Agus D. Prasetyo

Automated ground station with customized rotator for antenna pointing using compass sensor

The antenna pointing system is very important to obtain an optimum received signal level. To achieve it, the pointing mechanism has to be set in automatic mode. In this research, the automatic antenna pointing system is developed by using compass sensor CMPS10 as a feedback. Beside CMPS10, the angle estimation has been calculated by TLE orbital satellite to predict the movement of tracked satellite. This system has been tested to track NOAA19 with differences between the prediction angle with the real satellite angle about 5 degree on the average. On the rotator system, by using 2 gears and 2 DC motors with customized frames, the system has been realized and tested. There are 3 tests to be done: the test of power supply circuit, the elevation and azimuth power requirement tests, and the mechanical tests. The design of the customized rotator system resulting the azimuth speed is 7.3 degree per second on the average, while the elevation speed has 7.7 degree per second on the average. The rotator also has been tested with some loaded-unloaded schemes to clarify the ability of rotator system. The load-tests show that on the average 98 kilograms-load for azimuth movement needs 58.8 Watts supply; and 54 kilograms-load for the elevation movement needs 198 Watts.

A preliminary design and testing of the On Board Data Handling (OBDH) for nano-satellite using an atmospheric balloon

There are must-to-do steps in the nano-satellite development process, including the engineering model and flight model test. The atmospheric balloon test can be used to analyze the On Board Data Handling (OBDH) performance. The obtained results from the test are 13 images data captured from the 2900 MASL maximum altitude, also the sensor data i.e. temperature, pressure, humidity, position, and the direction of the balloon payload.

Planar inverted-F antenna (PIFA) array with circular polarization for nano satellite application

In this paper, a new design of an S-band, self phased, planar inverted-F antenna (PIFA) is proposed for low orbit nano satellite application. The antenna consists of Four PIFAs which are arranged in circular array to generate circular polarization antenna. The antenna operates at 2.35 GHz with 107 MHz bandwidth of Return Loss less than -14 dB. Results show that the antenna has circular polarization properties with 1.21 dB axial ratio and unidirectional radiation pattern. Since the proposed antenna is compact and low cost, it is suitable for nano satellite communication system.

Analysis of camera array on board data handling using FPGA for nano-satellite application

Nanosatellite has limited functions because of the mass constraint from 1 to 10 kg. Therefore, the requirement of low cost, low mass, low dimension, and low power consumption must be fulfilled in designing and choosing the component of nanosatellite. To obtain wider coverage area while maintaining the low dimension, camera array was used to produce image with wider area. In this research, On Board Data Handling (OBDH) implemented in FPGA used below 100% of the total FPGA resource. LUT-FF pairs was the most used resource with 75% of usage. OBDH also combined the image from each camera to get image with wider area. The FPGA and 4 cameras used 2264.44 milliwatt of power consumption, higher than the remote sensing system of SNAP-1 nanosatellite which used 1 milliwatt of power consumption.

Design of attitude determination and control system using microstrip magnetorquer for nanosatellite

Magnetorquer is a type of active control used on nanosatellite. It can be made by using microstrip line with a circular spiral patch. In previous research, the magnetorquer system was designed by using a coil of wire wrapped around the cross-section of conductor. The magnetic field is generated by electrifying the coil of wire. The torque is produced when the magnetic field generated from magnetorquer interacts with the Earths magnetic field. The torque can be controlled to change nanosatellite orientation in its orbit. In this paper, the magnetorquer is designed with 5 V of voltage consumption and 0.5-1 A of current consumption. By supplying the magnetorquer with various amount of current, the minimum and maximum values of magnetic field are 0.811 μT and 1.596 μT respectively.

Dual-feed orthogonal circular polarized microstrip antenna with front-end parasitic for Inter Satellite Link

A novel circularly polarized microstrip antenna using dual-feed orthogonal and with front-end parasitic method is proposed in this paper. In the feeding network, a two-way circular-sector power divider is adopted to distribute the current equally to each feed. A method of moments is employed for optimizing the design and achieving a good circular polarization at the center frequency of 2.37 GHz. The simulated values shows that 3-dB axial ratio bandwidth and maximum gain are about 51MHz and 6.39dBic. The narrow bandwidth and reasonable gain indicate that antenna is promising for Inter Satellite Link in S-Band.