High-accuracy peat maps are essential for peatland restoration management, but costly, labor-intensive, and require an extensive amount of peat drilling data. This study offers a new method to create an accurate peat depth map while reducing field drilling data up to 75%. Ordinary least square (OLS) adjustments were used to estimate the elevation of the mineral soil surface based on the surrounding soil parameters. Orthophoto and Digital Terrain Models (DTMs) from LiDAR data of Tebing Tinggi Island, Riau, were used to determine morphology, topography, and spatial position parameters to define the DTM and its coefficients. Peat depth prediction models involving 100%, 50%, and 25% of the field points were developed using the OLS computations, and compared against the field survey data. Raster operations in a GIS were used in processing the DTM, to produce peat depth estimations. The results show that the soil map produced from OLS provided peat depth estimations with no significant difference from the field depth data at a mean absolute error of ±1 meter. The use of LiDAR data and the OLS method provides a cost-effective methodology for estimating peat depth and mapping for the purpose of supporting peat restoration.

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Abstract. The digital 3D documentation of architectural heritage using advanced 3D measurement technologies such as UAV photogrammetry and terrestrial LiDAR (TLS) becomes a potential and efficient method since it can produce 3D pointclouds in detail and high density of pointclouds levels. However, TLS is unable to scan the roof part of tall building, whereas UAV photogrammetry achieves high density of pointclouds at that area. In order to make a complete 3D pointclouds of heritage building, we merged and integrated the TLS and UAV pointclouds data by using Iterative Closest Point (ICP) algorithms into one reference system. In this study, we collected two architectural heritage building in Yogyakarta, Indonesia, i.e., "Vredeburg Fort Museum (VFM)" and "Kotagede Great Mosque (KGM)", the oldest mosque in Yogyakarta. For the data acquisition, we used Faro Focus X330 and GLS 2000 Laser Scanner. We produced three-dimensional point clouds from UAV imagery by using Structure from Motion and Multi View Stereo (SfM-MVS) technique through Photoscan software. In order to merging and integrating both of pointclouds data, Maptek I-Site Studio 6.1 with Educational License was used. Those data were successfully registered, and according to the registration report, we had observed 20.60 mm of RMS error. The 3D models and their textures in outdoor and indoor side were processed using Autodesk software. Modelling was carried out on the structure of building’s façade base on simple geometric primitive as planes, straight lines, circles, spheres and cylinder. For interactive visualization, a modern and widely accessible game engine technology (Unity3D) was used. The result was an interactive displaying 3D model of an architectural heritage building in LOD3 level with spatial function for measuring the size and dimension, as well as the area of object. Finally, we created the online version of interactive 3D viewer utilizing WebGL API and Mapbox Unity SDK.

The river is one of the transportation routes for human beings, as well as the pipelines for oil and gas distribution, or as power cable lines and communications networks. In order to not disturb the pipe or cable due to the activity of the ship through the river, it is necessary to study the sediment from the river. This study aims to determine the type of sediment, the thickness of the sediment, the depth of sediment, and volume of the sediment itself. It can be done with acoustic measurements.The measurement of the acoustic survey in this activity uses a sub bottom profiler Strata Box HD type Chirp. By using this tool, it can obtain sediment layer up to a certain depth. The result of the measurement will be interpreted to obtain the travel time of the acoustic wave as it reflected on the sediment layer. The travel time than processed and corrected with the tidal measurement data which made over 14 days to obtain the actual depth value from the result with the sub bottom profiler. The depth data then were quality tested based on reference IHO SP-44 2008 at order 1a.This activity produces a 3D model of river layer, depth profile and sediment layer volume estimation. The result of the quality tested obtained corrected depth data has met the established standards of order 1a IHO SP-44 2008. Using a 95% confidence level, the test results in the first layer is 0.271 m with an error tolerance at 0.510 m. For the second layer has a data quality test results 0.491 m with a tolerance at 0.521 m. The result of depth profile is a long section and cross section. The long section indicates that in the deflection of the river area there is a steep decline compared to the area before and after the river deflection. In addition, the river deflection area has a thinner sedimentary layer. The volume estimation of sediment layers obtained in the area of the activity is 4932752.739 m3.

Multibeam Echosounder (MBES) utilizes acoustic waves emitted to the seafloor through a transmitter or transducer and records its reflective. The information obtained by MBES are depth data and the scattering value of the acoustic signal reflected by the object or the seabed, called backscatter. Acoustic backscatter can be used to classify objects or the seabed such as shipwrecks or seabed sediments. This study focuses on seabed classification using an acoustic backscatter obtained from the measurement at Alur Pelayaran Barat Surabaya (APBS). The data used in this research are acoustic backscatter from bathymetry data extraction and ground truth data of sediments. This study found the fine sand sediments with backscatter value −15.56 dB, and clayey silt sediments with backscatter value −24.36 dB. The correlations between backscatter and seabed sediments in study area were classified into four classes, clay class sediments with backscatter intensity range [(−33.81) – (−28)] dB, clayey silt class sediments with backscatter intensity range [(−27.99) – (−23)] dB, sandy silt backscatter intensity range [(−22.9) – (−18)] dB, and sand class sediments with backscatter intensity range [(−17.99) – (−10)] dB. Based on the results data are known in the study area of seabed conditions dominated by sediments type sandy silt.