Dalam pelaksanaan pengamatan hilal, Kementerian Agama RI dan NU telah mengakomodasi 105 lokasi di seluruh Indonesia, 53 lokasi diantaranya berada di Jawa Madura. Dari 53 lokasi tersebut, selama kurun waktu 10 tahun, laporan keberhasilan melihat hilal
ternyata hanya berasal dari 16 lokasi, sementara pengamatan di lokasi lainnya sering terkendala. Kenyataan ini mendorong munculnya pertanyaan: Bagaimana kelayakan lokasi pengamatan hilal di Jawa Madura? Mengapa keberhasilan lokasi pengamatan hilal tertentu lebih besar dari lokasi lainnya? Secara metodologis, penelitian ini menggunakan pendekatan kualitatif dengan alat ukur theodolit dan aplikasi google earth. Data pengamatan hilal diambil dari Rekapitulasi Data Penentuan Awal Bulan Ramadan, Syawal, dan Zulhijah Kementerian Agama RI Tahun 1430-1440 H/2009-2019 M. Sedangkan data kualitatif digali melalui wawancara dan observasi untuk melihat aspek yang mempengaruhi keberhasilan pengamatan hilal yang terkait dengan data geografi, topografi, dan kondisi meteorologis. Ada 27 lokasi pengamatan hilal yang diambil sebagai sampel, yang mewakili 3 kategori: observatorium, tempat tinggi, dan pantai. Teknik observasi dilakukan secara langsung dan tidak langsung melalui remote sensing, geographic information system, dan horizon distance. Selanjutnya, data-data tersebut dianalisis dengan metode induktif-deduktif, deskriptif interpretatif, dan penginderaan jauh.
Temuan dari penelitian disertasi ini adalah, Pertama, kondisi 27 lokasi pengamatan hilal di Jawa, Madura, secara geografis dan topografis, yaitu 10 lokasi pengamatan hilal terkategori layak ideal karena memenuhi bentangan medan pandang 57.3 derajat dan pandangan lepas ke arah ufuknya, 12 lokasi pengamatan hilal terkategori layak tidak ideal karena walaupun memenuhi bentangan medan pandang 57.3 derajat, akan tetapi ditemukan aspek pengganggu pandangan ke arah ufuknya, dan 5 lokasi pengamatan terkategori tidak layak karena memiliki bentangan medan pandang yang sempit, jarak pandang yang terhalang, dan ditemukan aspek pengganggunya berupa ketinggian tanah daratan, pepohonan, bangunan dan gunung. Namun secara meteorologis, keadaan cuaca lokasi-lokasi tersebut lebih sering berawan, dengan kondisi suhu antara 25-28°C dan kelembaban udara antara 85%-90%, bahkan hujan dengan keadaan suhu kurang dari 25°C dan kelembaban udara di atas 90%. Hal ini terkait dengan lokasi pengamatan hilal di Jawa, Madura yang terletak antara lintang 5°44'07" LS (Pantai Karya Kepulauan Seribu) dan 8°20'28" LS (Bukit Sadeng Jember), antara bujur 106°35'55" BT (Pantai Karya Kepulauan Seribu) dan 114°12'5.16" BT (Gumuk Klasi Banyuwangi). Lokasi -lokasi tersebut, karena berada dekat ekuator dan banyak mendapat sinar matahari, merupakan tempat proses fisis pembentukan awan, sehingga berpotensi berawan konvektif, di samping awan orografis yang dipicu gunung-gunung yang ada. Walaupun demikian, tetap ada laporan pengamatan yang dapat melihat hilal di beberapa lokasi. Kedua, pengamatan yang berhasil melihat hilal selama 10 tahun terakhir hanya di 16 lokasi, dengan dominasi 5 lokasi, yaitu di Bukit Condrodipo (16 kali), Pelabuhan Ratu (3 kali), Tanjung Kodok (3 kali), Pantai Gebang (2 kali), Jakarta Utara (2 kali), dan 11 lokasi lain (masing-masing 1 kali). Dominasi keberhasilan melihat hilal dipengaruhi oleh faktor-faktor yang mendukung dari aspek geografis, topografis, dan meteorologis: (a) faktor geografis-topografis berupa lokasi pengamatan hilal yang agak tinggi, dengan medan pandang ideal dari azimut 241.35-298.65 derajat, tidak terganggu oleh objek lain berupa permukaan tanah, pepohonan, atau bangunan, memiliki jarak pandang antara 10-25 km, serta memiliki nilai polusi cahaya sedang; (b) faktor meteorologis berupa kondisi cuaca cerah, dengan suhu udara antara 27.1°-29.5°C dan kelembaban 71-85%; dan (c) faktor non-alam yang turut mendukung keberhasilan melihat hilal adalah kekompakan dan kapabilitas tim perukyat serta dukungan kelengkapan peralatan yang dipergunakan dalam proses pengamatan.

ABSTRACT:
The Ministry of Religious Affairs of the Republic of Indonesia (MoRA) and Nahdlatul Ulama (NU) have accommodated 105 locations for hilal observation throughout Indonesia, 53 of which are in Java, Madura. Over 10 years, reports of success in seeing the new moon only came from 16 out of 53 locations, while observations at other locations report hampered. This fact leads to questions: first, what is the feasibility of the location for observing the new moon in Java-Madura? Why is the success of several observation locations greater than other locations? Second, why is the success of several hilal observation locations greater than other locations? This research applies a qualitative approach with theodolite and the google earth application as measuring instruments. The hilal observation data come from the Data Recapitulation on Determining the Beginning of the Months of Ramadan, Shawwal, and Zulhijah by the MoRA in 1430- 1440 H/2009-2019 AD. While, the qualitative data related to geographical, topographical, and meteorological aspects that affected the success of the hilal observation were collected through interviews and observations. There were 27 hilal observation locations taken as samples, representing 3 categories: observatories, high places, and beaches. Observation techniques are carried out directly and indirectly through remote sensing, geographic information system, and horizon distance. Furthermore, the data were analyzed using inductive deductive, descriptive-interpretative, and remote sensing methods.
The findings from this dissertation research are, First, geographically and topographically, the conditions of 27 hilal observing locations in Java, Madura, namely: 10 hilal observing locations are categorized as ideal because they cover a field of view of 57.3 degrees and views off towards the horizon, 12 hilal observing locations are categorized as not ideal because even though they meet the expanse of the terrain view of 57.3 degrees, but found aspects that interfered with the view towards the horizon, and 5 observation
locations were categorized as inappropriate because they did not meet the narrow field of view, obstructed visibility, and found disturbing aspects in the form of elevation of land, trees, buildings, and mountains. Meteorologically, the weather conditions are always cloudy, with temperature conditions between 25-28°C and air humidity between 85%-90%. It even often rains with conditions of temperature less than 25°C and air humidity above 90%. This circumstance is much related to the hilal observation locations in Java
Madura located between the latitude 5°44'07" (Pantai Karya Seribu Islands) and 8°20'28" (Bukit Sadeng Jember), between the longitude 106°35'55" (Pantai Karya Seribu Islands) and 114°12'5.16" (Gumuk Klasi Banyuwangi). Being near the equator and receiving intensive sunlight, these locations are places for the physical processes of cloud formation, so they have the potential for convective clouds in addition to orographic clouds triggered by existing mountains. However, there are still reports of observations that can see the new moon in several locations. Second, observations that have succeeded in seeing the new moon during the last 10 years have only been in 16 locations, with a dominance of 5 locations, namely at Bukit Condrodipo (16 times), Pelabuhan Ratu (3 times), Tanjung Kodok (3 times), Gebang Beach (2 times), North Jakarta (2 times), and 11 other locations (1 time each). The supporting factors in the success of seeing the new moon are geographical, topographical, and meteorological. (a) the geographical, and topographical factors are of relatively high locations for observing the new moon with an ideal field of view from an azimuth of 241.5- 298.5 degrees; not disturbed by other objects in the form of ground, trees, or buildings; have visibility between 10-25 km and have moderate light pollution values; (b) meteorological factors is of clear weather conditions, with the air temperature between 27.1°-29.5°C and humidity of 71-85%; and (c) non-natural factors that support the success of seeing the new moon are the cohesiveness and capability of the team as well as the adequate equipment used in the observation process.