International Journal of Geoinformatics

A Comparative Analysis of Camera Rig Parameters in Photogrammetric Software for Small-Format Oblique Camera System on Unmanned Aerial Vehicle

T. Bannakulpiphat — 2024-03-11

Utilizing small-format oblique camera systems to capture simultaneous nadir and oblique photographs from unmanned aerial vehicles (UAVs) is a common practice in modern photogrammetry. Oblique photographs provide enhanced geometric insights into building side views, terrain morphology, and vegetation, thereby enriching interpretation and classification. However, the design of camera rig parameters and their precise mathematical modeling for small-format oblique camera systems in multi-view processing is essential to ensure accurate representation of the physical camera geometry and results. This study investigates the camera rig parameters of the ‘3DM-V3’ small-format oblique camera system, focusing specifically on the relative relationship between nadir and oblique cameras, within two prominent photogrammetric software: PIX4Dmapper and Agisoft Metashape. The research concludes that optimal parameterization involves fully constrained relative translation parameters (T_X, T_Y, T_Z)_rel for the four oblique cameras, while setting approximate initial estimates as free constrained for relative rotation parameters (R_X, R_Y, R_Z)_rel. This approach aligns with the physical geometry of the camera system and yields a precise camera model, as confirmed through bundle block adjustment (BBA) computations. PIX4Dmapper yields horizontal and vertical root mean square errors (RMSE) of 0.023 m and 0.019 m, respectively, while Agisoft Metashape results in RMSE of 0.018 m and 0.046 m. These RMSE values, considering the ground sample distance and ground control point accuracy, reflect the robustness of the approach. The insights from this research offer valuable guidance for industries, facilitating informed decisions regarding the selection of appropriate software and parameters for small-format oblique camera systems mounted on UAVs, thus ensuring consistency between theoretical models and real-world applications.

Analysis of the Movement Distribution Pattern of Violent Crime in Malaysia's Capital Region-Selangor, Kuala Lumpur, and Putrajaya

A. Ahmad — 2024-03-11

Previous studies of violent crime have been focused on identifying hot spots areas, ignoring crime movement and distribution, particularly violent-related land use on four different time frames. Studies showed that they have used police station boundaries or sectors to detect crime hotspots without considering land use type and the distribution and movement of crime. Understanding the relationship between violent crime and land use allows stakeholders to make informed decisions about land use, urban planning, and community development projects that can help reduce crime and improve overall community safety and quality of life. The aims of this study to investigate the relationship between violent crimes, time and land use in Selangor State, Kuala Lumpur Federal Territory (KLFT) and Putrajaya Federal Territory (PFT) from 2015 to 2020 using Mean Center and Standard Deviational Ellipses (SDE). These methodologies can assist authorities such as the Royal Malaysia Police (RMP) and Local Authority (LA) to identify potential variables leading to the high prevalence of violent crime in specific locations, which can then be used by police and local authorities to collaborate, establish crime prevention initiatives, and more effectively allocate resources. This study considers four-time frames, namely midnight (12:00-6:59 am), morning (7:00-11:59 am), evening (12:00-6:59 pm) and night (7:00-11:59 pm). The main concern in this article is that the SDE and Mean Center are still being investigated for use in studies of violent crime that are related to land use and spatial temporal. The overall Direction Mean Center and SDE at evening time, has the highest area of 128,146,621.17m². All SDEs are within the boundaries of Kuala Lumpur Contingent Police Headquarters (KLCPH) and Selangor Contingent Police Headquarters (SCPH) has been justify in a shape of Figure and Table in this article. However, only District Police Headquarters (DPH) Putrajaya, namely the police station in Presint 11 and 7 are not included in the analysis. Overall, police and local authorities may find it useful to employ SDE and the Mean Center technique to investigate violent crime using land use and spatial-temporal data their efforts to reduce violent crime, enhance public safety, and implement preventative measures in high-crime areas.

Investigating Land Surface Temperature Variation and Land Use Land Cover Changes in Pathumthani, Thailand (1997-2023) using Landsat Satellite Imagery: A Comprehensive Analysis of LST and Urban Hot Spots (UHS)

P. Thammaboribal — 2024-03-11

This study explores the dynamic transformations in land use and land cover (LULC), land surface temperature (LST), and the spatial distribution of Urban Hot Spots (UHSs) in Pathumthani from 1997 to 2023. Landsat satellite imagery was utilized for the analysis, employing the Maximum Likelihood classifier for LULC classification. The research reveals a substantial surge in built-up areas, particularly notable with a twofold increase in 2023 compared to 1997, concentrated along the north-south axis. While vegetation remains the dominant land cover, it experienced an initial increase from 2004 to 2023, followed by a declining trend. Nevertheless, vegetation constitutes over 60% of the total area, concentrated in the eastern and western regions. In summary, the spatial distribution of UHS in 1997 exhibited dispersion across the study area. However, starting from 2004, there was a noticeable concentration of UHSs within built-up areas, particularly in the northern part, coinciding with the presence of the Navanakorn industrial zone. Urban development encroachment into Muang Pathumthani, Thanyaburi, and Lam Luk Ka districts led to the emergence of UHSs in the southern part, mirroring the trajectory of urban sprawl. This southern section, adjacent to Bangkok and in proximity to Don Muang airport, witnessed UHS emergence due to urban expansion, notably influenced by the development of the mass rapid transit (MRT) connecting Pathumtani and Bangkok. The study highlights the importance of studying Land Surface Temperature (LST) to identify areas with higher temperatures, contributing valuable insights for urban planning and strategies to mitigate heat-related challenges in the region.

Exploring the Effects of Land Use/Land Cover (LULC) Modifications and Land Surface Temperature (LST) in Pune, Maharashtra with Anticipated LULC for 2030

A.A. Jagtap — 2024-03-11

Land surface temperature (LST) is a crucial parameter influencing the thermal environment of urban and natural areas. Land use/land cover (LULC) patterns significantly impact LST, highlighting the need for a comprehensive understanding of their relationship. This study delves into the intricate interplay between LULC and LST in Pune city, India, employing a spatiotemporal analysis approach. The study utilizes satellite imagery from 2000, 2010, and 2022 to map LULC changes with Maximum likelihood, support vector machine and Random tree classification and their evaluation with accuracy and Kappa coefficient. Additionally, projected LULC for 2030 is prepared to assess future LST scenarios. Winter and summer LST data are analyzed to capture the seasonal dynamics of LST-LULC interactions. Pune has undergone significant LULC transformations, with the proportion of built-up areas increasing from 7% in 2000 to 47% in 2022, while barren land has decreased from 41% to 37%. Built-up areas exhibit consistently lower LST values during winter, while barren land tends to have the highest LST. In contrast, during summer, built-up and barren areas experience higher LST values, while water bodies and vegetation display relatively lower LST values due to their cooling effects. Mean LST in Pune has increased from 34.59°C in 2000 to 39.38°C in 2022, reflecting the changing thermal dynamics associated with LULC alterations. The expansion of built-up areas has contributed to temperature increases of up to 5.5°C in specific locations, highlighting the urban heat island effect. The study's findings emphasize the need for sustainable land use planning and development strategies to mitigate the adverse impacts of urbanization on LST. Policymakers, urban planners, and environmentalists can utilize these insights to develop informed land use policies, zoning regulations, and climate-smart urban development strategies.

Unmanned Aerial Systems for Building Footprint Extraction in Urban Area

A. Djenaliev — 2024-03-11

The use of Unmanned Aerial Systems (UAS) in remote sensing applications, specifically using the Trimble UX5 HP platform for aerial data collection over Karakol city in Kyrgyzstan. Photogrammetric technique used to identify and match common features in the overlapping aerial images to create a sparse point cloud, which were further processed to create a Digital Surface Model (DSM). A slope-based filtering algorithm was applied to the DSM data for generating a Digital Terrain Model (DTM). The normalized Digital Surface Model (nDSM) was derived from the DSM by subtracting the DTM. Object-based image analysis applied to UAS datasets for the extraction of building footprints in an urban area. The results indicate that extracted building footprints have been generated accurately with an overall completeness of 92.4% and correctness of 95,2%.

Technical and Economic Potential of Solar Energy on Rooftops: A Case Study at Lampang Rajabhat University, Thailand

W. Wongwan — 2024-03-11

This paper presents an assessment of the potential of solar rooftops, and an analysis of the feasibility of investing in rooftop photovoltaic systems for the buildings at Lampang Rajabhat University. The ArcGIS solar radiation analysis tool was used to prepare the solar radiation maps. The derived solar radiation values were then used to evaluate the viability of investing in rooftop photovoltaic (PV) systems, considering factors that included Net Present Value (NPV), Internal Rate of Return (IRR), and Payback Period (PB) through project analysis and evaluation. According to the analysis, 23 buildings could be fitted with a solar rooftop, and 4,106 solar panels would cover 8.29% of the roof area. Southerly oriented pitched roofs had high solar radiation; nevertheless, slopes steeper than 40° reduced the radiation. Flat roofs with solar panels that were oriented southward and inclined at around 15° were found to be effective. When the PV-potential value was compared with the PV output value, a 0.19% difference between the values was observed. After we adjusted the PV-potential value in the PV-potential areas, the solar energy potential was determined to be 1,540,389.14 kWh per year. This potential could result in a 42.73% reduction in the total electricity cost at the university. Furthermore, the system’s financial and environmental analyses revealed that the discounted PB would be 9 years and 6 months, with a reduction of 791.44 tCO₂eq/year. These findings could be used to guide the university in developing a policy about the installation of a rooftop PV system, reduce fossil fuel consumption, and increase self-generated clean energy. These indicators are critical milestones for the university toward becoming a green university and achieving the Sustainable Development Goals

Assessment of Empirical Near-Shore Bathymetry Model Using New Emerged PlanetScope Instrument and Sentinel-2 Data in Coastal Shallow Waters

N. Khakhim — 2024-03-11

Shallow water bathymetric information is important for human life because it has a strong influence on phenomena and dynamics in coastal areas. Conventional bathymetric mapping methods are capable of obtaining high-precision accuracy, but require expensive and complex resources. Specifically, in shallow waters, survey instruments have difficulty obtaining adequate depth data due to the many obstacles that must be overcome. Remote sensing-based shallow water bathymetry called as Satellite-Derived Bathymetry (SDB) is a reasonable and efficient choice. Technological developments enable SDB data processing to be much more efficient in terms of time and storage by utilizing cloud-based platforms such as Google Earth Engine (GEE). Spatial and temporal resolution is still a challenge in SDB, so in this condition PlanetScope with daily temporal resolution capabilities is an optimistic choice. However, this image falls into a relatively new image category. In this study we tested the performance of Sentinel-2A imagery and new PlanetScope imagery bands. The existence of the new sensor owned by PlanetScope allows an increased choice of SDB data sources with high spatial and temporal resolution that is better than the general datasets currently available. There are four additional channels are Coastal Blue, Green I, Yellow, and Red Edge. Assessment is needed to test the capabilities of each new channel using empirical methods via the Stumpf algorithm. Based on accuracy assessment observations, the Sentinel-2A channel combination is still better in terms of accuracy and determination, because it is able to represent the depth in the study area up to 70%. The potential use of PlanetScope's new channels for SDB applications can still be seen in the combination of the Coastal Blue and Yellow channels. This channel combination is still able to represent 47% of the depth variations in the study area.