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All Journal Jurnal Online Mahasiswa (JOM) Bidang Perikanan dan Ilmu Kelautan Jurnal Penginderaan Jauh dan Pengolahan Data Citra Digital Indonesian Journal of Aerospace
Rahmat Arief, Rahmat
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Aerospace Engineering Agriculture, Biological Sciences & Forestry Astronomy Computer Science & IT Control & Systems Engineering Earth & Planetary Sciences Electrical & Electronics Engineering

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Identification of Water Quality Status In the Upstream of the Siak River, Kampar, using a Storet Method Arief, Rahmat; Sumiarsih, Eni; El Fajri, Nur
Jurnal Online Mahasiswa (JOM) Bidang Perikanan dan Ilmu Kelautan Vol 5 (2018): Edisi 1 Januari s/d Juni 2018
Publisher : Jurnal Online Mahasiswa (JOM) Bidang Perikanan dan Ilmu Kelautan

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ABSTRAKIn the upstream of the Siak River, there are various activities, such as palm plantations, palm oil industry, fishcapture andwater transportation that  produce pollutant and thus affect the water quality. A research aims to determine the quality and quality status of the upstream waters of the Siak River, a study was conducted from April-May 2017. The  water was sampled at 3 stations, with 3 replications. Water quality parameters measured were temperature, pH, current speed, dissolved oxygen, depth, and brightness (in the field), BOD5, COD, TSS, Nitrate, Phosphate, Oil and Fat (in laboratory). Results shown thatthe BOD5 is 16.7 - 38.9 mg/L and oil and fat content was 86,000-339,000 mg/L, these values are higher that that of the standard issued by the Indonesian government. The water temperature ranges from 30-31oC, pH5, current speed 0.3-0.4cm/s, dissolved oxygen 3.1-4.4 mg/L, depth 4-5 m, brightness 35-61cm, COD 8.5-17.6 mg/ L, nitrate 0.56-1.29 mg/L and phosphate 0.24-0.28 mg/L.based on data obtained, it can be concluded that upstream of the Siak River is classified as moderately polluted (score ranged from -20 to - 22). Key words: polluted river,palm oil industry, oil dan fat
MODIFIKASI DIGITAL ELEVATION MODEL (DEM) CITRA RESOLUSI TINGGI MENGGUNAKAN FUSI INTERFEROMETRI SAR DAN STEREOSAR BERBASIS FAKTOR PEMBOBOTAN Dyatmika, Haris S.; Arief, Rahmat; Sudiana, Dodi; Ali, Shadiq; Maulana, Rachmat; Budiono, Marendra Eko
Jurnal Penginderaan Jauh dan Pengolahan Data Citra Digital Vol. 15 No. 2 (2018)
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30536/inderaja.v15i2.3343

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SAR satellite sensors are capable to measure elevation of the earth surface using interferometry (InSAR) or radargrammetry (StereoSAR) methods. The InSAR method utilizes phase value from SAR images, while the StereoSAR uses amplitude value to produce elevation of the earth surface. Both methods have advantages and disadvantages on each own. Problems with low accuracy on DEM generated using InSAR occur on shadow and layover area, while in the second method (StereoSAR) the problem arise when cross correlation between the two images have low value. This paper proposes a technique to combine InSAR and StereoSAR methods to generate DEM using high resolution SAR images. A pair of TerraSAR-X or TanDEM-X images with a 21 degree incidence angle are used in this study and processed using the InSAR method and another pair of images at an angle of 21 degrees and 41 degrees using the StereoSAR method in Bandung and surrounding areas. The experimental results show that the fusion DEM of the two methods have better accuracy and decrease the absolute error both from InSAR and StereoSAR technique methods that separately around 3.48 m and 1.80 m.
Time Optimization for Lossy Decompression of the LISA Sensor Data on LAPAN A3 Satellite Using a Grouping Method of HUFFMAN Code Bit Number Suhermanto, Suhermanto; Arief, Rahmat
Indonesian Journal of Aerospace Vol. 16 No. 1 Juni (2018): Jurnal Teknologi Dirgantara
Publisher : BRIN Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30536/j.jtd.2018.v16.a2960

Abstract

The LAPAN-A3 satellite provides compressed multispectral data from LISA sensor using real-time lossy compression. The compression of the multispectral data of radiometric resolution 12bit/pixel is built from the Fourier transform and the use of Huffman decoder 514 binary length code. A problem arised in the data extraction process, that decompression performance is very slow because the search method of code value in Hufman table was done sequentially from one bit to the next bit in one block of data along 4000 pixels. The data extraction time for one scene in 12 minutes acquisition duration (one full path) takes up to 20 hours. This paper proposes a method of improving the LISA real-time lossy data decompression algorithm using the grouping method of bit code on the Huffman decoding algorithm and using pointer for reading data in the buffer memory. Using this method, the searching process of bit code for all characters in the Huffman decoder algorithm is done regularly, so the search processing time is significantly reduced. The performance test used 6 data samples. The result showed that extraction time has an average of 14 times faster. The lossy compression ratio is still in accordance with the design specification of LISA sensor that is less than 4 times and the appearance of the special character is very small i.e. less than 0.5%.
Co-Authors Ali, Shadiq Dodi Sudiana Dyatmika, Haris S. Eni Sumiarsih Marendra Eko Budiono, Marendra Eko Nuraini El Fajri Rachmat Maulana Suhermanto, Suhermanto