The coronavirus disease of 2019 (COVID-19) pandemic is currently a global challenge, with 210 countries, including Indonesia, seeking to minimize its spread. Therefore, this study aims to determine the spatiotemporal spread pattern of this virus in Surabaya using various data on confirmed cases from 28 April to 26 October 2021. It also aims to determine the relationship between pollutant parameters, such as carbon monoxide (CO), nitrogen dioxide (NO₂), sulfur dioxide (SO₂), and ozone (O₃), as well as the government’s high social restrictions policy in Java-Bali. Several methods, such as the weighted mean center, directional distribution, Getis–Ord Gi*, Moran’s I, and geographically weighted regression, were used to identify the spatial spread pattern of the virus. The weighted mean center indicated that the epicenter location of the outbreak moved randomly. The directional distribution demonstrated a decrease of 21 km² at the end of the study phase, which proved that its spread has significantly reduced in Surabaya. Meanwhile, the Getis–Ord Gi* results demonstrated that the eastern and southern parts of the study region were highly infected. Moran’s I demonstrate that COVID-19 cases clustered during the spike. The geographically weighted regression model indicated a number of influence zones in the northeast, northwest, and a few in the southwest parts at the peak of R² 0.55. The relationship between COVID-19 cases and air pollution parameters proved that people living at the outbreak’s center have low pollution levels due to lockdown. Furthermore, the lockdown policy reduced CO, NO₂, SO₂, and O₃. In addition, increase in air pollutants; namely, NO₂, CO, SO₂ and O₃, was recorded after 7 weeks of lockdown implementation (started from 18 August).

There is at least 190 million hectare of Indonesia's land part area that should be mapped in large scale cadaster maps. The completion of cadaster maps up to scale 1/2500 are still an open problems. The very high resolution images with spatial resolution less than 10cm can be a good choice to be able to see a parcel boundary. The use of Unmanned Aerial Vehicle- based remote sensing system can produce aerial photograph with spatial resolution less than 10cm. For keeping UAV-based system low-cost, the system architecture consists of (1) aerial platform from hobby aeromodelling; (2) consumers grade camera sensor; (3) a low-cost GPS logger for ground control survey; (4) an open source structure from motion processing; and (5) an open source GIS software. This system was tested for producing a cadaster base map in a paddy field area at Trimulyo village at Bantul Region. The high resolution image with Ground Sampling Distance up to 7 cm can easily to see a parcel boundary and some of boundary markers. Some of the parcel areas were used for geometric evaluation. The bundle adjustment with 9 Ground Control Points (GCP) shows the error less than 12 cm in all coordinates component. Meanwhile, the percentage of area differences from some parcel samples show less than 5% of differences. In future, the potential use of a GPS kinematic assisted photo flight should be explored in accordance to reduce the need for GCP survey.

Orthophoto maps are believed by mapping communities as a favorable media to generate land parcel boundaries for cadaster survey related projects. However, since burgeoning off-the-shelf cameras mounted on the unmanned aerial vehicle (UAV) are commonly utilized for photographing such boundaries, unreliable and unstable intrinsic parameters of these non-metric cameras impede good quality orthophoto productions. This paper presents an alternative method to measure the boundaries reliably without an existence of the orthophoto. A degraded quality of the orthophoto can be circumvented by our newly proposed method so called direct visual referencing. This method comprises two stages. The first step is to perform on the fly camera calibration to minimize instabilities of the intrinsic components of the non-metric camera. Modifying common and widely known flying paths for aerial photogrammetry mission is enabling a block variant self-calibrating bundle adjustments to proceed. The second step is a digitation process. Carefully selected Premark or prominent features along the boundaries are digitized on arbitrary selected images. These features are then matched to the similar ones onto all available images by performing multi photo geometrically constraint least squares image matching. Final results are 3D coordinates from the multi photos triangulation process. These boundaries coordinates are compared against the GPS-RTK measurements on the field. Deviations of these types of coordinates are around 1 cm. It is obvious that this method meets the precision requirement of the GPS-RTK measurements. Therefore we firmly believed that conducting UAV’s cadastral surveys using direct visual referencing is very promising in the near future.

Since the conceptual design phase, the estimate of airplane life cycle cost (LCC) is carried out to support a decision making process. The LCC consist of research, development, testing, and evaluation cost, where an airplane estimated price (AEP) is a part of this calculation. Furthermore, AEP is employed as a non linear objective funtion for developing a constrained optimization algorthm. Rosen’s gradient projection is applyed in the development of computer program named Cost Analysis implementing object oriented approach on Microsoft Visual C++ 6.0. In order to verify the application, some data of Ourania jet airplane were utilized for carrying out a case study. The result of Cost Analysis shows that the estimated LCC are similar to the reference. Also, the optimization problems can be solved by Rosen’s algorithm less than ten iterations. Keywords:Conceptual aircraft design, Life cycle cost, Object oriented approach, Visual C++

Abstrak Kombinasi kondisi wilayah Indonesia yang berbentuk kepulauan, infrastruktur yang terbatas, kekayaan sumber daya alam, dan kerawanan bencana merupakan tantangan bagi kegiatan penilaian lingkungan. Saat ini, penilaian kawasan dengan teknologi penginderaan jauh (inderaja) masih menjadi pilihan yang efisien. Sehingga perlu dibangun sistem inderaja yang mandiri dengan karakteristik yang sesuai dengan kondisi Indonesia. Riset ini bertujuan untuk menguji sistem inderaja dengan wahana udara tanpa awak (WUTA) untuk penilaian secara cepat perubahan lingkungan pasca kejadian bencana. Fokus penilaian secara cepat dimaksudkan untuk aplikasi respon terhadap kejadian bencana (tahap tanggap darurat), dan melihat perubahan aset obyek buatan manusia.. Citra yang dihasilkan juga harus memiliki resolusi spasial yang tajam (< 25cm) agar mudah menilai obyek buatan manusia. Riset ini telah dicobakan dalam melihat perubahan lingkungan pasca kejadian bencana erupsi Gunung Merapi, dan Bencana Gempa Bumi di Aceh Tengah. Pengalaman dari kedua kasus tersebut menunjukkan bahwa sistem inderaja memanfaatkan WUTA memiliki karakteristik biaya operasional rendah, mudah dijalankan oleh operator lokal, kecepatan perolehan hasil, akurasi yang memadai, dan efektif untuk luasan lebih kecil 5000Ha.