coherence, ionospheric screen) in a single product.
• Data is geocoded onto a standardized UTM or polar stereographic projection grid for direct geographical analysis.
• Includes high-resolution data layers with postings as fine as 20 meters for the wrapped complex interferogram.

Limitations

• Products are explicitly labeled as Beta, intended for user familiarization and not for scientific research.
• Specific spatial coverage, temporal range, and total volume of the dataset are not provided in the description.
• The continuity of spectral bands may be impacted during mode transitions, affecting ionospheric phase estimates.

Provenance

Source

NASA-ISRO Synthetic Aperture Radar (NISAR) mission, processed and distributed by the Alaska Satellite Facility (ASF).

Collection Method

Derived from Level 2 Range Doppler Wrapped Interferogram (RIFG) and Unwrapped Interferogram (RUNW) products, geocoded using orbit data and a Digital Elevation Model (DEM).

Geography

Global coverage, projected onto Universal Transverse Mercator (UTM) or Polar stereographic grids.