After years of preparation, the Indonesia National Observatory, located in Mount Timau, Kupang Regency, is currently in the completion stage of research in astronomy and astrophysics and related subjects. An optic telescope with a 3.8 m diameter is expected to receive its first light in mid-2024. A feasibility study for Indonesia’s radio telescopes and networks is in progress. A single-dish parabolic radio antenna with a diameter of 20 m is proposed to work in a frequency range of 1–50 GHz. An array dipole antenna with an area of 100 m × 100 m will also be installed at a 70–350 MHz frequency. A feasibility study about system design is in progress, and a radio frequency interference (RFI) survey has been underway since 2014. In this paper, we described the design of radio telescopes such as parabolic reflectors, horn antenna, and the radio frequency interference (RFI) in the surrounding area of the National Observatory, covering the frequency band from 45 MHz to 18 GHz. The frequencies in 45–85 MHz and 120–360 MHz intervals are still relatively quiet and suitable for developing radio telescopes. The selected higher frequency of 1.4 GHz for a neutral hydrogen (HI) spectral line, 6.6 GHz for a methanol (CH₃OH) spectral line, and 8.6 GHz for a helium (3 He+) spectral line is still relatively quiet and suitable for the development of radio telescopes.

Space Science Center of Indonesian Institute of Aeronautics and Space called LAPAN has installed several solar radio receivers named CALLISTO in various parts of Indonesia. The equipment has made some solar radio observational data which is indicate solar radio burst since its operation. All of the observational data stored in the file format of Flexible Image Transport System (FITS) which is the raw data. Therefore, it is required a such kind of related data processing to produce a data that can be used for further research. In this paper will discuss how the observational data of CALLISTO could be generated included the information of data format, CALLISTO data processing techniques used in these activities as well as some of the data processing based on data indicating solar radio bursts. As the results, a map of solar radio spectrum as spectrograph profiles and some determinations of frequency drift base on the data will also be discussed in this paper.

The formations type of solar radio bursts can be known base on the frequency range that is detected. The CALLISTO system works with a wide band of the frequency making it possible to detect several types of solar burst. Indonesia exactly at Sumedang, CALLISTO system detected the formation of solar radio bursts forms of type II for the first time on 5 November 2014. On the other side, CALLISTO spectrometer detects and traces the phenomenon of CME (Coronal Mass Ejections) which causes the solar radio burst type II occurrence. In this paper will be calculated frequency drift rate during the occurrence of solar radio bursts of type II phenomenon on 4th November 2015 at 03:30 UT. The results of these calculations will be discussed as a related study of drift rate during the phenomenon of burst type II radio bursts associated with CME. The obtained drift rate during the solar radio bursts events above 2.8 MHz / s with low drift rate so that the speed of the CME that occurred only about 790 km / s as shown from LASCO.

Near Vertical Incidence Skywave (NVIS) is one of the High Frequency (HF) radio communication modes that could be used for many activities on any circumstances due to its advantages. However, to ensure a communication’s success the working frequency or carrier frequency selection should be taken considerately based on the ionosphere condition that varies over time. This paper explains the development of the opening channel information system based on ionosphere observation over Kupang district, Nusa Tenggara Timur by pulsed HF radar or Ionosonde. The system periodically generates information from one-day observation of the Ionosonde’s echo intensity data (Ionogram) which were appended and converted to an image object. Further, the image processing technique is performed to reveal the information of the usable HF frequency range. The Connected Component Labelling and the Contour Detection methods were implemented to automatically determine the usable frequency of both the lowest and the most frequency values from echo data. The range of the frequency that could be reflected by the ionosphere is provided as the boundary of a lower and upper carrier frequency that could be chosen in NVIS communication as called usable HF frequency. This frequency-range information then could be used as a reference for selecting the carrier frequency with a radius up to 300 km from the center point of ionosphere observation.