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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Low-Cost Integrated GNSS/INS for Surface Variation Monitoring Miguel Cordeiro Joo Apolinrio

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 High rates of coastal line retreat. Coastal Erosion Monitoring (1/3) 2

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Effective human occupation in stretches of coastline with great vulnerability to erosive phenomena. Coastal Erosion Monitoring (2/3) 3

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Such phenomena originates potential risk situations; That is why it is extremely important to accurately monitor beach volumetric variations and assess coastal erosion. Coastal Erosion Monitoring (3/3) 4

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Classical Methods to Address the Problem 5

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Very Expensive; Governmental requirements, such as licenses, environmental and safety issues. Terrestrial and Airborne LiDAR 6

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Total Stations Highly Time-Consuming 7

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Mobile Mapping Systems (MMS) The use of laser scanners makes it expensive; Same Government requirements as LiDAR. 8

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Developed Low-Cost Solution 9

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Trolley + GNSS + Tablet 10

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Methodology 11

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Acquisition Device Integrated system developed to collect GNSS data and attitude angles simultaneously; Simple storage and portability. 12

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Antenna Corrections Difficult to guarantee the verticality of antenna mast; Correct acquired data using antenna attitude. 13

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Air2Ground Application developed and implemented in C# to correct the coordinates of the acquired data. Inputs Initial Time offset; Height of the mast; Mast distance to the ground; Antenna coordinates in the IPad reference frame; Two text files (from the GNSS data processing software and from the Tablet). Outputs Point ID; Time of observation; Pitch, Roll, Yaw; X,Y,Z corrected coordinates. 14

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Surface Computation With the corrected positions, we will be able to generate a three-dimensional surface estimated using interpolation techniques 15

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Surface Computation Finally, repeating the process at different times it will be possible to study the coastal line evolution in a time frame. 16 Repeat!!

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Progress Report Conducting experiments in an irregular terrain; Testing C# application to guarantee that the corrections are right; In process to generate a 3D surface of the tested area. 17

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FIG Young Surveyors 2013, Lisbon, 18 October 2013 Thank you for your attention! 18