Kacper Petrykowski, Today at 2:05 PM
L0 Data- represents the raw echos that InSAR sensors receive. This is rarely ever used and all satellite monitoring firms related to monitoring landslides do not have the ability to process this data.
L1 Data- is called single look, or complex SLC (satellite acquisition). Satellite monitoring firms use this data typically provided by the InSAR satellite owners.
Coregistration – Typically you will use amplitude data to match SLC images. DEMs are typically used with simulated amplitudes. DEMs are used because they have a certain relational understanding by the user. The reference coordinate system of a DEM is projected onto the radar’s coordinate system.
This link goes into these further
We use a similar method provided by this link in regards to the coregistration problem. There are two free sources described in the link NED and SRTM. Accurate DEM can be game-changing in InSAR thus a highly prized technology but still expensive to implement.
We use some proprietary and 3rd-party software methods with our work that we would rather not disclose on a public blog for competitive reasons, yet we still do the bulk of our work using freely available software too which we recommend all users in the space to use as well.
We criticize Sattelite monitoring firms that claim mm accuracy for a number of reasons such as atmospheric noise, rain shadow, etc. Additionally, the fact that data is downloaded from a satellite some smoothing has been done with a primitive algorithm. Also, researchers have developed a lot of the code in the InSAR space which is negative because often it has its own bugs and can lead to errors. A lot of this code has not ever been maintained or improved since it was first written.