REMOTE MONITORING OF A LANDSLIDE USING AN INTEGRATION OF GB-INSAR 
AND LIDAR TECHNIQUES 
A. Lingua a , D. Piatti a , F. Rinaudo a 
a Politecnico di Torino, DITAG, 10129 Corso Duca degli Abruzzi 24, Torino, Italy - (andrea.lingua, dario.piatti, 
fulvio.rinaudo) @polito.it 
Commission I, WG 1/2 
KEY WORDS: Environment, Hazards, Integration, Monitoring, SAR, Terrestrial, LIDAR 
ABSTRACT: 
Landslide monitoring activities are of paramount importance for landslide hazard and risk assessment. They allow predictions to be 
made of the phenomenon evolution which can be used to define risk scenarios, especially when urban areas and infrastructures are 
involved. Over the last decades, spacebome and, more recently, ground-based interferometric synthetic aperture radar (GB-InSAR) 
have been successfully used to identify and classify landslides. Ground-based synthetic aperture radar (GB-SAR) interferometry has 
already been recognized as a powerful tool, that can be considered complementary or alternative to spacebome SAR interferometry 
for terrain monitoring and to detect structural changes in buildings. 
Terrestrial laser scanning (TLS) is a technique increasingly used in remote sensing of unstable slopes. Detailed digital models of the 
observed surface are generated with centimetric resolution. In particular, if multitemporal scans of the same area are performed, these 
scans can be compared in order to obtain displacement fields. 
Both GB-SAR and TLS observations were planned at the end of July 2007 and at the end of October 2007 in order to assess the 
hazard of a quarry that is subject to ground instabilities (the Ex-Locatelli quarry near the Baveno village in the Italian Alps on Lake 
Maggiore). This paper reports on these measurement campaigns and on a test site set up in Florence (Italy) and discusses the 
advantages of the combined use of these innovative techniques. The availability of radar and laser data at the same time has allowed 
a comparison to be made of the two techniques and has provided an effective validation test for both. 
1. CASE STUDY: THE EX-LOCATELLI QUARRY 
LANDSLIDE 
The Ex-Locatelli quarry is located near the Baveno village in 
the Italian Alps on Lake Maggiore. Its mining activities have 
currently been suspended because of many ground instabilities 
that occurred in the past. The main instabilities occurred during 
intense and long precipitations and were characterised by debris 
flows and rock-falls. Because of these instabilities the landslide 
crown withdrew by about 160 m between 1996 and 2005. The 
rocky landslide can be considered quiescent but there is a risk 
of reactivation (Fig. 1). 
Figure 1. The landslide in the Ex-Locatelly quarry 
The fractured area extends from an elevation of 735 m a.s.l. at 
the crown down to 525 m a.s.l. at the toe. Its total length is 
approximately 280-300 m and its maximum width is about 70 
m. 
The area is characterised by complex geological and structural 
features (Crosta et al, 2007). 
The Verbano Cusio Ossola Province Authorities decided to 
monitor the area to understand the entity of movements and 
their spatial distribution. This can easily be done using GB- 
InSAR and TLS measurements. 
2. MEASUREMENT CAMPAIGN 
2.1 GB-SAR measurements 
The employed ground-based radar instrumentation consists of a 
CW-SF (continuous-wave step-frequency) transceiver unit 
(Vector Network Analyzer HP 8753D) working at C-band, a 
linear horizontal rail of about 2 m where the antennas move to 
scan the synthetic aperture, and a personal computer to control 
the VNA, the motion of the antennas, the data recording and all 
the other operations necessary to carry out the measurement 
session. The employed ground-based radar instrumentation was 
designed and realized by the Department of Electronics and 
Telecommunications at the University of Florence, with the 
support of IDS-Ingegneria dei Sistemi SpA Pisa. 
The radar instrumentation was installed at an elevation of 338 m 
a.s.l., on a suitably built platform made on a stable concrete 
building belonging to the Municipality of Baveno, to ensure 
good visibility of the landslide (Fig. 2). The medium distance 
between the GB-SAR instrument and the landslide was about 
600 m. 
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