International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Volume XXXIX-B8, 2012 
XXII ISPRS Congress, 25 August — 01 September 2012, Melbourne, Australia 
In this work we apply a methodology based on the last option to 
monitoring a mobilized mass affecting to a road cut and the 
upslope. The use of ETSR89 —the official reference system that 
are being adopted in Spain for the next years- as stable system 
for the two field campaigns allow carry out a multi-temporal 
study in a reliable way. This procedure, in which the position of 
measurement stations are obtained using GPS, is applied 
because of the unfavorable conditions of the study zone: the 
instability of the whole scanned terrain where not enough wide 
stable zones can be found, the poor or null accessibility making 
impossible the use of targets, a not very adequate geometry 
stations network located in the opposite slope, and a complex 
terrain with a lot of fallen blocks and vegetation. 
The improvement of techniques to TLS data capture and 
processing is the goal of this work. In this paper, we describe a 
methodological approach for referencing terrestrial laser 
scanner data for multi-temporal studies in landslide monitoring. 
Currently, this methodology is being tested with additional 
works based on the integration of different techniques of data 
capture besides TLS: close range photogrammetry, aerial 
photogrammetry with current and historical images and airborne 
LiDAR. 
  
Figure 1. Orthophotograph of the study area in Jaén province 
(Southern Spain). The landslide zone is delimited by dotted red 
line. Positions of scan stations are drawn in yellow. 
2. STUDY AREA AND LANDSLIDE DESCRIPTION 
The studied road cut are located at the South of Jaén province 
(Spain), around and along a section of A-44 national highway 
that connect Granada and Madrid, practically in the provincial 
boundary between Granada and Jaén (figure 1). In fact, 
landslide has been called *La Frontera" (the frontier) because it 
is located opposite to a petrol station near the mentioned 
boundary (figure 1). 
As a consequence of a heavy rainfall in 2009/10 winter, in 
which accumulated precipitations between December and 
March reach more than 400 mm in the region (double of the 
mean annual precipitation to these months) according Spanish 
Weathering Agency (AEM), a lot of terrain instability 
phenomena occurred, affecting to natural and man-made slopes 
in the study zone. 
The landslide corresponds to a complex movement in which 
earth flow component predominates although with a certain 
slide in the upper part where an incipient scarp can be observed 
(small steps of sub-metric size and cracks opening). The flow of 
marly materials with a large amount of water can be observed in 
the front of mobilized mass (the road cut), but the typical 
morphology of a flow with a large tongue is not developed by 
the incipient character of the landslide and the very presence of 
the road cut that limits its evolution. The marly materials, 
present in the cut and the upslope, correspond to a geological 
formation in which marl and chalk terms of Lower Cretaceous 
age alternates, belonging to Middle Subbetic of External Zones 
of Betic Cordilleras. The steep reliefs at background in the 
figure 2 are chalk and dolomites of Jurassic Age, underlaying 
marls. 
The landslide was active during rainy months, practically until 
summer when it was stabilized by the actuation of Civil Works 
Ministry of Spanish Government. The campaigns were carried 
out between 10 and 24 March 2010, a two weeks period, in the 
moment of higher activity of landslide. 
  
Figure 2. Panoramic photograph of studied landslide affecting 
road cut and upslope. The main scarp is inside the red square. 
3. TERRESTRIAL LASER SCANNER SURVEY 
3.1 Data capture 
To analyze the displacement of the unstable mass, two scanning 
campaigns were carried out by means of TLS in a time interval 
of 14 days. The used instrument is an Optech ILRIS 3D long 
range TLS (up to 1500 m). 
As we mentioned before, the number and geometry of the scans 
carried out depends on the needs of covering the whole area and 
using at least 3 scan stations to correct data transference to the 
reference system. So, 9 scans in 3 stations in the first campaign 
and 13 scans in 4 stations in the second campaign have been 
carried out (figure 3). Meanwhile the location of the scan 
stations is related to the following factors: the correct geometry 
to further data transference to global system (points well 
distributed and not located in the same straight line), the 
reduction of shadow zones and the stations accessibility. 
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