Network of Automatic Weather Stations : Pseudo random burst sequence type

A network of 125 Automatic Weather Stations (AWS) has been set up by India Meteorological Department (IMD) during the year 2006-07 across India. Each station is configured to measure air temperature, hourly maximum temperature, hourly minimum temperature, relative humidity, station level pressure, hourly rainfall and cumulative rainfall for the day, Wind speed and Wind direction. In addition to these parameters, 25 stations provide data for global solar radiation and soil temperature. Five stations also provide soil moisture in addition to soil temperature. Each station transmits a data stream at an interval of an hour in a Pseudo Random Burst Sequence (PRBS) manner via UHF transmitter and a dedicated meteorological satellite KALPANA-1/ INSAT-3A to the central AWS data receiving Earth Station facility established at IMD, Pune. Mean sea level pressure, dew point temperature, duration of bright sunshine and daily maximum & minimum temperature are derived at the receiving Earth Station. Data archival in near real time is done at the receiving Earth Station. Data dissemination in WMO code form is also done in near real time through Global Telecommunication System. This paper provides technical description of various sub-systems of PRBS type Indian Automatic Weather Station network including instrument, satellite transmission technique, sensor characteristics, siting and exposure conditions and performance of a representative station.

Technical feasibility on reception of VHRR signals from Kalpana-1 satellite in the event of contingency with the existing operational ground receiving system

National Satellite Meteorological Center (NSMC), of India Meteorological Department is performing the vital role of receiving signals of meteorological data transmitted by KALPANA-1/INSAT series of national satellites and processing the data to generate various meteorological products for monitoring meteorological, environmental and climatological conditions. The satellite signals are currently being received through a 7.5 m diameter parabolic dish antenna installed at INSAT Earth Station of IMD located at Mausam Bhawan Complex, New Delhi. In this study an attempt has been made to receive and process the VHRR signals of KALPANA-1 through a smaller (3.8m) diameter parabolic dish antenna available at earth station .The link calculations have been made to show extra 2 db margin what is theoretically required and it will be sufficient for image capturing. We had also compared the result with existing 7.5m diameter antenna and observe that quality of satellite pictures received with 3.8m diameter antenna are also equally good. The purpose of this study is to keep in operational readiness a backup antenna for the reception of KALPANA-1 in the event of any unforseen contingency with the existing 7.5m diameter parabolic dish antenna, using the existing infrastructure of IMD.

Analysis the impact of sun outage and satellite orbit at performance of the telkom 3S satellite communication system

Satellites of communication are located at altitude of thousands kilometers above the earth's surface, so the signal is transmitted by satellite to earth station is very susceptible to interference. Every March and September equinox or when the sun crosses the Earth's equator for several days, earth station occurs a naturally interference called by sun outage. At this time, satellite and the sun reach the closest distance because satellite's position is same direction with the sun. This interference makes the signal received by earth station weaken and even disappears due to temperature noise which increases drastically. Loss of signal on the downlink side caused by noise greatly affects to the performance of satellite communication system. This study aims to analyze the effect of sun outage and satellite orbit to determine sun outage period on the performance of Telkom 3S satellite communication system. The results obtained that indicate the signal quality is represented by degradation in the Carrier to Noise Ratio (C/N) from 14,777 dB to 6,0 dB, Energy bits per Noise Ratio (Eb/No) from 11,515 dB to 2,738 dB, and increase the Bit Error Rate (BER) from 8,29×10-7 to 11,08×10-3. In addition, sun outage makes lost of satellite communication traffic and affecting link availability to 99,855324%. Meanwhile, the result from satellite orbit calculation for sun outage period based on ITU-R S.1525 standard and based by satellite’s handbook. Keywords – Telkom 3S satellite, sun outage, C/N, Eb/No, BER, link availability, sun outage period.

Distance Protection for Coexistence of 5G Base Station and Satellite Earth Station

In this paper, we investigate the coexistence of the 5G communication network with a fixed-satellite service (FSS) in the 3.5 GHz and 26 GHz frequency bands. We analyze a distance protection scheme for the FSS Earth station (ES) and 5G base stations (BS). Furthermore, we define the exclusion and restriction zones to develop a transmit power control scheme based on the Citizens Broadband Radio Service (CBRS). An interactive power control scheme is also devised for the restriction zone and extensively analyzed through simulations. The proposed scheme is examined for practical scenarios such as the rural macrocells (RMa), urban macrocells (UMa), and urban microcells (UMi) as defined by the 3GPP. The impact of the antenna type is also investigated, and BSs with omnidirectional, 4 × 4, 8 × 8, and 16 × 16 antenna arrays are examined, as defined by 3GPP, for the 5G networks. The results confirm that 5G systems can coexist with the FSS and provide quantitative insights into the selection of the system parameters, including interference margins, exclusion sizes, and reduction zones, for different scenarios and antenna types.

ANALISA KINERJA PELAYANAN KERETA LIGHT RAIL TRANSIT RUTE A-B PALEMBANG DENGAN METODE RAILQUAL DAN QUALITY FUNCTION DEMAND LAMPUNG, LAMPUNG

A rapid development has resulted in the level of urbanization in several big cities getting more advanced. transportation needs will be very important for the community, especially Palembang City, South Sumatra region. Transportation is a means to facilitate the movement of an object from one place to another. PT KAI is a monopoly company without equal participants, so this research is important to conduct research for that. target vision with case studies on LRT (Light Rail Transit) passengers.The research was conducted by means of a survey to see the performance of the LRT Train (Light Rail Transit). The object of the survey is the people who are on the LRT (Light Rail Transit) train at DJKA-Bumi Sriwijaya station. The data obtained were then processed with the SPSS software program.1.Djka Station - Sriwijaya Earth Station The significant variable R Square indicates that the value of R Square is 0.965. This value illustrates that the variables X1, X2, X3, X4, X5, X6, X10 on passenger satisfaction are 96.5% in the model proposed in this study.2.Djka Station - Sriwijaya Earth Station The significant variable R Square shows that the value of R Square is 0.969. This value illustrates that the contribution of the variables X1, X2, X3, X4, X7, X8 to passenger satisfaction is 96.9% in the model proposed in this study.3.Djka Station - Sriwijaya Earth Station Significant variable R Square obtains an R Square value of 0.973. This value illustrates that the contribution variable X1, X2, X3, X4 to passenger satisfaction is 97.3% in the model proposed in this study.