Phase to Height conversion (InSAR operator)

Phase to Height conversion

This operator converts the unwrapped interferometric phase to the heights in the radar coded system. This functionality is sometimes referred to as "slant-to-height" conversion.

Implementation is performed following the Schwabisch method, that uses polynomials to compare the actual phase with the flat earth (reference) phase.

The Schwabisch method, is a fast method that yields the radar coded heights. It builds on the idea to first compute the reference phase at a number of discrete heights and then to compare the actual phase from the interferogram with these pre-computed values to determine the height.

An obstacle with this method is that the interferograms that are used as input do not contain the reference phase anymore, so that has to be pre-computed and included in the height-estimation procedure.

Operator parameters:

  
  1. Number of estimation points: The number of locations to compute the reference phase at different altitudes.
  2. Number of height samples: Number of height samples in range [0,5000) at which the reference phase will be estimated.
  3. Degree of 1D polynomial: Degree of the one-dimensional polynomial to "fit" the reference phase through.
  4. Degree of 2D polynomial: Degree of the two-dimensional polynomial to fit the reference phase through.
  5. Orbit interpolation degree: Defaults to a polynomial of degree (number of state vectors)-1, but smaller than degree 5.

Source Products:

 

Unwrapped interferometric product.

Output bands:

 

The height estimated from the unwrapped interferogram. The heights are stored meters, while 0.0 height indicates the problem with unwrapping.

Implementation notes:

 

(More details on algorithmic implementation COMING SOON!)