Coherent marine radar measurements of properties of ocean waves and currents

Author(s):  
Dennis Trizna
1985 ◽  
Vol 38 (1) ◽  
pp. 23-38 ◽  
Author(s):  
Ian Robert Young ◽  
Wolfgang Rosenthal ◽  
Friedwart Ziemer

1984 ◽  
Vol 35 (6) ◽  
pp. 239-241 ◽  
Author(s):  
T D Allan

2018 ◽  
Vol 17 (1) ◽  
pp. 26
Author(s):  
Pitjont Tomatala ◽  
Petrus Paulus Letsoin ◽  
Evangelin Martha Yulia Kadmaer

<p align="center"><strong>Abstract</strong></p><p>Sea cucumber <em>Holothuria </em>sp. is a marine biota that has economic value. The rearing activity of sea cucumbers is still limited to the have bay or strait areas with relatively calm coastal. This research aimed to determine the effectiveness of two types of pen‒culture system for sea cucumber rearing to the influence of ocean waves and currents. This research was done from February to July 2017 in the coastal of Rat village, Southeast Maluku Regency. The two of cultivated containers tested were a conventional pen‒culture (treatment A) and engineered pen‒culture (treatment B). A total of 30 individuals sea cucumber seeds sized 4‒6 cm were released at each pen‒culture. Survival rate and water quality were also calculated as supporting data. Observation of endurance and clearance of pen‒culture was done every two weeks. The result of visual observation showed that conventional pen‒culture treatment A was more quickly damaged and it was more damaged compared to engineered pen-culture treatment B.Through t‒test we got T <sub>count</sub> (1.065) &lt; T<sub>table</sub> (6.313) for survival and T <sub>count</sub> (0.084) &lt; T<sub>table</sub> (1.782) for growth. The result means that treatment A and treatment B have the same effect onsurvival rate and growth of sea cucumber. The results showed that treatment B was better applied to more open waters than treatment A.</p><p> </p><p>Keyword: endurance, pen‒culture, sea cucumber, survival, growth</p><p> </p><p> </p><p align="center"><strong>Abstrak</strong></p><p>Teripang <em>Holothuria </em>sp. merupakan biota laut yang memiliki nilai ekonomis. Kegiatan budidaya teripang masih terbatas pada daerah‒daerah yang berteluk atau berselat dengan perairan yang relatif tenang. Penelitian ini bertujuan untuk membandingkan efektivitas dua sistem budidaya teripang dalam kurungan tancap terhadap pengaruh gelombang laut dan arus. Penelitian ini berlangsung dari bulan Februari hingga Juni 2017 di perairan Desa Rat, Kabupaten Maluku Tenggara. Dua tipe wadah budidaya yang diujicobakan adalah kurungan tancap konvensional (perlakuan A) dan kurungan tancap yang direkayasa (perlakuan B). Pada setiap kurungan tancap, dimasukkan teripang pasir berukuran 4‒6 cm sebanyak 30 ekor. Sebagai data pendukung, dihitung persentase kelangsungan hidup dan pengukuran kualitas air. Pengamatan ketahanan dan kebersihan kurungan tancap dilakukan setiap dua minggu sekali. Hasil pengamatan visual diketahui bahwa kurungan tancap perlakuan A lebih cepat rusak dan mengalami kerusakan yang lebih besar dibandingkan perlakuan B. Melalui uji-tdiperoleh hasil T<sub>hitung</sub> (1,065) &lt; T<sub>tabel</sub> (6,313) untuk kelangsungan hidup, dan T<sub>hitung </sub>(0,084) &lt; T <sub>tabel</sub> (1,782) untuk pertumbuhan.  Hasil uji‒t bermakna bahwa perlakuan A dan perlakuan B memiliki pengaruh yang sama terhadap kelangsungan hidup dan pertumbuhan teripang. Hasil pengamatan menunjukkan bahwa perlakuan B lebih baik diaplikasikan pada perairan yang lebih terbuka dibandingkan perlakuan A.</p><p> </p><p>Kata kunci: ketahanan, kurungan tancap, teripang, kelangsungan hidup, pertumbuhan</p><p> </p>


Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5639
Author(s):  
David Lyzenga ◽  
Mirko Previsic

Marine radars have proven to be useful for measuring ocean waves, but the accuracy of the measurements is limited by several factors including the look-angle dependence of the radar signals as well as noise in the radar data. The look-angle dependence introduces a systematic error or bias in the measurements, and noise causes a random error. This paper describes a method of combining data from multiple radar frames that is optimal in the sense of minimizing the error for a set of biased measurements with random additive noise. The results are shown experimentally to increase the correlation of the radar estimates with buoy measurements.


2017 ◽  
Author(s):  
Giovanni Ludeno ◽  
Francesco Raffa ◽  
Francesco Soldovieri ◽  
Francesco Serafino

Abstract. This letter presents the monitoring results of the sea waves and the surface currents obtained by analyzing data acquired by a X-band marine radar in two different operative conditions, namely the short and medium pulse modes. In particular, we investigated the feasibility to use a medium radar pulse for sea state monitoring by comparing the performance in both the radar modes. The comparison was carried out by means of an experimental campaign and we observed a good agreement for surface current and sea state parameters estimation.


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