International Journal of Remote Sensing and Earth Science Vol. 17 No. 2 December 2020: 189-200 A COMPARISON OF RAINFALL ESTIMATION USING HIMAWARI-8 SATELLITE DATA IN DIFFERENT INDONESIAN TOPOGRAPHIES

Nadine Ayasha1* 1Indonesian Agency of Meteorology Climatology and Geophysics *e-mail: [email protected] Received: 08 October 2020; Revised: 27 November 2020; Approved: 21 December 2020

Abstract. The Himawari-8 satellite can be used to derive precipitation data for rainfall estimation. This study aims to test several methods for such estimation employing the Himawari-8 satellite. The methods are compared in three regions with different topographies, namely Bukittinggi, and Ambon. The rainfall estimation methods that are tested are auto estimator, IMSRA, non-linear relation and non- linear inversion approaches. Based on the determination of the statistical verification (RMSE, standard deviation and correlation coefficient) of the amount of rainfall, the best method in Bukittinggi and Pontianak was shown to be IMSRA, while for the Ambon region was the non-linear relations. The best methods from each research area were mapped using the Google Maps Application Programming Interface (API).

Keywords: Rainfall Estimation, Himawari-8 Satellite, Google Maps API

1 INTRODUCTION systems has contributed greatly to their Remote sensing is the science of use in weather forecasts (Tan, 2014). In obtaining information about the Earth's fact, observations using weather satellites surface without having direct contact can provide hourly weather information with it. This is done by sensing and over a fairly wide area coverage. Such recording the reflected energy and environmental and weather satellite data processing, analysing and applying the can be obtained real time, but their use information (NRC, 2003). Nowadays, remains very limited in the wider remote sensing for the observation of the community (Suwarsono et al., 2009). atmosphere is very important. This is However, the most recent weather because not all areas on the earth's satellite and its data can be used by the surface can be covered by in situ wider community, namely the Japanese observations (Alfuadi, 2016). In addition, Himawari-8 satellite, which is a new remote sensing has contributed greatly to generation of meteorological satellites various other fields and led to the with sophisticated optical sensors development of various sensors (Lillesand (Bessho et al., 2016). In addition, et al., 2015). Remote sensing sensors precipitation data can be derived from the themselves are divided into two types, Himawari-8 satellite data which can be namely remote sensing with active useful in mitigating hydrometeorological instruments sensors as found in weather disasters (Alfuadi, 2016). radar and passive instrument sensors Several studies using the Himawari- found in weather satellites (Stull, 2015). 8 satellite have also been conducted to Weather satellites can be used to estimate rainfall in various areas. For identify cloud patterns and structures example, Rani, et al. (2016) used the auto related to dynamic weather conditions. estimator method in Pangkalpinang The development of weather satellite Meteorological Station; the INSAT 189 http://dx.doi.org/10.30536/j.ijreses.2020.v17.a3441 @National Institute of Aeronautics and Space of (LAPAN) Nadine Ayasha Multispectral Rainfall Algorithm (IMSRA) method was employed by Alfuadi (2016) in Palangkaraya; and the non-linear relation method with non-linear inversion were used by Alfuadi and Wandala (2016) in Muara Teweh and Palangkaraya. However, some of these studies only focus on one region topography. In fact, the latitude, slope and altitude in some areas will affect weather activities, such as cloud formation and rain, due to the Figure 2-1: Map of the research area uneven solar irradiation on the earth's The data used were from Himawari- surface (Sucahyono and Ribudiyanto, 8 channel IR-1, obtained from 2009). Therefore, it is necessary to ftp://202.90.199.115. IR-1 was used conduct research into and test the because IR-1 data can be converted into methods used for different topography precipitation data (Alfuadi, 2016). The and weather systems. This study verification of the rainfall estimation was proposes to test the methods that are made using rainfall data from the AWS generally used in various topographies in center BMKG. Rainfall date cases were Indonesia (highlands, lowlands and employed in the research are shown in islands). Apart from testing the methods, Table 2-1: the research will display rainfall estimation results into Google Maps Table 2-1: Rainfall date cases (Source - BMKG, 2017 and 2018) Application Programming Interface (API) Bukittinggi platform. 15 April 2017 Heavy rainfall (60.8 The Google Maps API platform mm/day) allows users to integrate Google Maps into 25 June 2017 Moderate rainfall their respective websites by adding their (36.9 mm/day) own data points (Davis, 2006). The 28 June 2017 Moderate rainfall (46.5 mm/day) advantage of the API is that it is possible Pontianak to modify maps according to user needs 10 Sept 2017 Heavy rainfall (70.8 and integrate them with the data to be mm/day) used (Akanbi and Agunbiade, 2013). 11 Nov 2017 Very Heavy rainfall Therefore, this study will utilise the (187.4 mm/day) 13 Oct 2018 Heavy rainfall (76.4 Google Maps API to add data points in the mm/day) form of rainfall estimation results (light, Ambon moderate, heavy and very heavy rain) into 28 May 2018 Very heavy rainfall a map which interesting and easy to (100.2 mm/day) understand by users 29 June 2018 Very heavy rainfall (111 mm/day) 30 June 2018 Heavy rainfall (75 2 MATERIALS AND METHODOLOGY mm/day) 2.1 Location and Data The locations of this research were The tools used in the research were in Bukittinggi (GAW Bukit Kototabang), Python 3.7 to extract the value of the Pontianak (Supadio Meteorological cloud top temperature (T) from the IR-1 Station) and Ambon (Pattimura data. These data are in netCDF (.nc) Meteorological Station) (as shown in red format, so Python 3.7 extracted the on the map in Figure 2-1). temperature in this format. JavaScript

190 International Journal of Remote Sensing and Earth Science Vol. 17 No. 2 December 2020 A Comparison of Rainfall… was also used to prepare the sripct or the and T is the cloud top temperature in mapping of rainfall estimation, and the Kelvin. Google Maps API platform was used for mapping the best method of rainfall 2.2.2 Statistical Verification Method estimation result. After obtaining the results of the rainfall estimation described above, we 2.2 Methods verified the results using RMSE, Two methods were employed, correlation coefficient and standard rainfall estimation equation and deviation and incorporated them into a statistical verification of the rainfall Taylor diagram. We also calculated the estimation method bias of the rainfall estimation.

2.2.1 Rainfall Estimation Method a. RMSE a. Auto Estimator Based on Wang and Lu (2018), the Based on Vicente et al (1998), the RMSE equation is : equation for auto estimator is : 2 ∑푁 (푥i−푦푖) (2-5) RMSE = √ 푛=1 R = 1.1183 .1011 푒푥푝(−3.6382 .10−2 .푇1.2) (2-1) 푁 where R is the rainfall estimation where N is the amount of data, xi is the (mm/hour) and T is the cloud top rainfall estimation (mm) and yi is the real temperature in Kelvin. observation of rainfall (mm).

b. Correlation Coefficient b. IMSRA In line with Saefuddin et al (2009), The equation used in the research of the correlation coefficient equation is : Gairola et al. (2011) was :

훴(푥푖−푥̅)(푦푖−푦̅) (2-6) R=8.613098 ∗ 푒푥푝 (−(T−197.97)/15.7061 ) (2-2) rxy = √∑(푥푖−푥̅ )2√∑(푦푖−푦̅ )2 where R is the rainfall estimation where xi is the rainfall estimation (mm) (mm/hour) and T is the cloud top and yi is the real observation of rainfall (mm). temperature in Kelvin.

c. Bias c. Non-Linear Relation Bias is used to establish whether The equation used in the research of the value of the data is underestimated or Suwarsono et al. (2019) was : overestimated. The equation of bias based

R = 2 .1025 .T −10.256 (2-3) on Santos et al (2011) is :

1 Bias = ∑푛 (푥푖 − 푦푖) (2-7) Where R is rainfall estimation (mm/hour) 푁 푖=1 and T is the cloud top temperature in Kelvin. where xi is the rainfall estimation (mm)

and yi is the real observation of rainfall d. Non-Linear Inversion (mm). Based on Octari et al (2015), the equation for non-linear inversion is : d. Standard Deviation Based on Supranto (2008), the R = 1.380462 .10−7 푒3789.518 /T (2-4) equation of standard deviation is:

Where R is rainfall estimation (mm/hour) International Journal of Remote Sensing and Earth Science Vol. 17 No. 2 December 2020 191 Nadine Ayasha

2 ∑푁 (푥i−µ) (2-8) was the case on 25 and 28 June 2017. σ = √ 푛=1 푁 Furthermore, based on the rainfall bias graph (Figure 3-2), on 15 April 2017 there 2 where (xi-µ) is the deviation from was an increased in rainfall bias the observation to the true mean. (overestimation) in the auto estimator and

non-linear relation methods. This is 3 RESULTS AND DISCUSSION because of a time lag between the 3.1 Rainfall Estimation Results detected cloud top temperature and the Beside the statistical verification real rainfall. On 25 June 2017, there was results, the determination of the best a drastic reduction (underestimation) at method was also based on the Taylor 12.00 UTC. This was due to 22.9 mm/hr diagram results (the red point closest to of heavy rainfall resulting from cloud top the observation point being the best temperature -6.4350C. In other words, method). rain comes from cloud with warm cloud

top temperature. a. GAW Bukit Kototabang On the other hand, on 28 June Bukittinggi 2017, the non-linear relation method Based on the statistical verification tended to overestimate and there was a results (Table 3-1) and the Taylor diagram reduction at 13.00UTC, which was due to (Figure 3-1), out of three dates, two (25 a time lag (on 12.00 UTC, the cloud top and 28 June 2017) indicate that IMSRA is temperature was -52.50C, but the rain not the best method. It has the best rainfall falling directly to the earth. The heavy estimation when rain intensity is less rain fell to the earth on 13.00 UTC when than 5-6 mm/hour (Alfuadi, 2016), which the cloud top temperature had increased).

A B

C

Figure 3-1: A. Taylor diagram on 15 April 2017; B. Taylor diagram on 25 June 2017; C. Taylor diagram on 28 June 2017

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Table 3-1: Rainfall Estimation Results for GAW Bukit Kototabang, Bukittinggi RMSE STDEV Dates Methods Correlation (mm/day) (mm/day) Auto Estimator 6.36 0.72 9.03 15 April IMSRA 4.54 0.69 1.32 2017 Non-Linear Relation 6.88 0.68 9.35 Non-Linear Inversion 3.83 0.70 3.18 Auto Estimator 4.98 -0.19 0.40 25 June IMSRA 4.95 -0.24 0.25 2017 Non-Linear Relation 6.08 -0.23 2.64 Non-Linear Inversion 5.01 -0.23 0.43 Auto Estimator 4.24 0.11 2.97 28 June IMSRA 3.37 0.15 0.79 2017 Non-Linear Relation 6.99 0.16 6.71 Non-Linear Inversion 3.53 0.14 1.58

A B

C

Figure 3-2: Rainfall Bias Graph for GAW Bukit Kototabang Bukittinggi (A. 15 April 2017; B. 25 June 2017; C. 28 June 2017)

b. Supadio Meteorological Station less than 5-6 mm / hour (Alfuadi, 2016). Pontianak This was the same case as Bukittinggi, The statistical verification results where the dominant hourly rainfall was (Table 3-2) and the Taylor diagrams also less than 5-6 mm / hour, so (Figure 3-3) shows that IMSRA was the Bukittinggi and Pontianak have the same best method for the Supadio best rainfall estimation method. Meteorological Station. On 10 September Moreover, one of the reasons why 2017, 11 November 2017 and 13 October Bukittinggi and Pontianak have the same 2018, the method produced the best best rainfall estimation method is results because the dominant hourly because both regions arein the equatorial rainfall (from AWS) had an intensity of rainfall category.

International Journal of Remote Sensing and Earth Science Vol. 17 No. 2 December 2020 193 Nadine Ayasha Generally, rainfall bias on 10 phase does not immediately produce September 2017 showed that there was heavy rainfall that falls to the Earth's time lag between the detected cloud top surface. In addition, the influence of rapid temperature and the actual rainfall in cloud and wind movement affected the Pontianak, which as shown in Figure 3-4 accuracy of rainfall in Pontianak and thus A. This was because the low temperature influencing the rainfall bias. of the cloud tops, which in the mature

A B C

Figure 3-3: A. Taylor Diagram on 10 September 2017; B. Taylor Diagram on 11 November 2017; C. Taylor Diagram on 13 October 2018

Table 3-2 : Rainfall Estimation Results for Supadio Meteorological Station Pontianak RMSE STDEV Dates Methods Correlation (mm/day) (mm/day) Auto Estimator 25.61 -0.12 23.31 10 Sept IMSRA 8.68 -0.13 2.09 2017 Non-Linear Relation 16.87 -0.12 13.82 Non-Linear Inversion 10.84 -0.12 6.17 Auto Estimator 34.06 -0.02 24.25 11 Nov IMSRA 23.36 0.04 1.92 2017 Non-Linear Relation 25.70 0.07 12.56 Non-Linear Inversion 24.09 0.006 6.04 Auto Estimator 9.97 0.05 2.83 13 Okt IMSRA 9.64 0.14 0.62 2017 Non-Linear Relation 10.12 0.16 4.94 Non-Linear Inversion 9.65 0.11 1.30

194 International Journal of Remote Sensing and Earth Science Vol. 17 No. 2 December 2020 A Comparison of Rainfall…

A B

C

Figure 3-4: Rainfall Bias Graph for Supadio Meteorological Station Pontianak (A. 10 September 2017; B. 11 November 2017; C. 13 October 2018)

Furthermore, on 11 November cloud top temperature only played a 2017, there was a decrease in the bias minor role in the rainfall process on this value (Figure 3-4 B) at 08.00 UTC due to date. The rainfall process is not only actual rainfall (from AWS) reaching 108.6 influenced by the cloud top temperatures, mm/hour, but the cloud top temperature but can also be influenced by the was only -37.5710C. In addition, there is conditions and composition of the an increase in the bias value at 10.00 atmosphere, circulation and local UTC due to the low temperature of the top atmospheric dynamics (Avia & Haryanto, cloud of -75.2890C, although the actual 2013) as well as by local convection rainfall (from AWS) is 0 mm/hour. This currents (Marpaung, 2010) in Pontianak. was contrary to the principles that the lower the cloud top temperature, the c. Pattimura Meteorological Station higher it’s potential to produce a rainfall. Ambon Rain events on this date indicate that low The statistical verification results cloud top temperatures do not always (Table 3-3) and Taylor diagrams (Figure 3- produce heavy rains, and vice versa 5) show that the non-linear relation (Nurasniyati et al., 2018) method was the best for Pattimura The rainfall bias graph of 13 October Meteorological Station Ambon. 2018 (Figure 3-4 C) shows that there was The best dominant rainfall a significant decrease in the bias value at estimation method for the Ambon region 06.00 UTC. This was because the cloud is therefore different to that of the top temperature at 06.00 UTC was only - Pontianak and Bukittinggi areas. This 35.470 C, but produces heavy rainfall up could be a result of the topographical to 49.6 mm/hour (from AWS). This conditions of Ambon, which affect the further reinforces the notion that the process of rainfall formation. In addition,

International Journal of Remote Sensing and Earth Science Vol. 17 No. 2 December 2020 195 Nadine Ayasha Ambon has a local type of rainfall pattern dramatically (underestimated). This was characterised by the extent of the because the rainfall fell to the earth's influence of local conditions, such as the surface came from cloud tops with the presence of mountains, oceans, other temperatures of -36.279, -42.25 and - water landscapes, and the occurrence of 35.670 C. The hours of 13.00, 14.00 and intensive local warming (Tukidi, 2010). 16.00 UTC are the time when peak The condition of Ambon, which has a local rainfall occurs, with an intensity of 23, type of rainfall pattern and is heavily 17.4 and 16.4 mm/hour (from AWS). This influenced by local characteristics shows that the cloud top temperature (Tjasyono and Harijono, 2013) will affect only makes a small contribution to the the distribution of rain. The distribution process of very heavy rain. This process of rain will affect the characteristics of can be influenced by local factors such as rainfall in an area, .meaning the wind, and water vapour estimation results will be affected (Nurasniyati et al., 2018). There is a gap There was very intense rainfall in the rainfall bias data at 22.00 UTC, reaching 100.2 mm / day on 28 May because the Himawari-8 satellite could 2018. Rainfall bias graph at Figure 3-6 A not detect the cloud top temperature, so shows that at 13.00, 14.00 and 16.00 it could be converted into rainfall by the UTC, the rainfall bias had decreased quite four methods.

A B C

Figure 3-5: A. Taylor Diagram on 28 May 2018; B Taylor Diagram on 29 June 2018; C. Taylor Diagram on 30 June 2018

Table 3.3 Rainfall Estimation Result at Pattimura Metetorological Station Ambon RMSE STDEV Dates Methods Correlation (mm/day) (mm/day) Auto Estimator 5.81 0.39 1.23 28 May IMSRA 5.93 0.55 0.50 2018 Non-Linear Relation 5.13 0.58 4.67 Non-Linear Inversion 5.77 0.52 0.91 Auto Estimator 8.33 0.31 4.90 29 June IMSRA 7.99 0.50 0.98 2018 Non-Linear Relation 7.73 0.54 7.70 Non-Linear Inversion 8.33 0.31 4.90 Auto Estimator 6.52 0.30 0.04 30 June IMSRA 6.50 0.43 0.07 2018 Non-Linear Relation 6.13 0.47 1.00 Non-Linear Inversion 6.48 0.43 0.12

196 International Journal of Remote Sensing and Earth Science Vol. 17 No. 2 December 2020 A Comparison of Rainfall…

A B

C

Figure 3-6: Rainfall Bias Graph in Pattimura Meteorological Station Ambon (A. 28 May 2018; B. 29 June 2018; C. 30 June 2018)

Furthermore, based on Figure 3-6 The rainfall bias graph on Figure 3- B, the time lag influenced the rainfall 6 C shows that there was a decrease in bias. There was an increase in this bias the rainfall bias (underestimation). This (overestimation) at 01.00 UTC, especially was caused by heavy rainfall (22 and 23.4 for the auto estimator and non-linear mm/hour) at 01.00 and 04.00 UTC, relation method. The different results in although the detected cloud top the bias were caused by the estimated temperatures were only -8.64404 and - rainfall results due to the low cloud top 12.219970 C. The cloud observations at temperature (-61.539980C), whereas the Pattimura Meteorological Station showed actual rainfall (based on AWS data) was Cumulus (Cu) clouds at 01.00 and 04.00 only 2 mm/hour. In other words, this UTC. In other words, heavy rain is shows that a low cloud top temperature generated from Cu clouds, not does not always produce heavy rain at Cumulunimbos (Cb) ones with low cloud that time. Likewise, at 04.00 UTC, there top temperatures. was a decrease in the rainfall bias (underestimation), because the rain fell 3.2 Visual Comparison Map of the heavily when the cloud top temperature Rainfall Estimation gradually rose to -51.708010 C from - In the rainfall estimation map, the 61.539980C. There are a data gaps in the blue colour shows light intensity rain, rainfall bias data at 00.00, 06.00 and green shows moderate rain intensity, 23.00 UTC, because the Himawari-8 purple colour shows heavy intensity rain satellite could not detect the temperature and red very heavy/ extreme rain. of the cloud tops, so it cannot be Mapping using Google Maps API only converted into rainfall by the four takes one date and a certain hour of rain methods. events as an example.

International Journal of Remote Sensing and Earth Science Vol. 17 No. 2 December 2020 197 Nadine Ayasha a. GAW Bukit Kototabang Bukittingi estimation results from the IMSRA method were mapped using Google Maps API for 10 September 2017. Based on the the rainfall estimation results in Figure 3- 8, it can be seen that the IMSRA method produced an estimate of moderate rainfall at the Supadio Meteorological Station at 10.00 UTC.

c. Pattimura Meteorological Station Ambon Figure 3-7: Mapping of Rainfall Estimation Results on 28 June 2017 at 12.00 UTC using Google Maps API

As the IMSRA method is the best method in Bukittinggi based on the results and discussion in section 3.1, the rainfall estimation result from the IMSRA method were mapped using Google Maps API for 28 June 2017. Based on the rainfall estimation results in Figure 3-7, it Figure 3-9 : Mapping of Rainfall Estimation can be seen that the IMSRA method Results on 29 June 2018 at produced an estimate of light rainfall in 05.30 UTC using Google Maps API GAW Bukit Kototabang at 12.00 UTC. In addition, the rainfall estimation from the As the non-linear relation method is IMSRA method produced the lowest the best method for Ambon based on amount of rainfall in comparison to the results and discussion on section 3.1, the other three methods, but this was closer rainfall estimation results from non- to the actual rainfall levels. linear relation method were mapped

using Google Maps API for 29 June 2018. b. Supadio Meteorological Station Based on Figure 3-9, it can be seen that Pontianak the non-linear relation method produced

as heavy rainfall estimation for Pattimura Ambon Station. Rainfall estimation using this method produced a high level of rainfall compared to the other three methods. This was influenced by the ability of the algorithm in the four methods to estimate rainfall.

4 CONCLUSION Based on the results and discussion Figure 3-8 : Mapping of Rainfall Estimation above, we can conclude that : Results on 10 September 2017 at 10.00 UTC using Google Maps a. The best method for estimating API rainfall in Bukittinggi is the IMSRA

method, with an RMSE of 3.37 to As the IMSRA method is the best 4.95 mm/day, a correlation method in Pontianak based on the results coefficient of -0.24 to 0.15 and a and discussion in section 3, the rainfall

198 International Journal of Remote Sensing and Earth Science Vol. 17 No. 2 December 2020 A Comparison of Rainfall… standard deviation of 0.25 to 0.79 REFERENCES mm/day. Akanbi A.K., & Agunbiade, O.Y. (2013), b. The best method for estimating Integration of a city GIS data with Google rainfall in Pontianak is the IMSRA Map API and Google Earth API for a web- method, with an RMSE of 8.68 to based 3D Geospatial Application. 23.36 mm/day, a correlation International Journal of Science and coefficient of -0.13 to 0.14 and a Research (IJSR) 2(11), 200-203. standard deviation of 0.62 to 2.09 Alfuadi N. (2016). Interkomparasi Teknik mm/day. Estimasi Curah Hujan. Prosiding Seminar c. The best method for estimating Nasional Sains Atmosfer, 151-162. rainfall in Ambon is the non-linear Alfuadi, N., & Wandala, A. (2016). Comparative relation method, with an RMSE of Test of Several Rainfall Estimation 5.13 to 7.73 mm/day, a correlation Methods Using Himawari-8 Data. coefficient of 0.47 to 0.58 and a International Journal of Remote Sensing standard deviation of 1.0 to 7.7 and Earth Science 3(2), 95-104. mm/day. Avia, L.Q., & Haryanto, A. (2013). Penentuan d. The conclusion from the visual Suhu Threshold Awan Hujan di Wilayah comparison map of the rainfall Indonesia Berdasarkan data satelit estimation shows that it can clearly MTSAT dan TRMM. Jurnal Sains describe the types of cloud and the Dirgantara 10(2), 82-89. results of the estimated rainfall. Bessho, K., Date K., Hayashi M., Ikeda A., Imai e. The physiographical conditions of T., Inoue H., …Yoshida, R. (2016). An Indonesian territory, such as its Introduction to Himawari-8/9-Japan’s latitude, altitude, wind patterns New-Generation Geostationary (trade and monsoon winds), Meteorological Satellites. Journal of the distribution of land and waters, and Meteorological Society of Japan 94(2), 151- mountains have an effect on 183. variations and types of rainfall in the Gairola, R.M., Varma A.K., Prakash, S., Mahesh, country (equatorial, monsoon and C., Pal, P.K. (2011). Development of local types), including rainfall Rainfall Estimation Algorithms for estimation. Monitoring Rainfall Events over India f. In further research, it will be Using KALPANA-IR Measurements on necessary to process satellite data Various Temporal and Spatial Scales. 38th and considerable rainfall data (1-5 Meeting of the Coordination Group of years), because this study Meteorological Satellites (CGMS), New investigates whether different Delhi, India, 8–12 November. topographies affect the results of Lillesand, T.M., Kiefer R.W., & Chipman J.W. rainfall estimation in each region. (2015). Remote Sensing and Image Interpretation (7th ed), USA: John Wiley & ACKNOWLEDGEMENTS Sons, Inc. This paper was written Marpaung, S. (2010). Pengaruh Topografi independently and I would like to thank Terhadap Curah Hujan Musiman dan Mrs. Fitria Puspitasari, SST, M.Sc for Tahunan di Provinsi Bali Berdasarkan providing advice on the methods for data Observasi Resolusi Tinggi. Prosiding estimatinge rainfall. I would also like to Seminar Penerbangan dan Antariksa, 104- thank my senior Muhammad Ryan for 110. providing advice regarding the programming for the paper.

International Journal of Remote Sensing and Earth Science Vol. 17 No. 2 December 2020 199 Nadine Ayasha

NRC (2003). Fundamentals of Remote Sensing, A Supranto, J. (2008). Statistik Teori dan Aplikasi. Canada Centre for Remote Sensing : Penerbit Erlangga. Remote Sensing Tutorial, Canada. Stull, R. (2015). Practical Meteorology-An Nurasniyati, Muliadi, & Adriat R. (2018). Algebra-based Survey of Atmospheric Estimasi Curah Hujan di Kota Pontianak Science. University of British Columbia, Berdasarkan Suhu, Ketebalan dan Canada. Tekanan Puncak Awan. Jurnal Prisma Sucahyono, D., & Ribudiyanto, K. (2009). Cuaca Fisika 6(3), 184-189. dan Iklim Ekstrim di Indonesia. Octari, G.R., Suhaedi D., & Noersomadi, (2015). Puslitbang, Badan Meteorologi Model Estimasi Curah Hujan Klimatologi dan Geofisika. Berdasarkan Suhu Puncak Awan Suwarsono, P., Kusumaning A.D.S., & Menggunakan Inversi Nonlinear. Kartasamita M. (2009). Penentuan Prosiding Penelitian SPeSIA 2015 Bid. Hubungan Antara Suhu Kecerahan Matematika 1(1), 23-29. dangan MTSAT dengan Curah Hujan Data Rani, N.A., Khoir, A.N., & Afra S.Y. (2016). QMORPH. Jurnal Penginderaan Jauh 6(1), Rainfall Estimation Using Auto-Estimator 32-42. Based On Cloud-Top Temperature Of Tan, S.Y., (2014), Meteorological Satellite Himawari 8 Satellite Compared To Rainfall Systems. France : Springer. Observation In Pangkalpinang Tjasyono, B.H.K., & Harijono S.W.B. (2013). Meteorological Station. Proceedings The Atmosfer Ekuatorial, Puslitbang, Badan 6th International Symposium for Meteorologi Klimatologi dan Geofisika. Sustainable Humanosphere, 1(1), 93-98. Tukidi (2010). Karakter Curah Hujan di Saefuddin, A., Notodiputro K.A., Alamudi A., & Indonesia, Jurnal Geografi 7(2), 136-145. Sadik, K. (2009). Statistika Dasar. Wang, W., & Lu Y. (2018). Analysis of the Mean Jakarta: PT Grasindo. Absolute Error (MAE) and the Root Mean Santos, C.A.C.D., Silva B.B.D., Rao T.V.R.R., Square Error (RMSE) in Assessing Satyamurti P., & Manzi A.O. (2011). Rounding Model. IOP Conference Series: Downward Longwave Radiation Estimates Materials Science and Engineering, 324(1), For Clear Sky Conditions Over Northeast 1-10. Brazil. Revista Brasileira de Meteorologia 26(3), 443-450.

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