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ACCURACY ASSESSMENTS OF PAN-SHARPENED IMAGE FOR BENTHIC HABITATS MAPPING Wicaksono, Pramaditya; Adhimah, Faza
Geoplanning: Journal of Geomatics and Planning Vol 4, No 1 (2017): April-Accepted papers (in proofreading process)
Publisher : Department of Urban and Regional Planning, Diponegoro University

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Abstract

Image-sharpening process integrates lower spatial resolution multispectral bands with higher spatial resolution panchromatic band to produce multispectral bands with finer spatial detail called pan-sharpened image. Although the pan-sharpened image can greatly assist the process of information extraction using visual interpretation, the benefit and setback of using pan-sharpened image on the accuracy of digital classification for mapping remain unclear. This research aimed at 1) highlighting the issue of using pan-sharpened image to perform benthic habitats mapping and 2) comparing the accuracy of benthic habitats mapping using original and pan-sharpened bands. Quickbird image was used in this study and Kemujan Island was selected as the study area. Two levels of hierarchical classification scheme of benthic habitats were constructed based on the composition of benthic habitats insitu. PC Spectral sharpening method was applied on Quickbird image. Image radiometric corrections, PCA transformation, and image classifications were performed on both original and pan-sharpened image. The results show that the accuracy of benthic habitats classification of pan-sharpened image (maximum overall accuracy 64.28% and 73.30% for per-pixel and OBIA respectively) is lower than the original image (73.46%, 73.10%). The main setback of using pan-sharpened image is the inability to correct the sunglint, hence adversely affects the process of water column correction, PCA transformation and image classification. This is mainly because sunglint do not only affect object’s spectral response but also the texture of the object. Nevertheless, the pan-sharpened image can still be used to map benthic habitats using visual interpretation and digital image processing. Pan-sharpened image will deliver better classification accuracy and visual appearance especially when the sunglint is low.
ASSESSMENT OF MANGROVE FOREST DEGRADATION THROUGH CANOPY FRACTIONAL COVER IN KARIMUNJAWA ISLAND, CENTRAL JAVA, INDONESIA Kamal, Muhammad; Hartono, Hartono; Wicaksono, Pramaditya; Adi, Novi Susetyo; Arjasakusuma, Sanjiwana
Geoplanning: Journal of Geomatics and Planning Vol 3, No 2 (2016): (October 2016)
Publisher : Department of Urban and Regional Planning, Diponegoro University

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Abstract

The Karimunjawa Islands mangrove forest has been subjected to various direct and indirect human disturbances in the recent years. If not properly managed, this disturbance will lead to the degradation of mangrove habitat health. Assessing forest canopy fractional cover (fc) using remote sensing data is one way of measuring mangrove forest degradation. This study aims to (1) estimate the forest canopy fc using a semi-empirical method, (2) assess the accuracy of the fc estimation and (3) create mangrove forest degradation from the canopy fc results. A sample set of in-situ fc was collected using the hemispherical camera for model development and accuracy assessment purposes. We developed semi-empirical relationship models between pixel values of ALOS AVNIR-2 image (10 m pixel size) and field fc, using Enhanced Vegetation Index (EVI) as a proxy of the image spectral response. The results show that the EVI provides reasonable estimation accuracy of mangrove canopy fc in Karimunjawa Island with the values ranged from 0.17 to 0.96 (n = 69). The low fc values correspond to vegetation opening and gaps caused by human activities or mangrove dieback. The high fc values correspond to the healthy and dense mangrove stands, especially the Rhizophora sp formation at the seafront. The results of this research justify the use of simple canopy fractional cover model for assessing the mangrove forest degradation status in the study area. Further research is needed to test the applicability of this approach at different sites.
Assessing the Capability of Sentinel-2A Data for Mapping Seagrass Percent Cover in Jerowaru, East Lombok Fauzan, Muhammad Afif; Kumara, Ignatius S. W.; Yogyantoro, Rifka N.; Suwardana, Satrio W.; Fadhilah, Nurul; Nurmalasari, Intansania; Apriyani, Santi; Wicaksono, Pramaditya
Indonesian Journal of Geography Vol 49, No 2 (2017): Indonesian Journal of Geography
Publisher : Faculty of Geography, Universitas Gadjah Mada

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Abstract

Remote sensing technology has been widely used in various applications related to natural resources and environment monitoring. In this paper, we evaluated the capability of new Sentinel-2A image to map the distribution and percent cover of seagrass in optically shallow water of Jerowaru coastal area, East Lombok. Seagrass distribution map was produced from radiometrically and geometrically corrected Sentinel-2A image with overall accuracy of 61.9%. Using empirical model, seagrass percent cover was predicted with maximum coefficient of determination (R2) of 0.51 and standard error of estimate (SE) of 19.4%. The results suggest that Sentinel-2A image can be used to perform seagrass mapping time and cost-effectively and can be further improved by incorporating more robust empirical modeling technique.
PENGARUH RESOLUSI SPASIAL CITRA TERHADAP HASIL PEMETAAN KANDUNGAN HARA NITROGEN PERKEBUNAN KARET Saputra, Jamin; Kamal, Muhammad; Wicaksono, Pramaditya
Jurnal Penelitian Karet JPK : Volume 36, Nomor 1, Tahun 2018
Publisher : Pusat Penelitian Karet - PT. Riset Perkebunan Nusantara

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Abstract

Nitrogen merupakan salah satu unsur hara yang dibutuhkan dalam jumlah banyak oleh tanaman. Tanaman yang mengalami kekurangan unsur hara nitrogen akan menyebabkan terhambatnya pertumbuhan dan penurunan produktivitas tanaman. Penerapan sistem pertanian presisi pada kegiatan pemupukan di perkebunan karet dilakukan dengan cara dosis pemupukan dibuat berdasarkan kandungan hara tanah dan kandungan hara pada tanaman. Pada areal yang luas membutuhkan biaya analisa hara tanaman yang cukup mahal. Oleh karena itu sangat dibutuhkan suatu teknologi yang dapat mengestimasi kondisi hara tanaman dengan cepat dan biaya yang murah. Teknologi penginderaan jauh merupakan alternatif yang dapat digunakan untuk areal yang luas dan dengan waktu yang cepat serta biaya yang relatif murah. Penelitian ini bertujuan untuk mengetahui pengaruh resolusi spasial citra terhadap peta hasil estimasi kandungan nitrogen perkebunan karet. Citra multi resolusi yang digunakan antara lain GeoEye-1 (2 m) Sentinel-2A (10 dan 20 m) dan Landsat 8 OLI (30 m). Metode yang digunakan adalah membangun hubungan semi-empiris antara band tunggal dan indeks vegetasi citra dengan kandungan hara nitrogen perkebunan karet. Hasil penelitian menunjukkan bahwa peta hasil estimasi kandungan hara nitrogen perkebunan karet menggunakan citra Sentinel-2A (SE 0,369) memiliki akurasi yang lebih tinggi dibandingkan dengan menggunakan citra GeoEye-1 (SE 0,519) dan Landsat 8 OLI (SE 0,462).
Akurasi geometri garis pantai hasil transformasi indeks air pada berbagai penutup lahan di Kabupaten Jepara Wicaksono, Arief; Wicaksono, Pramaditya
Majalah Geografi Indonesia Vol 33, No 1 (2019): Majalah Geografi Indonesia
Publisher : Fakultas Geografi, Universitas Gadjah Mada

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Abstract

Garis pantai merupakan salah satu data dasar dalam pemetaan yang harus dijamin ketersediaannya. Pesisir di Indonesia memiliki variasi penutup lahan sehingga karakteristik indeks air dalam memperoleh data garis pantai perlu diketahui agar pemanfaatan indeks air menjadi efektif. Tujuan penelitian ini adalah menghitung akurasi geometri garis pantai menggunakan transformasi NDWI, MNDWI, dan AWEI pada penutup lahan berbeda. Garis pantai hasil indeks air diperoleh dari citra Landsat 8 OLI, sedangkan garis pantai referensi untuk uji akurasi diperoleh dari interpretasi visual citra PlanetScope. Standar penilaian ketelitian horizontal garis pantai hasil indeks air menggunakan Perka BIG No 15 Tahun 2014. Hasil penelitian adalah pada nilai akurasi geometri garis pantai skala 1:100.000, tidak ada satu pun indeks air yang mampu mengakomodasi perolehan garis pantai pada semua kelas penutup lahan. Variasi nilai akurasi geometri setiap indeks air disebabkan oleh variasi kondisi citra, karakteristik saluran yang digunakan dalam formula indeks air, dan piksel campuran.
ANALISIS SALURAN SPEKTRAL YANG PALING BERPENGARUH DALAM IDENTIFIKASI KESEHATAN TERUMBU KARANG: Studi Kasus Pulau Menjangan Besar dan Menjangan Kecil, Kepulauan Karimunjawa Murti, Sigit Heru; Wicaksono, Pramaditya
MAJALAH ILMIAH GLOBE Vol 16, No 2 (2014)
Publisher : Badan Informasi Geospasial

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Abstract

ABSTRAKSalah satu faktor yang berpengaruh dalam penggunaan teknologi penginderaan jauh untuk identifikasi tingkat kesehatan terumbu karang adalah konfigurasi saluran spektral sensor. Pemahaman tentang saluran spektral yang berpengaruh positif terhadap proses identifikasi kesehatan terumbu karang sangat penting dalam efisiensi pemetaan, baik dari segi waktu maupun akurasi yang didapatkan. Penelitian ini bertujuan untuk mencari saluran spektral yang berkontribusi positif terhadap identifikasi kesehatan terumbu karang, dengan menggunakan bantuan analisis PCA (Principle Component Analysis) dan Factor Loadings pada citra Landsat 7 ETM+ dan ASTER. Tingkat kesehatan terumbu karang dilihat dari persentase tutupan karang hidupnya dan dibagi menjadi empat kelas yaitu Sangat Baik (>75% tutupan karang hidup), Baik (50-74%), Sedang (25-49%) dan Rusak (<25%). Untuk mengetahui saluran spektral yang paling baik dalam identifikasi kesehatan terumbu karang, klasifikasi multispektral dilakukan pada kombinasi PC (Principle Component) band dan dilakukan uji akurasi. Hasil uji akurasi dipasangkan dengan hasil analisis Factor Loadings untuk melihat kontribusi tiap saluran spektral pada tiap akurasi. Hasil penelitian menunjukkan bahwa saluran hijau merupakan saluran yang berkontribusi paling tinggi dan saluran merah adalah saluran memberikan kontribusi paling rendah. Saluran biru, yang merupakan saluran dengan penetrasi tubuh air paling baik, memberikan kontribusi yang lebih rendah dibandingkan dengan saluran hijau karena tingginya hamburan Rayleigh yang terjadi pada saluran biru tersebut.Kata Kunci: Landsat 7 ETM+, ASTER, PCA, factor loadings, terumbu karangABSTRACTOne of the major factors to determine the success of remote sensing identification for coral reefs health is the spectral resolution of the sensor. The understanding about the characteristic of spectral bands contribute positively to the identification of coral reefs health is very important for the effective and satisfactory mapping results. This research aimed to identify the most effective spectral band for the coral reefs health identification, using Principle Component Analysis (PCA) and factor loadings analysis. Landsat 7 ETM+ and ASTER VNIR images were used in this research. Coral reefs health condition is determined from the percentage of live coral cover and divided into four ordinal classes: very good (>75% live coral reefs cover), good (50-74%), medium (25-49%), and bad (<25%). To find the most effective bands for coral reefs health identification, multispectral classification was applied on Principle Component (PC) bands combinations. Afterward, the mapping accuracy of each PC bands combination was assessed. Each accuracy assessment result was evaluated with factor loadings analysis result to understand the contribution of different spectral bands on the resulting mapping accuracy. The results show that green band is the most effective spectral band which provides the highest contribution to the mapping, while red band provide the lowest contribution. Blue band, which is the best water penetration band, was less efficient than green band due to the strong Rayleigh scattering that affects more significantly on shorter wavelengths.Keywords: Landsat 7 ETM+, ASTER, PCA, factor loadings, coral reefs
Tidal Correction Effects Analysis on Shoreline Mapping in Jepara Regency Wicaksono, Arief; Wicaksono, Pramaditya; Khakhim, Nurul; Farda, Nur Mohammad; Marfai, Muh Aris
Journal of Applied Geospatial Information Vol 2 No 2 (2018): Journal of Applied Geospatial Information (JAGI)
Publisher : Politeknik Negeri Batam

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Abstract

The existence of high-spatial resolution imagery that are now available free by Planet Labs opens up opportunities in detailed scale mapping research, both as basic data and as reference data for geometry accuracy assessment. However, the use of several satellite sensors types with different recording times is the biggest obstacle in the use of high spatial resolution imagery as reference data because the shoreline instantaneous imaging at the data acquisition time does not consider the spatial and temporal variability of the shoreline boundaries. The purpose of this study was to analyze the effect of tidal correction on shoreline mapping in Jepara Regency using Landsat 8 OLI imagery in 2018.The effect of tidal correction analysis is done by comparing the position of the shoreline corrected by tides with the shoreline that is not corrected for tides. The influence of tidal correction is marked by differences in the position of the two shorelines. Shoreline shift calculation when there is a difference in tidal conditions between the test shoreline and the reference shoreline is carried out using the theory of right triangle (also called as one-line shift method).Based on the analysis of tidal correction effects, it is known that the shift in shoreline position after tidal correction varies from 0.21 m to 1.8 m, the value does not exceed one pixel of the PlanetScope image (3 m) so that tidal correction does not needs to be done because the effect is insignificant and undetectable on PlanetScope imagery. Keywords: tidal correction, shoreline, Planetscope, Landsat 8 OLI, Jepara
TOTAL SUSPENDED SOLID DISTRIBUTION ANALYSIS USING SPOT-6 DATA IN SEGARA ANAKAN, CILACAP Dhannahisvara, Aisya Jaya; Harjo, Hartono; Wicaksono, Pramaditya; Nugroho, Ferman Setia
Geoplanning: Journal of Geomatics and Planning Vol 5, No 2 (2018): (October 2018)
Publisher : Department of Urban and Regional Planning, Diponegoro University

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Abstract

Spatial distribution and concentration of Total Suspended Solid (TSS) is one of the coastal parameters which are required to be examined in order to understand the quality of the water. Rapid development of remote sensing technology has resulted in the emergence of various methods to estimate TSS concentration. SPOT-6 data has spatial, spectral, and temporal characteristics that can be used to estimate TSS concentration. The purposes of this research are (1) to determine the best method for estimating TSS concentration, (2) to map TSS distribution, and (3) to determine the correlation between TSS concentration and chlorophyll-a concentration using SPOT-6 data in Segara Anakan. The estimation of TSS concentration in this research was performed using empirical model built from SPOT-6 and TSS field data. Bands used in this research are single band data (blue, green, red, and near infrared) and transformed bands such as band ratio (12 combinations), Normalized Difference Suspended Solid Index (NDSSI), and Suspended Solid Concentration Index (SSC). The result shows that blue, green, red, and near infrared bands and SSC index significantly correlated to TSS. Afterwards, regression analysis was performed to determine the function that can be used to predict TSS concentration using SPOT-6 data. Regression function used are linear and non-linear (exponential, logarithmic, 2nd order polynomial, and power). The best model was chosen based on the accuracy assessment using Standard Error of Estimate (SE). The selected model was used to calculate total TSS concentration and was correlated with chlorophyll-a field data. The result of accuracy test shows that the model from blue band has an accuracy of 70.68 %, green band 70.68 %, red band 75.73 %, near infrared band 65.58 %, and SSC 73.67 %. The accuracy test shows that red band produced the best prediction model for mapping TSS concentration distribution. The total TSS concentration, which was calculated using red band empirical model, is estimated to be 6.13 t. According to the correlation test, TSS concentration in Segara Anakan has no significant correlation with chlorophyll-a concentration, with a coefficient correlation value of -0.265.
Aplikasi Citra WorldView-2 Untuk Pemetaan Batimetri Di Pulau Kemujan Taman Nasional Karimunjawa Rahman, Waskito; Wicaksono, Pramaditya
Jurnal Penginderaan Jauh Indonesia Vol 1 No 1 (2019): JPJI
Publisher : Masyarakat Ahli Penginderaan Jauh Indonesia (MAPIN) /Indonesian Society of Remote Sensing (ISRS)

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Abstract

The Application of WorldView-2 Image for Bathymetry Mapping in Kemujan Island Karimunjawa National Park The development of remote sensing technology gives an opportunity to extract bathymetry information on the optically shallow water area. This was done by utilizing the reflectance of spectral bands with the ability to penetrate water body. The aim of this research is to map bathymetry of Kemujan Island using remote sensing empirical modeling.  Quickbird image was used in this study. It has four spectral bands namely blue, green, red and near infrared band. These bands were rationed and acquired 12 band ratios. In total, 120 samples were used to produce bathymetry model and 379 samples were used for validation. The models were created for up to the depth of 7 m.  The result showed that the model from band ratio of green and blue band produced the highest accuracy with R² of 0.632 and SE of 1.2 m. The result proved that blue band is the most effective band to be combined with other bands for band ratio input for bathymetry modeling.
Improving Community Capacity in Rapid Disaster Mapping: An Evaluation of Summer School Sutrisno, Dewayany; Shih, Peter Tian-Yuan; bin Hashim, Mazlan; Qin, RongJun; Wicaksono, Pramaditya; Syaifoel, Rahman
Indonesian Journal of Geography Vol 51, No 2 (2019): Indonesian Journal of Geography
Publisher : Faculty of Geography, Universitas Gadjah Mada

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Abstract

Experiences with natural disasters have intensified recent efforts to enhance cooperation mechanisms among official disaster management institutions to community participation. These experiences reveal a need to enhance rapid mapping technical assistance to be developed and shared among young scientists through a summer school. However, the question arose of how effective this summer school to be used as a tool to increase scientists’ understanding and capacity. This study sought to evaluate the extent to which human resource capacity building can be effectively implemented. The methods used for this evaluation is through observations, questionnaires and a weighted scoring based on knowledge, skills and attitudes’ criteria. The results indicate a significant improvement in knowledge (94.56%), skills (82%) and attitudes (85.20%) among the participants. Even though there are still gaps in participants’ skills, the summer school was found to be an effective way to train the young scientists for rapid mapping.