IR Susceptibility of Supersonic Aircraft according to Omni-directional Detection Angle

Infrared guided weapons act as threats that greatly degrade the survivability of combat aircraft. Infrared weapons detect and track the target aircraft by sensing the infrared signature radiated from the aircraft fuselage. Therefore, in this study, we analyzed the infrared signature and susceptibility of supersonic aircraft according to omni-directional detection angle. Through the numerical analysis, we derived the surface temperature distribution of fuselage and omni-directional infrared signature. Then, we calculated the detection range according to detection angle in consideration of IR sensor’s parameters. Using in-house code, the lethal range was calculated by considering the relative velocity between aircraft and IR missile. As a result, the elevational susceptibility is larger than the azimuthal susceptibility, and it means that the aircraft can be attacked in wider area at the elevational situation.

Distributions of environmental parameters and fish at Humbold Bay, Jayapura

Research on the distribution of fish and plankton in waters that are equipped with environmental parameters is needed to obtain maximum results and increase accuracy also it provides comprehensive information. The research, which was conducted in Humbold Bay, aimed to map the fish and plankton distribution data both vertically and horizontally and combine it with environmental parameters in the bay. Fish and plankton’s data was the volume backscattering strength (Sv) value obtained using the SIMRAD EK-15 device while environmental parameter data, such as temperature, salinity, and chlorophyll obtained from marine.copernicus.eu which processed in the 5-80 m depth range. The results showed that Humbold Bay had the highest average surface temperature distribution was 30 °C, with the highest average salinity from 35.89 ppt and the highest average chlorophyll value from 0.3859 mg/m3. The horizontal distribution of plankton had an average SV value of -76.63 dB, while the fish was -56.00 dB that evenly distributed. Vertically, the Sv of plankton decreased with increasing depth as well as the Sv of fish which its’ also did not have a distribution pattern in certain environmental parameters.

Mapping of Sea Surface Temperature Distribution, Sibolga City, North Sumatera Province using NOAA/AVHRR Satellite

The research was aimed to map the sea surface temperature (SST) distribution in Sibolga waters that based on 20 years satellite image of NOAA/AVHRR. It used survey method for ground check in the field to collect in situ SST and other seawater parameters such as its visibillity, pH, and salinity. It found that the SST changes on each 5 year’s calculations with different pattern of distribution; the figures of SST ranged between 28.5-30 oC, 30.5-31 oC, 27-29 oC, and 27.5-28.5 oC. In addition, the pH of seawater ranged from 6-7 and 27-30 ppt in average. Different pattern of SST distribution might be related to global change on temperature and season over 20 years of study.