1080i is an abbreviation referring to a combination of frame resolution and scan type, used in high-definition television and high-definition video. The number "1080" refers to the number of horizontal lines on the screen; the "i" is an abbreviation for "interlaced". A related display resolution is 1080p, which has 1080 lines of resolution; the term assumes a widescreen aspect ratio of 16:9, so the 1080 lines of vertical resolution implies 1920 columns of horizontal resolution, or 1920 pixels × 1080 lines. A 1920 pixels × 1080 lines screen has a total of 2.1 megapixels and a temporal resolution of 50 or 60 interlaced fields per second. This format is used in the SMPTE 292M standard; the choice of 1080 lines originates with Charles Poynton, who in the early 1990s pushed for "square pixels" to be used in HD video formats. Within the designation "1080i", the i stands for interlaced scan. A frame of 1080i video consists of two sequential fields of 540 vertical pixels; the first field consists of all odd-numbered TV lines and the second all numbered lines.

The horizontal lines of pixels in each field are captured and displayed with a one-line vertical gap between them, so the lines of the next field can be interlaced between them, resulting in 1080 total lines. 1080i differs from 1080p, where the p stands for progressive scan, where all lines in a frame are captured at the same time. In native or pure 1080i, the two fields of a frame correspond to different instants, so motion portrayal is good; this is true for interlaced video in general and can be observed in still images taken of fast motion scenes. However, when 1080p material is captured at 25 or 30 frames/second, it is converted to 1080i at 50 or 60 fields/second for processing or broadcasting. In this situation both fields in a frame do correspond to the same instant; the field-to-instant relation is somewhat more complex for the case of 1080p at 24 frames/second converted to 1080i at 60 fields/second. The field rate of 1080i is 60 Hz for countries that use or used System M as analog television system with 60 fields/sec, or 50 Hz for regions that use or used 625-lines television system with 50 fields/sec.

Both field rates can be carried by major digital television broadcast formats such as ATSC, DVB, ISDB-T International. The frame rate can be implied by the context, while the field rate is specified after the letter i, such as "1080i60". In this case 1080i60 refers to 60 fields per second; the European Broadcasting Union prefers to use the resolution and frame rate separated by a slash, as in 1080i/30 and 1080i/25 480i/30 and 576i/25. Resolutions of 1080i60 or 1080i50 refers to 1080i/30 or 1080i/25 in EBU notation. 1080i is directly compatible with some CRT HDTVs on which it can be displayed natively in interlaced form, but for display on progressive-scan—e.g. Most new LCD and plasma TVs, it must be deinterlaced. Depending on the television's video processing capabilities, the resulting video quality may vary, but may not suffer. For example, film material at 25fps may be deinterlaced from 1080i50 to restore a full 1080p resolution at the original frame rate without any loss. Preferably video material with 50 or 60 motion phases/second is to be converted to 50p or 60p before display.

Worldwide, most HD channels on satellite and cable broadcast in 1080i. In the United States, 1080i is the preferred format for most broadcasters, with Inc.. Viacom, AT&T, andComcast owned networks broadcasting in the format, along with most smaller broadcasters. Only Fox- and Disney-owned television networks, along with MLB Network and a few other cable networks, use 720p as the preferred format for their networks. Many ABC affiliates owned by Hearst Television and former Belo Corporation stations owned by TEGNA, along with some individual affiliates of those three networks, air their signals in 1080i and upscale network programming for master control and transmission purposes, as most syndicated programming and advertising is produced and distributed in 1080i/p, removing a downscaling step to 720p; this allows local newscasts on these ABC affiliates to be produced in the higher resolution to match the picture quality of their 1080i competitors. Some cameras and broadcast systems that use 1080 vertical lines per frame do not use the full 1920 pixels of a nominal 1080i picture for image capture and encoding.

Common subsampling ratios include 3/4 and 1/2. Where used, the lower horizontal resolution is scaled to display a full-sized picture. Using half horizontal resolution and only one field of each frame results in the format known as qHD, which has frame resolution 960x540 a

Hildesheim–Brunswick railway

The Hildesheim–Brunswick line is a 43 km long electrified main line railway in the German state of Lower Saxony. It forms part of the Intercity-Express route from Frankfurt to Berlin, it is used as a diversion route from the Hanover–Brunswick line. It is a single track line from Hildesheim to Groß Gleidingen. A proposal to duplicate the line was included in the Federal Transport Infrastructure Plan of 1992; the first railways were opened to Brunswick in the 1840s. A direct connection across the former border between the Kingdom of Hanover and the Duchy of Brunswick was, not desired, at least in Hanover. East-west traffic ran through Kreiensen. Hildesheim was only connected via Lehrte in the north and with a branch line to Nordstemmen station on the Hanoverian Southern Railway. After the annexation of Hanover by Prussia after the War of 1866, this situation changed; the Hanover-Altenbeken Railway Company built the Elze–Löhne line in 1875 and connected it with the Hildesheim–Goslar line to the southeast.

This meant. It only needed a direct connection to Brunswick to cope with increasing levels of traffic from the iron ore mines in the northern Harz district. In 1888 the 35 km long link between Hildesheim to the Hanover–Brunswick line at Gross Gleidingen was put into operation; the railway was only a secondary line. It does not lead to the major nearby city of Hanover and, until 1960, the old Brunswick station, built as a terminus, inhibited through traffic. From 1945, the Inner German border blocked most traffic to the east of Brunswick. With the construction of the Hanover–Würzburg high-speed line and the Hildesheim loop built to connect it to Hildesheim and Brunswick from the south, InterCity trains began to run from Frankfurt via Göttingen, Hildesheim and Magdeburg to Berlin in 1991; these were replaced by Intercity-Express trains in 1993 and since 1998 they have taken the route east of Brunswick via the Weddel loop and Hanover–Berlin high-speed line. The section from Hildesheim to Hoheneggelsen was opened on 16 August 1888 and this was followed by the rest of the line to Groß Gleidingen so that the 35 kilometre-long connection from Hildesheim on the Hannover–Brunswick railway could be used throughout on 1 February 1889.

Four years the first German Durchgangszug ran over the line, the D 31/32 between Cologne and Berlin, since it formed part of the shortest route. The line was still a secondary railway, it did not directly connect with Hanover and until 1960 the old Brunswick station was a terminus, which discouraged through traffic. The establishment of the inner German border blocked most of the traffic from Brunswick to the east from 1945. Electrical operations commenced on the line on 25 May 1976. With the construction of the Hanover–Würzburg high-speed railway, the Hildesheim loop was built to connect Hildesheim and Brunswick to the south. From 1991, IC trains ran from Frankfurt via Göttingen, Hildesheim and Magdeburg to Berlin; these were replaced in 1993 by ICE services. The single-track operation proved to be vulnerable to delays. In the Federal Transport Infrastructure Plan of 1992 and its successor, the Federal Transport Infrastructure Plan of 2003 included an upgraded Löhne–Hamelin–Hildesheim–Brunswick route, inter alia, the duplication of the whole line, completed in 2012.

The section between Hildesheim and Groß Gleidingen was closed for renovation between June 20 and 12 September 2002. In the spring of 2000, the Federal Ministry of Transport examined plans to upgrade the Brunswick–Hamelin–Löhne axis for double track as a southern bypass of the node of Hanover for freight traffic; the route was planned to become the main axis for goods traffic running east-west. A decision on the plan was expected by 2002; the planning approvals for the three sections of double tracking with a total length of 34 km were issued on 14 November 2001, 12 December 2001 and 24 February 2002. The financing of the project was resolved at the end of 2007; the federal government would provide €80 million and the state would provide the other €40 million. It was planned to raise the maximum speed of the line to 160 km/h instead of the previous 140 km/h. In January 2009, the federal government announced it would fund €131 million of a total investment of 139 million. Construction would begin in the summer of 2009 and be completed by the end of 2012.

In addition, the state of Lower Saxony and Deutsche Bahn would provide part of the funding. In mid-December 2008, Deutsche Bahn notified that it would be calling tenders for the doubling over a length of 34 kilometres; the project package was valued at a total of €100 million. On 20 January 2009, the financial agreement for the upgrade was finalised; the symbolic groundbreaking ceremony took place on 23 January 2009. However, Deutsche Bahn did not call tenders until mid-July 2009, with the contract to be awarded from November 2009 and work to be completed by the end of December 2012. Work began on 18 January 2010; the total cost of the upgrade was now stated to be €140 million. The section between Hildesheim and Hoheneggelsen was put into operation in October 2011; the second section was formally opened on 5 November 2012. The federal government's share of the costs was reported as €137 million. After the completion of the remaining work, two-track operations commenced at the timetable change on 9 December 2012.

By eliminating waiting times and the higher line speed, the travel time for local t

Prairie and Arctic Storm Prediction Centre

The Prairie and Arctic Storm Prediction Centre, is tasked with forecasting weather for the public and mariners in the Canadian Prairie Provinces, the Northwest Territories, Nunavut Territory, adjacent domestic waters. The PASPC has its operations split between an office in Winnipeg, Manitoba and an office in Edmonton, Alberta; the agency provides continuous weather monitoring and issues weather forecasts, weather warnings and weather watches as a part of this process. Daily severe weather discussions are issued to give additional information on a region, becoming a severe weather threat, stating whether a watch or warning is and details thereof; the agency is one of five weather forecast centres for the Meteorological Service of Canada. The other four weather centres are the Pacific and Yukon Storm Prediction Centre, the Ontario Storm Prediction Centre, the Quebec Storm Prediction Centre, the Atlantic Storm Prediction Centre; the Atlantic Storm Prediction Centre houses the Canadian Hurricane Centre plus manages the Newfoundland and Labrador Weather Office.

Each storm prediction centre provides continuous public and marine forecasts and warnings for various parts of Canada's sovereign territory. Aviation weather forecasts are produced separately by the two offices of the Canadian Meteorological Aviation Centre; the PASPC has the largest forecast area of responsibility among the five Storm Prediction Centres, covering a region greater than the other four offices combined. The Prairie and Arctic Storm Prediction Center is part of the Meteorological Service of Canada, operating under the control of the Canadian federal department of Environment and Climate Change Canada; the Prairie and Arctic Storm Prediction was created in 2003. Prior to that, weather forecasting for the Canadian Prairies and the Canadian Arctic had evolved over the previous century; the PASPC's creation was the culmination of decades of transition within the Canadian weather service during this period. The Meteorological Service of Canada was founded in 1871; the first forecasts were prepared in 1887 from Toronto.

These forecasts were for marine interests along the Canadian Atlantic coast and the Great Lakes. As the observing and telegraph networks expanded westward to the Prairie provinces, regular forecasts southern Manitoba were established in 1899 and for Alberta and Saskatchewan in 1903. By this time, a second weather forecast had opened in Victoria, British Columbia but only produced forecasts for that province; the number of forecast offices, including one in Winnipeg, expanded in the late 1930s to support Trans-Canada Airlines, established in 1937. During the war, additional weather centres, including ones in Edmonton, Lethbridge, CFB Rivers, were added in support of Canadian civilian aviation and military operations; the Winnipeg office provided some basic forecasts for the Canadian public in the Prairies. The Lethbridge office provided "storm forecasts" for parts of southern Alberta. After the war, the public weather forecast system, still being done out of Toronto for all of Canada east of the Rockies, was decentralized.

Regional forecast centres were established in 1946 in Vancouver, Winnipeg, Toronto and Halifax. The Edmonton office was responsible for Alberta and the western half of Saskatchewan, while the Winnipeg office was now responsible for eastern Saskatchewan and Northwestern Ontario; the advent of numerical weather prediction in the early 1960s changed the forecasting system in Canada to one of large regional forecast centres, called "Weather Centrals", with local support offices called "Weather Offices". For the Canadian prairie provinces and the arctic territories, the Prairie Weather Central was established in Winnipeg by 1967; the smaller Weather Offices in support of the Prairie Weather Central included Edmonton and Regina, Saskatchewan. In 1971, the weather service was moved to a new Federal Department; the Weather Centrals became "Weather Centres". The newly renamed Prairie Weather Centre still operated out of Winnipeg and its area of responsibility was the provinces of Saskatchewan and Manitoba and Northwestern Ontario.

In Edmonton, the forecast responsibilities were expanded to two new co-located weather offices: the Arctic Weather Centre and the Alberta Weather Centre. Forecasts for the Yukon were now formally provided by the Yukon Weather Office; the Regina Weather Office remained open but was closed in 1979. In 1993 and 1994, the Canadian weather service consolidated its 54 smaller weather briefing offices and eight weather centres into 17 new "Environmental Services Centres"; the Prairie Weather Centre was broken up into the Saskatchewan Environmental Services Centre, based in Saskatoon, the Manitoba Environmental Services Centre in Winnipeg and the Northwestern Ontario Environmental Services Centre in Thunder Bay. The Alberta Weather Centre was split into the Northern Alberta Environmental Services Centre in Edmonton and the Southern Alberta Environmental Services Centre is Calgary. Arctic weather forecasting continued to be done out of Arctic Weather Centre in Edmonton and the Yukon Weather office. In 1998, the Edmonton, Calgary and Winnipeg offices were consolidated into the new Prairie Storm Prediction Centre based in Winnipeg.

The new office was responsible for all public and marine forecasts an