Geomagnetic modification of the mid-latitude ionosphere: Toward a strategy for the improved forecasting of ƒ0F2

Posted On May 9 2021 by

first_imgThe reduction of maximum usable frequency (MUF) during a geomagnetic storm represents a serious hindrance to the efficient operation of HF transmission links. This paper outlines a new approach to the modeling and forecasting of ƒ0F2 at quiet and disturbed times. Statistical analyses of ionosonde data from the Argentine Islands (65°S) have been used to define patterns for the main phase effects of mid‐latitude ionospheric storms. Extended to a number of stations, these could be incorporated into algorithms to permit the forecasting of MUF for a few hours ahead and enhance the frequency management of shortwave radio communication. Data from a complete solar cycle, 1971–1981, are used to determine the errors in the forecasts and to demonstrate that a useful advantage can be attained by this method. The root‐mean‐square error in ƒ0F2 for 90,175 samples is 15.6%, which compares favorably with those obtained using forecasts based upon quiet time values (20.4%) or the previous day’s measurements (18%). Studies of error distribution with respect to local time, season, and phase of the solar cycle highlight limitations in the technique but also indicate avenues to further improvement.last_img read more


All Set for Peel Marina Dredging

Posted On Sep 28 2020 by

first_imgImage source: ManksviewWork to remove 44,000 tonnes of silt from Peel Marina is set to begin on Monday, 13 January.The first stage will see contractor Land and Water Services Limited (LAWS) construct a temporary draining pool in a field upstream from the marina, beyond the power station site.LAWS will be on site from next week and, following the construction of the pool, will start dredging in early March.The dredging process will involve using a long reach excavator on a floating barge, and the material will be transported 450 metres in purpose-designed trailers to the pool, which will be around 2.5 meters deep and measuring roughly 70m by 100m.Excess water will be drained back into the River Neb after satisfying environmental standards agreed with the Department of Environment, Food and Agriculture (DEFA).The material will be stored in the pool and drained over a number of months before being suitable for transportation.In previous plans, a proposal was made for the silt to be used for land remediation at the former Cross Vein Mine. This has now been revised, however, as the Department of Infrastructure is seeking to extend the range of materials that are deposited at the existing landfill facilities at Turkeylands Quarry, Malew.A planning application for the strategic waste facility is due to be submitted in early 2020 and will include details of the route to be used to transport material between Peel and Turkeylands.last_img read more


Anant Singh buys Mandela memorabilia

Posted On Dec 18 2019 by

first_imgA signed photograph of Nelson Mandela and Muhammed Ali, sold as part of a lot of rare Mandela memorabilia at a recent auction. By Anne Taylor2 December 2013A set of 79 photographs, memorabilia and documents signed by Nelson Mandela was bought at a recent auction for R950 000 by Anant Singh, the producer of the film Mandela: Long Walk to Freedom.The assortment of 79 signed mementos at the rare auction dated from 1964 to 2010 and included the historic “I am prepared to die” speech Mandela delivered from the dock in 1964 during the Rivonia Trial that sent him to prison.My favourite of all the things in the lot is the signed photograph of Mandela with boxer Muhammad Ali – the expression on Mandela’s face says it all, I reckon. Mandela’s signature is said to be the most valuable of any living figure.“I think it’s a fair price. I think the seller got a good price, the buyer got a great price,” Alan Demby, president of auction house Stephan Welz & Co, is reported by AFP as saying. “It’s more about what [Mandela] represents than the actual items.”“It’s not rare, it’s almost priceless. And I think that’s what makes it such a fascinating collection.” – Alan Demby, president of Stephan Welz & CoThe collection included a first-day cover from 10 May 1994, Mandela’s first day in office,  and a R5 inauguration coin. Also in the lot was a photograph of Mandela and Winnie entering a packed stadium in Soweto to address supporters after his release from jail in 1990, a 1988 concert pass for Mandela’s 70th birthday tribute at London’s Wembley Stadium, and a bottle of wine.last_img read more


Ricci Rivero leads Gilas team for Fiba 3×3 Asia Cup

Posted On Nov 27 2019 by

first_imgSBP condemns violent attack on referees during game in Olongapo Private companies step in to help SEA Games hosting ‘Rebel attack’ no cause for concern-PNP, AFP LATEST STORIES Two-day strike in Bicol fails to cripple transport Sports Related Videospowered by AdSparcRead Next DA eyes importing ‘galunggong’ anew The first order of business for the Rivero-led Philippine campaign is to top its group in the qualification phase to earn a berth in pool play.The Philippines is in Group A in the qualifier along with Qatar, Iran, Samoa and Thailand. The winner will be slotted with host China and New Zealand in the preliminary round.Rounding out the women’s squad, which is coached by Patrick Aquino, are electrifying guard Janine Pontejos, Afril Bernardino and Clare Castro.The Filipinas will also need to go through the qualifying stage against Chinese Taipei, Samoa and Vanuatu in Group A.ADVERTISEMENT Cayetano: Senate, Drilon to be blamed for SEA Games mess Duterte wants probe of SEA Games mess Ethel Booba twits Mocha over 2 toilets in one cubicle at SEA Games venue Catholic schools seek legislated pay hike, too MOST READ Trending Articles PLAY LIST 00:50Trending Articles00:50Trending Articles00:50Trending Articles02:42PH underwater hockey team aims to make waves in SEA Games01:44Philippines marks anniversary of massacre with calls for justice01:19Fire erupts in Barangay Tatalon in Quezon City01:07Trump talks impeachment while meeting NCAA athletes02:49World-class track facilities installed at NCC for SEA Games02:11Trump awards medals to Jon Voight, Alison Krauss MANILA, Philippines—Ricci Rivero and Jack Animam banner the Gilas Pilipinas’ men’s and women’s 3×3 teams, respectively in the Fiba 3×3 Asia Cup beginning Wednesday in Changsha, China.FEATURED STORIESSPORTSPrivate companies step in to help SEA Games hostingSPORTSPalace wants Cayetano’s PHISGOC Foundation probed over corruption chargesSPORTSSingapore latest to raise issue on SEA Games food, logisticsRivero, who has played in several international 3×3 competitions including the Fiba U23 World Cup last year, will be joined by Far Eastern University big man Barkley Ebona and high school standouts RJ Abarrientos and Rhayyan Amsali with Ronnie Magsanoc calling the shots.READ: PH taps its best for Fiba 3X3  Don’t miss out on the latest news and information. View commentslast_img read more