Relatively to the Valle d’Aosta region test site, a space-borne analysis, using the DInSAR technique, was done using the ESA’s Grid Processing On-Demand (G-POD) service.

The ASAR-Envisat dataset, available through the Virtual Archive 4 of ESA (by the Category-1A project, part of the ESA Geohazard Supersites initiative), was processed by using the G-POD service. The SAR dataset, made of 38 images acquired from ascending orbit (track 301) between June 2004 and November 2010, has been analyzed with the SBAS-DInSAR technique.

The ASAR-Envisat satellite acquires images characterized by:

- Band acquisition: C Band

- Wavelength (cm): 5.6

- Incident angle (°): 23°

- Azimuth/ground range resolution (m): ≈ 4/20

- Revisit time (days): 35

- Life status: 2002 – 2010

- Space agency: ESA

Regarding the G-POD threshold setting of the SBAS processing, the following parameters were used:

- Max Perpendicular Baseline (m): 400

- Max Temporal Baseline (days): 1500

- Ground Pixel Dimension (m): 40

- Coherence Threshold: 0.8

- Area of Interest (AOI): entire frame

- REF point: Lat. 45.737049 – Lon. 7.31899

The achieved SBAS measurements are provided in geocoded coordinates (Lat./Lon. and UTM WGS84), and are reported in an ASCII file.

The SBAS results, relevant to the entire frame (normally around 100x100 km), have an accuracy of 1 mm/yr concerning the mean velocity measurements, and 5 mm for the deformation measurements [Casu et al., 2006]