Modification of ITU-R Rain Fade Slope Prediction Model Based on Satellite Data Measured at High Elevation Angle

Abstract

Rain fade slope is one of fade dynamics behaviour used by system engineers to design fade mitigation techniques (FMT) for space-earth microwave links. Recent measurements found that fade slope prediction model proposed by ITU-R is unable to predict fade slope distribution accurately in tropical regions. Rain fade measurement was conducted in Kuala Lumpur (3.3° N, 101.7° E) where located in heavy rain zone by receiving signal at 10.982 GHz (Ku-band) from MEASAT3 (91.5° E) on 77.4° elevation angle. The measurement has been carried out for one year period. Fade slope S parameter on ITU-R prediction model has been investigated. New parameter is proposed for the fade slope prediction modeling based on measured data at high elevation angle, Ku-band. ABSTRAK: Cerun hujan pudar adalah salah satu dinamik tingkah laku pudar yang digunakan oleh jurutera sistem untuk mereka bentuk teknik-teknik pengurangan pudar (FMT) bagi link gelombang mikro ruang bumi. Ukuran baru-baru ini mendapati bahawa cerun pudar ramalan model yang dicadangkan oleh ITU-R tidak mampu untuk meramalkan pengagihan cerun pudar tepat di kawasan tropika. Pengukuran hujan pudar telah dijalankan di Kuala Lumpur (3.3° N, 101.7° E) yang terletak di kawasan hujan lebat dengan menerima isyarat pada 10,982 GHz (Ku-band) dari MEASAT3 (91.5° E) pada sudut ketinggian 77.4°. Pengukuran telah dijalankan untuk tempoh satu tahun. Parameter cerun pudar S pada model ramalan ITU-R telah disiasat. Parameter baru adalah dicadangkan untuk pemodelan cerun pudar ramalan berdasarkan data yang diukur pada sudut paras ketinggian, Ku-band.KEYWORDS: fade slope; ITU-R; fade mitigation techniques; sampling time interval

Analysis of rain fade duration over satellite-earth path at Ku-Band in tropics

“…0.2 mm tipping-bucket rain gauge is integrated in the system and logged every 10s time interval to measure rainfall rate and determine rainy events. System elaboration can be found in [4].…”

“…Average fade duration is a ratio of annual accumulated time duration T tot to annual number of occurrence event N tot at a given fade threshold as presented in (3) (4) Fade duration is analysed based on two data sets such as filtered and unfiltered data. Unfiltered data is noticeably shown that it has higher number of events and exceedance times than filtered data.…”

Scintillation measurement on Ku-band satellite path in tropical climate

“…Raining events were manually removed based on 0.2 mm tipping bucket rain gauge which is time synchronized measurement. Details of the experimental setup are available in [4,5].…”

Statistical Analysis of Rain at Millimeter Waves in Tropical Area

“…Video streaming was performed over a high-speed link via the WINDS satellite in a tropical area (Singapore) to investigate the effects of rainfall on the signal strength of the link and the video quality [11]. The rain induced scintillation was studied based on attenuation measurement over a one year period during 2011 and 2012, from MEASAT3 satellite at Ku-band (12)(13)(14)(15)(16)(17)(18) in Malaysia [12]. In [13], the performance of the Silva Model in [14] for rain attenuation prediction in slant paths for satellite links was investigated and compared to the ITU-R P.618-11 model [15] based on data from three slant paths in tropical regions of Malaysia [16], [17] and Australia [18].…”