Comparing GPS and SBAS results IREA, INGV-CT, INGV-NA NA
Our reference for precision standard deviation 05 0.5 cm/yr per deformation velocity 1 cm per deformation after Casu et al., 2006.
Napoli Bay (Italy) test case: ERS ENVISAT Ascending Orbit QUAR SANA LICO PRET ARFE BAIA IPPO RITE OSVE ACAE Campi Flegrei BKE1 AGR1 Mt. Vesuvio TERZ ONPI ccm/year /yea < -1 >1
Napoli Bay (Italy) test case Δ: : SAR * : GPS LICO ARFE QUAR IPPO OSVE SANA BKE1 PRET BAIA RITE ACAE AGR1 TERZ ONPI σ = 0.45 cm
Napoli Bay (Italy) test case σ = 1.0 cm Non filtrato σ = 0.45 cm Filtrato
Napoli Bay (Italy) test case Ascending Descending GPS Filt Unfilt Filt Unfilt ACAE 0.44 0.98 0.57 0.74 AGR1 0.40 0.72 0.57 0.72 ARFE 0.46 0.98 0.52 0.85 BAIA 0.62 0.96 0.52 0.88 IPPO 0.56 0.90 0.66 0.74 (cm) LICO 0.51 0.84 0.62 0.79 ONPI 0.49 1.12 0.52 0.75 OSVE 0.71 1.34 0.77 0.86 PRET 054 0.54 087 0.87 064 0.64 098 0.98 QUAR 0.38 0.65 0.43 0.73 Standard Deviation RITE 045 0.45 100 1.00 054 0.54 075 0.75 SANA 0.56 0.86 0.67 0.85 mean 0.51 0.94 0.59 0.80
Napoli Bay (Italy) test case Descending up to 2010 LICO ARFE QUAR IPPO OSVE SANA BKE1 PRET BAIA RITE ACAE AGR1 TERZ ONPI
Ascending Descending GPS Filt Unfilt Filt Unfilt Descending ACAE 0.44 0.98 0.57 0.74 ACAE 1.15 AGR1 040 0.40 072 0.72 057 0.57 072 0.72 AGR1 054 0.54 ARFE 0.46 0.98 0.52 0.85 ARFE 0.48 BAIA 062 0.62 096 0.96 052 0.52 088 0.88 BAIA 047 0.47 IPPO 0.56 0.90 0.66 0.74 IPPO 0.91 LICO 0.51 0.84 0.62 0.79 LICO 0.71 ONPI 0.49 1.12 0.52 0.75 ONPI 0.54 OSVE 0.71 1.34 0.77 0.86 OSVE 0.74 PRET 0.54 0.87 0.64 0.98 PRET 0.64 QUAR 0.38 0.65 0.43 0.73 QUAR 0.56 RITE 0.45 1.00 0.54 0.75 RITE 0.48 SANA 0.56 0.86 0.67 0.85 SANA 0.75 mean 051 0.51 094 0.94 059 0.59 080 0.80 mean 066 0.66
GPS <2008 <2010 ACAE AGR1 0.57 057 0.57 1.15 054 0.54 ARFE BAIA 0.52 0.52 0.48 0.47 IPPO LICO 0.66 0.62 0.91 0.71 ONPI OSVE 0.52 0.77 0.54 0.74 PRET QUAR 0.64 0.43 0.64 0.56 RITE SANA mean 054 0.54 0.67 059 0.59 0.48 0.75 066 0.66
Mt. Etna (Italy) test case: : ERS - ENVISAT Descending < -2 cm/year > 2 Ascending < -2 cm/year > 2
Mt. Etna (Italy) test case RPN PER EMFN EMAL LAM STP EFAR MIL GIA EMEG NUN PDG EMGL CAP ETDF ENIC ESLN
Mt. Etna (Italy) test case σ = 1.0 cm Descending Filtered σ = 1.3 cm Descending Unfiltered EMEG
Mt. Etna (Italy) test case Ascending Filtered σ = 1.0 cm Ascending Unfiltered σ = 1.35 cm EMEG
Mt. Etna (Italy) test case Standard Deviation (cm) Ascending GPS Filt Unfilt EFAR 0.84 1.13 EMAL 1.04 1.19 EMEG 1.07 1.35 EMFN 3.06 3.32 EMGL 113 1.13 134 1.34 ENIC 0.63 0.82 ESLN 1.21 1.67 CAP 4.56 5.14 GIA 3.57 3.40 LAM 2.33 2.60 NUN 2.21 2.22 PDG 181 1.81 186 1.86 RPN5 1.78 1.79 SLN 2.24 2.63 STP 2.65 3.07
Mt. Etna (Italy) test case RPN5
Mt. Etna (Italy) test case
Reference
GPS name SAR GPS scarto [cm] [cm] [cm] EMAL -0.0661 0.0129 0.0790 EMEG 0.00000000 0.00000000 0.00000000 EMFN 0.8755 0.3328-0.5427 EMGL 0.6911 1.1872 0.4961 ENIC N/A -0.0254 N/A EPND 1.7452 N/A N/A ESLN 1.1953 0.1176-1.0776
Conclusions and further developments An extensive comparison of SBAS and GPS deformation measurements has been carried out on several volcanic sites. In general, the SBAS time series accuracy is less than 1cm, in accordance with previous studies. Moreover, the atmospheric artifacts accounts for no more that 5mm. Larger errors are associated with large (with respect to the wavelength) and fast (with respect to the revisit time, i. e., temporal sampling) deformation signals at the same time. This is basically due to Phase Unwrapping errors, caused by an undersampling of the deformation signal in time. Possible solutions to this problem are: Reduce the satellite revisit time; Improve existing phase unwrapping algorithms.