This paper presents a preliminary result of ongoing research on unmanned aerial vehicle (UAV) for cooperative mapping to support a large-scale urban city mapping, in Malang, Indonesia. A small UAV can carry an embedded camera which can continuously take pictures of landscapes. A convenient way of monitoring landscape changes might be through accessing a sequence of images. However, since the camera’s field of view is always smaller than human eye’s field of view, the need to combine aerial pictures into a single mosaic is eminent. Through mosaics, a more complete view of the scene can be accessed and analyzed. A semi-automated generation of mosaics is investigated using a photogrammetric approach, namely a perspective projection which is based on collinearity condition. This paper reviews the general projection model based on collinearity condition and uses that to determine a common projective plane from images. The overlapped points for each RGB channel are interpolated onto that of orthographic plane to generate mosaics. An initial attempt shows a promising result.

A fixed focal length lens (FFL) camera with on-adjustable focal length is common companions for conducting aerial photography using unmanned aerial vehicles (UAVs) due to its superiority on optical quality and wider maximum aperture, lighter weight and smaller sizes. A wide-angle 35mm FFL Sony a5100 camera had been used extensively in our recent aerial photography campaign using UAV. Since this off-the-self digital camera is categorized into a non-metric one, a stability performance issue in terms of intrinsic parameters raises a considerably attention, particularly on variations of the lens principal distance and principal point’s position relative to the camera’s CCD/CMOS sensor caused by the engine and other vibrations during flight data acquisitions. A series of calibration bundle adjustment was conducted to determine variations in the principal distances and principal point coordinates before commencing, during, and after accomplishment of the flight missions. This paper demonstrates the computation of the parameters and presents the resulting parameters for three different epochs. It reveals that there are distinct discrepancies of the principal distances and principal point coordinates prior to, during, and after the mission, that peaked around 1.2mm for the principal distance, as well as around 0.4mm and 1.3mm along the x-axis and the y-axis of the principal point coordinates respectively. In contrast, the lens distortions parameters show practically no perturbations in terms of radial, decentering, and affinity distortion terms during the experiments.

Orthophoto mosaic is assembled from aerial perspective images through a process called orthorectification, which eliminate photographic tilts and terrain relief effects. These orthorectified images have been resampled from the original ones that may have been prepared from a DTM which does not accurately model the surface. Meanwhile, some proprietary software such as Agisoft utilizes spatially dense 3D point clouds that are generated from a so called Structure from Motion technique to generate the orthophoto. The software provides a black-box method to regard these clouds as DSM, and it utilizes this surface model to project pixels from the original images. This paper investigates geometric accuracy of the produced orthophoto mosaic according to the American Society of Photogrammetry and Remote Sensing (ASPRS) standards. To minimize scale differences among images, a 35mm fixed-lens camera is mounted on a fixed-wing UAV platform. Flight missions are carried out at around 250m flying height controlled by a navigational grade sensor on board to provide spatial resolution of about 27mm. A number of orthophoto mosaics are produced by varying numbers of GCPs, flight paths configuration and terrain relief differences. The geometric accuracies are assessed through a provision of ICPs on each test field area. Coordinates deviations between the ICP and the corresponding orthophotos are framed into a RMSE figures. Within a 95% confidence level, it is revealed that a suitable orthophoto map scale is up to around 1:500. It is recommended that a cross flight configuration to achieve better results.

This study aimed to assess the feasibility of using terrestrial laser scanning (TLS) technology for creating 3D asset registries in facilities management. The research utilized a case study approach to scanning an industrial facility, and the resulting data was processed to create a 3D model of the assets. The study found that TLS technology can produce highly accurate and detailed 3D models of assets, which can aid in asset management and maintenance. However, the technology has some limitations, such as cost and the need for skilled operators. The study suggests that TLS technology can be a valuable tool for asset management and recommends further research in this area.

Salah satu kesalahan yang terdapat pada citra satelit dipengaruhi oleh topografi permukaan bumi sedangkan wilayah Indonesia memiliki karakteristik topografi berbeda-beda baik ketinggian maupun kelerengannya, Pada penelitian hasil orthorektifikasi citra satelit resolusi tinggi dilakukan uji akurasi pengaruh penggunaan DEM Nasional terhadap 4 wilayah yang memiliki topografi yang tidak seragam. Hasil uji akurasi tersebut akan dilakukan analisis perbandingan sehingga diketahui pengaruh topografi terhadap hasil orthorektifikasi sebagai proses untuk pembuatan peta dasar skala 1:5000. Orthorektifikasi menggunakan 15 titik GCP tiap wilayah dan 15 titik ICP tiap wilayah yang tersebar dalam AOI. Pada wilayah kota palangka raya menggunkan 2 scene citra terdapat 4 titik GCP di area citra bertampalan mendapatkan hasil RMS masing masing tiap scene 0,42 piksel dan 0,42 piksel, kecamatan Tirtoyudo terdapat 8 titik GCP di area bertampalan mendapatkan hasil RMS 1,07 piksel dan 0,99 piksel , sedangkan kecamatan trenggalek dan kecamatan ngajum hanya memiliki 1 scene citra masing masing mendapat hasil RMS 0,84 piksel dan 1,39 piksel. Perbandingan Uji akurasi hasil orthorektifikasi wilayah kecamatan tirtoyudo yang memiliki kelerengan topografi dominan agak curam, curam, dan sangat curam mendapat nilai CE90% terbesar yaitu 2,1 m masuk pada kelas 2 sebagai syarat uji peta dasar skala 1:5000, nilai uji akurasi terkecil 0,94 m terdapat pada Kota Palangka Raya yang memiliki kelerengan topografi dominan landai dan datar