SISTEM PERHITUNGAN LAMA PENYINARAN MATAHARI DENGAN METODE OTSU THRESHOLD (STUDI KASUS: ST. KLIMATOLOGI BARONGAN)

Asih Pujiastuti, Agus Harjoko

Submitted : 2017-10-23, Published : .

Abstract

Solar radiation measurements in climatology station barongan done by using campbell stokes and record card. Solar radiation is the accumulation of the whole length of the object radiation recorded on the record card. Solar radiation data reading performed by observers by estimating the long of object irradiation compared with the scale of hours listed on the record card. The difficulties encountered by observers in conducting solar radiation data readout is the shape of the object radiation recorded on the record card are not always in the form of elongated areas, some areas disjointed, even can only form small holes along the track on the card record. The purpose of this study was to design and build a system that can be used to calculate solar radiation recorded on the card record, thus increasing the accuracy of measurement data readout. Cropping process is carried out in order to obtain the right area for analysis. The approach method in object segmentation is done by implementing a solar radiation threshold otsu method. The test results showed that the determination o f the radius o f the opening and removing noise value appropriately irradiation can obtain the number o f objects on test images with RMSEof1.4429 compared with the amount o f exposure o f the image o f the original object. Results o f calculation solar radiation by the system showed system RMSE o f 0,51 to observer calculation.

Keywords

otsu threshold, cropping, opening, removing noise

References

Ariffin, dkk., 2010, Modul Praktikum Klimatologi. Fakultas Pertanian Universitas Brawijaya, Malang.

BMKG, 2006, Peraturan Kepala Badan Meteorologi dan Geofisika no SK/32./TL.202/KB/BMG-2006.

Fan, Q., dan Zhang, Y., 2013, A scorch extraction method for the Campbell-Stokes sunshine recorder based on multivariable thresholding. Imaging Systems and Techniques (IST), IEEE

International Conference on, 410 - 414.

Gonzalez, R.C. dan Woods, R.E., 200S, Digital Image processing, Addison- Wesley Publishing Company, USA.

Hamdi, S., 2014, Mengenal Lama Penyinaran Matahari Sebagai Salah Satu Parameter Klimatologi. Berita Dirgantara, 75(1), 7-16.

Horseman, a. M., Richardson, T., Boardman, a. T., Tych, W., Timmis, R., dan MacKenzie, a. R., 2013, Calibrated digital images of Campbell-Stokes recorder card archives for direct solar

irradiance studies. Atmospheric Measurement Techniques, 6(5), 1371-1379.

Lakitan, B., 1994, Dasar-dasar Klimatologi. Jakarta: PT. Rajagrafindo Persada.

Muhsoni.F.,F. Effendy M,danTriajie, H.2009. Pemetaan Lokasi Fishing Ground dan Status Pemanfaatan Perikanan di Perairan Selat Madura.Ilmu Kelautan Universitas Trunojoyo Madura

Otsu, N., 1979, A Threshold Selection from Gray-level Histograms, Systems Man Cybernet. IEEE, vol. 6, hal. 62-69.

Sanchez-Romero, a., González, J. a., Calbó, J., dan Sanchez-Lorenzo, a., 2014, Using digital image processing to characterize the Campbell-Stokes sunshine recorder and to derive high-temporal, resolution direct solar irradiance. Atmospheric Measurement Techniques Discussions, 7(9), 9537-9571.

Sutoyo, T., Mulyanto, E., Suhartono, V., Nurhayati, O. D., dan Wijanarto., 2009. Teori Pengolahan Citra Digital. Yogyakarta, Indonesia: Andi Offset dan UDINUS Semarang.

Swarinoto Y. S. , 2011, Pemanfaatan Suhu Udara dan Kelembapan Udara Dalam Persamaan Regresi Untuk Simulasi Prediksi Total Hujan Bulanan di Bandar Lampung. Jur. Met. Geo., 12 (3), 269-279.

Tjasyono, B., 2004, Klimatologi (2nd ed.). Bandung: ITB.

Wilks, D.S., 1995, Statistical Methods in theAtmospheric Sciences. San Diego: Academic Press Inc.

WMO, 2008. Guide to Meteorological Instruments and Methods of Observation, WMO-No.8 seventh edition.

Wood, C. R., dan Harrison, R. G., 2011, Scorch marks from the sky. Weather, 66, 39-41.

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