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Arief R.,Indonesian National Institute of Aeronautics and Space LAPAN | Sudiana D.,University of Indonesia | Ramli K.,University of Indonesia
IOP Conference Series: Earth and Environmental Science | Year: 2017

Synthetic Aperture Radar (SAR) technology is capable to provide high resolution image data of earth surfaces from a moving vehicle. This causes large volumes of raw data. Many researchs were proposed about compressed radar imaging, which can reduce the sampling rate of the analog digital converter (ADC) on the receiver and eliminate the need of match filter on the radar receiver. Besides the advantages, there is a major problem that produces a large measurement matrix, which causes a very intensive matrix calculation. In this paper is studied a new approach to partial acquisition technique to reduce the amount of raw data using compressed sampling in both the azimuth and range and to reduce the computational load. The results showed that the reconstruction of SAR image using partial acquisition model has good resolution comparable to the conventional method (Range Doppler Algorithm). On a target of a ship, that represents a low level sparsity, a good reconstruction image could be achieved from a fewer number measurement. The method can speed up the computation time by a factor of 2.64 to 4.49 times faster than with a full acquisition matrix. © Published under licence by IOP Publishing Ltd.

Ma'Rufah U.,Bogor Agricultural University | Hidayat R.,Bogor Agricultural University | Prasasti I.,Indonesian National Institute of Aeronautics and Space LAPAN
IOP Conference Series: Earth and Environmental Science | Year: 2017

Agricultural drought is closely related to meteorological drought in which the agricultural drought is an impact of meteorological drought. This study aim to understand the duration, spatial extent, severity and lag time of meteorological and agricultural drought during El Niño years. The data used in this study are monthly data of CHIPRS and MODIS. Meteorological drought and agricultural drought are intensified in the El Niño years. The duration of meteorological drought is different in each region but generally occurs during June to November. Agricultural drought mostly occurs from August to November. Spatially, meteorological drought and agricultural drought in 2015 has wider extent and higher severity (SPI <-2 and VHI <10) than in 2002. Agricultural drought generally intensified in areas that have monsoonal rainfall type such as Java, Bali, Nusa Tenggara, Lampung, southern part of Kalimantan, and southern part of Sulawesi. We found that VHI is significantly correlated with SPI-3 reach 58% of the total area of Indonesia. It means rainfall deficit during three months has a significant impact on agricultural drought in Indonesia. In general, SPI-3 and VHI clearly explain the relationship between meteorological drought and agricultural drought in Indonesia. © Published under licence by IOP Publishing Ltd.

Rachim E.,Indonesian National Institute of Aeronautics and Space LAPAN | Tahir A.M.,Indonesian National Institute of Aeronautics and Space LAPAN | Herawan A.,Indonesian National Institute of Aeronautics and Space LAPAN
IOP Conference Series: Earth and Environmental Science | Year: 2017

The development of micro satellites for the last two decades is emerging rapidly as the need of satellite communication usage is increasing. Earth observation is one of the example of how satellites are on demand. Most observation satellites consist of sensors and imaging system on-board. One of the key element to have a good imaging system is a special optical lens system design. Such lens is designed specifically by calculating every parameter such as refractive, reflective indexes, type of surface, distance and many more. Manufactured lenses sometimes do not match the requirement of an imager system hence the special lens design is needed. This paper will first briefly describe the history of optic, theory related to lens system, then the design and the analysis of lens system for micro-satellites generally and LAPAN A4 particularly. © Published under licence by IOP Publishing Ltd.

Irwanto H.Y.,Indonesian National Institute of Aeronautics and Space LAPAN
Proceeding - 2016 International Seminar on Intelligent Technology and Its Application, ISITIA 2016: Recent Trends in Intelligent Computational Technologies for Sustainable Energy | Year: 2016

Development of auto pilot system for high-speed UAV, RKX-200TJ, started in 2013. Currently, as the guided and control system for UAV, the FPGA (Field Programmable Gate Array), in order to flexibility in management of inputs and outputs facilitate many modules, which are processed simultaneously. So the control and stability of the UAV is improved and easy to handle by the processor. Testing on this controller capacity in receiving 4 different inputs and 2 outputs module should be done in an integrated simulation with flight simulator (XPlane) to make sure that all programs run according to plan. Moreover, in this research, HILS (Hardware in the Loop Simulation) is activated to initiate IMU (inertial measurement unit), which is located on top of hexapod to illustrate the close loop programming (PID) between the vehicle attitude, which is seen in hexapod movement and IMU issuing sensor data and received by processor. Integrated development of HILS involves three computer units, i.e. dynamic computer (XPlane), monitoring computer (to control hexapod and to serve as GCS/Ground Control System) and a computer controller that is connected with the main onboard computer (NI MyRIO). All three computers are connected with the UDP (User Datagram Protocol). Meanwhile, the controller computer accesses the main board computer using the facility of 'shared memory'. With these connections, the flying simulation of RKX-200TJ can run smoothly without interruption of time lag. Vehicle simulation models created in XPlane Maker. Vehicle dimensions, engine specification, control geometry and setting of weight and balance are very influential in this simulation. The vehicle model should be made as similar as possible to the actual vehicle. It should include data input of real measurement of the center of gravity (CG), with both X axis and Z axis should be used as a reference model of the vehicle. In this simulation the booster rocket is modeled in JATO (Jet Assisted Take Off) with the firing angle leads to CG, according to the result of real measurement. Simulation of auto take off and auto pilot system went well; describing RKX-200TJ hovered early with booster for 1 sec, and was subsequently taken over by the auto pilot system. The takeover happened when the vehicle speed had reached 250 km/h or 600 m altitude based on the program installed. The auto pilot system would maneuver with a maximum of 30 deg banking and stabilization that maintained speed and altitude to reach the target way point. © 2016 IEEE.

Yulianto F.,Indonesian National Institute of Aeronautics and Space LAPAN | Sofan P.,Indonesian National Institute of Aeronautics and Space LAPAN | Khomarudin M.R.,Indonesian National Institute of Aeronautics and Space LAPAN | Haidar M.,National Coordinating Agency for Surveys and Mapping BAKOSURTANAL
Natural Hazards | Year: 2013

This research focuses on providing information related to the damaging effects of the 2010 eruption of Merapi volcano in Central Java, Indonesia. This information will be used to help emergency responders to assess losses more timely and efficiently, and to monitor the progress in emergency response and recovery. The objectives of this research are: (a) to generate a map of pyroclastic deposits based on activities pre- and post-volcano eruption of 2010 in the research area, (b) to investigate the impact of volcano eruption on the environment, and (c) to assess the impact of volcano eruption on landuse. ALOS PALSAR remote sensing data pre- and post-disaster were used in this research for mapping the volcano eruption. Topographic and geomorphological maps were analyzed for profiling and field orientation, which were used to investigate the impact of volcano eruption on the environment. SPOT 4 satellite images were used in this research for updating landuse information from the topographic map. The result of the landuse updated data was used for assessment of the volcano eruption's impact on landuse with the GIS raster environment. The volcanic eruption that occurred in 2010 is estimated to have an impact of 133. 31 ha for settlements, 92. 32 ha for paddy fields, 235. 60 ha for dry farming, 570. 98 ha for plantations, 380. 86 ha for bare land, and 0. 12 ha for forest areas. An estimate of the number of buildings damaged due to the volcano eruption in 2010 was carried out by overlaying a map of pyroclastic deposits and the information point of the building sites from the topographic map. The total number of buildings damaged is estimated to be around 12,276 units. © 2012 Springer Science+Business Media Dordrecht.

Hamzah R.,Indonesian National Institute of Aeronautics and Space LAPAN | Budhiman S.,Indonesian National Institute of Aeronautics and Space LAPAN
ACRS 2015 - 36th Asian Conference on Remote Sensing: Fostering Resilient Growth in Asia, Proceedings | Year: 2015

In the north coast of Java island there are many small groups of coastal fishermen, who don't have a luxury to have information such as Sea Surface Temperature (SST) and potential fishing zone. Their operational cost inreased because have to look around and spent some extra fuel to search for the presence of fish. SST as a parameter for potential fishing zone can be obtained from the calculation of the thermal band LANDSAT 8. SST was then used as the primary input in thermal front detection using Single Image Edge Detection (SIED) method (1992, Cayula and Cornillon). SIED method has been implemented using low-resolution satellite imagery for Indonesian waters including Suomi National Polar-orbiting Partnership (NPP) with sensor Visible/Infrared Imager and Radiometer Suite (VIIRS). The purpose of this study is to know the movement of thermal fronts in coastal areas. So that the coastal fishermen who gone fishing for only one day can get the potential fishing zone information periodically and reduce their operational cost for daily fishing efficiently. Besides that for increasing the spatial resolution from Potential Fishing Zone (PFZ) information becomes more detailed and specific for particular region which having coastal fishermen.

Julzarika A.,Indonesian National Institute of Aeronautics and Space LAPAN
ACRS 2015 - 36th Asian Conference on Remote Sensing: Fostering Resilient Growth in Asia, Proceedings | Year: 2015

The scarcity of height models is one of the important issues in Indonesia. X SAR, SRTM C, and Aster GDEM are free available global height models. ALOS Palsar height model is the low cost data. Four data can be integrated the height models. Integration takes advantage of each characteristic data. The spatial resolution uses ALOS Palsar. Aster GDEM have minimal height error in the lowland but requires a high pass filter on the plateau or highland. SAR has the advantages of minimal error in the plateau or highland and need a low pass filter on the lowland. DSM uses X-SAR. Characteristics and penetration to vegetation objets can be seen from the wavelength type of SAR data. The aim of this study is to make integration of height models in order to get the vertical accuracy better than vertical accuracy of global height models and minimum height error. The study area is located in Tabalong, South Kalimantan. The first process is to crop the height models data into 50 km2 area. Then, the next process is geoid undulation correction. It uses EGM 2008 for the correction. then geoid undulation correction used with EGM 2008. The next step is to detect the pits and spires by using radius value 1000 m and depth +2σ (+5 m) with uncertainty 95,45%. The next process is to generate HEM and to display the height error of the height model. If four height models data have been completed and height error has been corrected, the next process is to integrate the height models. This integration use 11 scenario of height model combination. To know the accuracy of the 11 integration height model, 80 reference point measured using GNSS and similar point observed on the integration height model are selected. The accuracy test covers RMSE, accuracy (z), and the height difference test. The result of this study shows that the combination of the SRTM C-ALOS Palsar is an optimal height model integration with a vertical accuracy in 1.32 m. In addition, the combination of X-SAR-SRTM C-ALOS Palsar is the second best combination. This combination has a vertical accuracy of 1.96 m. Integration of height models can be used for mapping scale 1: 25000-1: 50000.

Setiyoko A.,Indonesian National Institute of Aeronautics and Space LAPAN
34th Asian Conference on Remote Sensing 2013, ACRS 2013 | Year: 2013

Spatial interpolation is the estimation the value of properties at unsampled sites within the area covered by existing observations. In all the different techniques of DEM (digital elevation model) generation; accuracy of generated DEM is dependent also on spatial interpolation techniques. In this research work, the study and analysis of DEM interpolation techniques are conducted. The middle resolution satellite that has capability in acquisition of stereo images through across the track is IRS-1C. In this project, point map contained height information were generated from IRS-1C PAN stereo data and from geodetic single frequency GPS in differential mode. Different interpolation techniques were applied on these data sets with different combination within these data sets. The interpolation techniques were applied in this research are: IDW, global polynomial, local polynomial, RBF, ordinary kriging, simple kriging, universal kriging, disjunctive kriging, ordinary cokriging, simple cokriging, universal cokriging, disjunctive cokriging. The accuracy of generated DEMs through different interpolation techniques were evaluated with ground point data collected from geodetic single frequency GPS in differential mode. Based on interpolation methods that have been used in this work, kriging interpolation techniques gave less error than other interpolation techniques. The range error of IRS-1C DEMs are between 26.28 m to 40.17 m. Interpolation method with the least error is universal kriging and interpolation method with the highest error is global polynomial. This work shows level of confidence which interpolation techniques can generate better-interpolated continuous surface.

Candra D.S.,Indonesian National Institute of Aeronautics and Space LAPAN
34th Asian Conference on Remote Sensing 2013, ACRS 2013 | Year: 2013

Image fusion is a process to generate higher spatial resolution multispectral images by the fusion of lower resolution multispectral images and higher resolution panchromatic images. It is used to generate not only visually appealing images but also provide detailed images to support applications in remote sensing field, including agriculture. The aim of this study is to evaluate the performance of SPOT-6 data fusion using Gram-Schmidt Spectral Sharpening (GS) method on agriculture land. Comparing GS method with Principle Component Spectral Sharpening (PC) method was done to evaluate the reliability of GS method. In this study, the performance of GS is presented based on multispectral and panchromatic of SPOT-6 image. The spatial resolution of the multispectral (MS) image is enhanced by merging the high resolution Panchromatic (Pan) image in GS method. The fused image of GS and PC were assessed visually and stastically. Relative Mean Difference (RMD), Relative Variation Difference (RVD), and Peak Signal to Noise Ratio (PSNR) Index were used to assess the fused image statistically. The test sites of agriculture land devided into four main areas i.e. whole area, rice field area, forest area and settlement. Based on the results, the visual quality of the fused image using GS method is better than using PC method. The color of the fused image using GS is better and more natural than using PC. In the statistical assessment, the RMD results of both methods are similar. In the RVD results, GS method is better then PC method especially in band 1 and band 3. GS method is better than PC method in PSNR result for each test site. It is observed that the Gram-Schmidt method provides the best performance for each band and test site. Thus, GS is robust method for SPOT-6 data fusion especially on agriculture land.

Yulianto F.,Indonesian National Institute of Aeronautics and Space LAPAN | Suwarsono,Indonesian National Institute of Aeronautics and Space LAPAN | Sofan P.,Indonesian National Institute of Aeronautics and Space LAPAN
Pure and Applied Geophysics | Year: 2016

In this research, remotely sensed data has been used to estimate the volume of pyroclastic deposits and analyze morphological changes that have resulted from the eruption of Sinabung volcano. Topographic information was obtained from these data and used for rapid mapping to assist in the emergency response. Topographic information and change analyses (pre- and syn- eruption) were conducted using digital elevation models (DEMs) for the period 2010–2015. Advanced spaceborne thermal emission and reflection radiometer (ASTER) global digital elevation model (GDEM) data from 2009 were used to generate the initial DEMs for the condition prior to the eruption of 2010. Satellite pour l’observation de la terre 6 (SPOT 6) stereo images acquired on 21 June 2015 and were used to make a DEM for that time. The results show that the estimated total volume of lava and pyroclastic deposits, produced during the period 2010 to mid-2015 is approximately 2.8 × 108 m3. This estimated volume of pyroclastic deposits can be used to predict the magnitude of future secondary lahar hazards, which are also related to the capacity of rivers in the area. Morphological changes are illustrated using cross-sectional analysis of the deposits, which are currently deposited to the east, southeast and south of the volcano. Such analyses can also help in forecasting the direction of the future flow hazards. The remote sensing and analysis methods used at Sinabung can also be applied at other volcanoes and to assess the threats of other types of hazards such as landslides and land subsidence. © 2016, Springer International Publishing.

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