Step 1: Baseline Estimation

The initial pair of SAR images in slc format is given as input and some field information about the track is filled in by the program.

Particular attention should be paid to the value of the standard baseline relative to the critical baseline. It should be the most normal less than or equal to half of the critical one.

Step 2: Interferogram Generation → without DEM

Insert the original pair of SAR image in slc format. The program associates the two images and outputs as a pwr format and the associated interferogam in int format

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Step 3: Interferogram flattening → DEM / Ellipsoidal

Insert the pair of associated images resulting from the previous step in pwr format as well as the int format. Optional DEM and GCP files are requested. The second is formed as follows:


From the SARscape menu, select Tools → Generate ground control point file. Note the following:

1. The point selection is made in the master image of the pair of associated .pwr images.

2. SPOT image 5m is available for point coordinates (or any other optical image).

3. Point coordinates were calculated in UTM to match the available geographic systems of SARscape.

4. The altitude of the points given is calculated from the sea surface.

5. At least seven points should be selected in total.


After importing the GCP file and determining the Cartographic System (Global UTM) the program calculates the new flattened interferogram in a dint file.

Step 4: Adaptive filter and coherence generation → Adaptive window

The flattened interferogram that occurred in the previous step and the pair of associated images are inserted. The program filters the interferogram to reduce noise and calculates new filtered interferogram (fint file), coherence of image (cc file), and filtered intensity of the combination of images.

Step 6: Orbital Refinement

We give the pair of associated images, synthetic and unfrapped phases, and the GCP file. Optionally, a DEM file can be imported. Also, the UTM cartographic system is defined. This process has no effect but is mandatory to move on to the next steps.

Step 7: Phase to height conversion and Geocoding

The pair of associated images, the synthetic and unfrapped phase and the GCP file are requested, and the following are calculated: DEM file (UTM), geocoded coherence (.cc_geo), estimated data quality, and data analysis based on the local angle incidence.

Written by

I'm a Remote Sensing and a Surveying Engineer. I received my degree from NTUA in 2010, where I also received my Ph.D. in hyperspectral remote sensing in 2016. From graduation in 2010, my career started as a Researcher Associate and Teaching Associate in the Laboratory of Remote Sensing of NTUA. From that time I also worked at several private companies as a Remote Sensing Expert and Geospatial Analyst. From the beginning of 2015 I was positioned as Senior Earth Observation Expert. During these years, I have participated in more than 20 funded European Commission and European Space Agency projects, have over 16 peer reviewed scientific publications in the field of Remote Sensing, and have an international patent in hyperspectral data compression.My main research and professional interests are in the optical remote sensing area, where I specialize in data (images, point measurements) processing and algorithm design and development. Some of the software tools that I operate to accomplish my research and business dreams are SNAP, ENVI, IDL, QGIS, ERDAS Imagine, ArcGIS, and Python. I have been working with these tools since 2008.

Dimitris Sykas

Remote Sensing Expert

Dimitris Sykas