Analisa sub-piksel citra terra modis untuk tanaman padi menggunakan metode linear spectral unmixing (Studi Kasus sebagian kabupaten Indramayu Jawa Barat)
Lisa Nisfi Afifah, Drs. Projo Danoedoro, M.Sc., Ph.D.
2009 | Skripsi | S1 KARTOGRAFI DAN PENGINDERAAN JAUHKajian terhadap objek padi memberikan nilai manfaat lebih besar sebagai informasi yang mengarah pada isu ketahanan pangan. Perbedaan waktu tanam padi pada suatu daerah akan mempengaruhi usia padi dan akhirnya berpengaruhi pada estimasi produksi panen, sehingga metode penentuan umur padi sangat bermanfaat sebagai dasar untuk estimasi produksi padi. Meskipun tiap fase padi berbeda secara fisik, namun perbedaan ini sulit dikenali dengan keterbatasan citra satelit. Tujuan penelitian ini adalah mendapatkan citra kelimpahan (abundance maps) 3 fase pertumbuhan padi dari metode Linear Sepctral Unmixing (LSU) dengan citra Terra MODIS. Sebagian desa di Kabupaten Indramayu dipilih sebagai lokasi penelitian karena adanya perbedaan usia tanam padi. Metode LSU menggunakan pendekatan analisa sub-piksel yang dapat memberikan informasi kehadiran endmember (piksel murni) dalam satu piksel citra. Nilai spektral endmember didapat dari pustaka spektral (spectral library) padi fase vegetatif, generatif, dan ripening hasil pengukuran di lapangan. LSU menghasilkan abundance maps dan RMSE map. Abundance maps menunjukkan persentase keberadaan endmember, dan RMSE map menunjukkan persentase kesalahan klasifikasi. Jumlah dan ragam endmember sangat mempengaruhi hasil LSU. Pada kasus ini metode LSU dianggap mampu memisahkan 3 fase pertumbuhan padi dengan nilai RMSE yang diperoleh adalah 0.02%.
Study of paddy gives significant benefit in the context of food resistant issue. Time variation of paddy planting affect the variation of harvest time, which means that there is variation of rice production time by time. Thus, the method of determining paddy's age is very useful as a basic for estimating rice production. Although each paddy phase is physically different, it is difficult to recognize using satellite imagery because of limitation spatial resolution. The aim of this research was to get the abundance maps represenly of 3 phases of paddy using Linear Sepctral Unmixing (LSU) method base on Terra MODIS image. Several villages in Indramayu District were selected as a study area due to its complete coverage of rice with different age relevant to this study. LSU method with sub pixel analysis approach could give information of the endmembers (pure pixel) presence in one image pixel. Endmember spectral values were taken from spectral library of vegetative and generative phases of paddy, and also of ripening from field measurement using spectrometer. LSU generates abundance and RMSE map. The obtained abundance maps showed the percentage of endmember existing on the image and the RMSE map showed the percentage of classification errors. The number and differentiation of endmember gives a significant impact to LSU result. In this case, LSU method was considered to be able to separate 3 phase of paddy growth with RMSE value 0.02%.
Kata Kunci : Linear Spectral Unmixing, MODIS, Padi,Linear Spectral Unmixing, MODIS, Paddy
