VERLORT Radar
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| The '''VER'''y '''LO'''ng '''R'''ange '''T'''racking (VERLORT) S-band radar (2700 t0 2900 MHz) was an extended-range version of the '''SCR-584''' - often credited as "the radar that won WW II". | The '''VER'''y '''LO'''ng '''R'''ange '''T'''racking (VERLORT) S-band radar (2700 t0 2900 MHz) was an extended-range version of the '''SCR-584''' - often credited as "the radar that won WW II". | ||
| - | For Mercury, the radar range was increased from 650 Km to 4000 Km; the dish diameter from 1.8 m to 3 m and it was given a long name befitting its new space-tracking capabilities. The Red Lake (Woomera) Mercury tracking station used the more accurate AN/FPS-16 radar installed at Woomera for previous space activities. | + | For space missions, its range was increased from 650 Km to 4000 Km; the dish diameter from 1.8 m to 3 m and it was given a long name befitting its new space-tracking capabilities. The Red Lake (Woomera) Mercury tracking station used the more accurate AN/FPS-16 radar installed at Woomera for previous space activities. |
| [[Image:cro-verlort.jpg|left|thumbnail|180px|The VERLORT radar reinstalled at Carnarvon just beside the AcqAid antennas:<BR>''Photo - Alan Gilham'']] | [[Image:cro-verlort.jpg|left|thumbnail|180px|The VERLORT radar reinstalled at Carnarvon just beside the AcqAid antennas:<BR>''Photo - Alan Gilham'']] | ||
| - | The Verlort radar performed reliably for the six Mercury orbital missions at Muchea. It was then relocated to the new Gemini tracking station at Carnarvon as an acquisition aid and back-up for the even more accurate FPQ-6 radar to be installed there. | + | The Verlort performed reliably for the six Mercury orbital missions at Muchea. It was then relocated to the new Gemini tracking station at Carnarvon as an acquisition aid and back-up for the even more accurate FPQ-6 radar to be installed there. |
| - | Although the Verlort was kept operational at Carnarvon for the first few missions it was soon operationally delisted once the FPQ-6 proved its reliablility and other acquisition methods also proved sufficient. | + | Although the Verlort was kept operational at Carnarvon for the first few missions it was soon taken off the operational list once the FPQ-6 proved its reliability and other acquisition methods also proved sufficient. |
| - | ==Some technical descriptions== | + | ==Some innovative mechanical solutions== |
| [[Image:Helical scan.jpg|right|thumbnail|180px|Helical scan mechanism:<BR>''Image – ‘Electronics’; Fig 2, Dec ’45, p.104'']] | [[Image:Helical scan.jpg|right|thumbnail|180px|Helical scan mechanism:<BR>''Image – ‘Electronics’; Fig 2, Dec ’45, p.104'']] | ||
| - | The SCR family of radars, developed at the MIT laboratories, was remarkable for the innovative MIT solutions to radar operations that are now met in modern radars by electronic methods. | + | The SCR radars, developed at the MIT laboratories, were remarkable for MIT’s innovative mechanical solutions to radar operations that are now met by electronic methods in modern radars. |
| - | The '''Verlort Plan Position Indicator (PPI)''' was driven by a '''mechanical''' computer. Once target acquisition occurred, the radar operator needed to keep a ‘hairline’ indicator manually centred on the target’s echo to maintain track. | + | The Verlort '''Plan Position Indicator''' (PPI) was driven by a '''mechanical''' computer. Once target acquisition occurred, the radar operator needed to keep a ‘hairline’ indicator manually centred on the target’s echo to maintain track. |
| Even more intriguing were the target acquisition techniques. | Even more intriguing were the target acquisition techniques. | ||
| - | For targets where only crude position information was available, a '''helical scan''' was used to acquire the target. The dish was swung in a circle at 6 rpm along the expected path with the reflector tilted to and fro about 4° per dish revolution to create a '''helical spiral''' about 20° wide along the expected track path - see 'Helical scan mechanism' diagram on right. | + | For targets where only crude position information was available, a '''helical scan''' was used to acquire the target. The dish was swung in a circle at 6 rpm along as it moved with the reflector tilting to and fro about 4° per dish revolution to create a '''helical spiral''' about 20° wide along the expected track path - see 'Helical scan mechanism' diagram on right. |
| - | Where there was more certainty about the target path, a '''nutating scan''' mode was used where the slightly offset dipole feed was rotated rapidly to produce off-axis radiation to increase the effective beam width from 2.5° to about 5.5° . The nutation was switched off when the target was acquired. See ‘conical scan beam’ diagram below left and ‘nutating antenna dipole feed’ below right.<BR> | + | Where there was more certainty about the target path, a '''nutating scan''' mode was used. The slightly offset dipole feed was rotated rapidly to produce off-axis radiation increasing the effective beam width from 2.5° to about 5.5° . Nutation was switched off when the target was acquired. See the ‘conical scan beam’ diagram below left and the ‘nutating antenna dipole feed’ below right. |
| - | + | ||
| - | [[Image:offset dipole.jpg|right|thumbnail|290px|Nutating antenna dipole feed:<BR>''Image – ‘Electronics’; Fig 5, Dec ’45, p.107'']] | + | |
| [[Image:Conical beam.jpg|left|thumbnail|250px|A conical scan beam:<BR> ''Image – ‘Electronics’; Fig 1, Nov ’45, p.104'']] | [[Image:Conical beam.jpg|left|thumbnail|250px|A conical scan beam:<BR> ''Image – ‘Electronics’; Fig 1, Nov ’45, p.104'']] | ||
| + | |||
| + | [[Image:offset dipole.jpg|right|thumbnail|290px|Nutating antenna dipole feed:<BR>''Image – ‘Electronics’; Fig 5, Dec ’45, p.107'']] | ||
| <BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR> | <BR><BR><BR><BR><BR><BR><BR><BR><BR><BR><BR> | ||
| + | |||
| ---- | ---- | ||
| - | For a detailed technical description of the SCR-584 radar see the '''November & December 1945''' issues of '''‘Electronics’''' magazine at http://www.hamhud.net/darts/scr584.html - a celebration of the MIT SCR radar family. | + | For a detailed technical description of the SCR-584 radar see the '''November & December 1945''' issues of '''‘Electronics’''' magazine at http://www.hamhud.net/darts/scr584.html. |
Revision as of 01:45, 9 May 2007
Photo - ???
The VERy LOng Range Tracking (VERLORT) S-band radar (2700 t0 2900 MHz) was an extended-range version of the SCR-584 - often credited as "the radar that won WW II".
For space missions, its range was increased from 650 Km to 4000 Km; the dish diameter from 1.8 m to 3 m and it was given a long name befitting its new space-tracking capabilities. The Red Lake (Woomera) Mercury tracking station used the more accurate AN/FPS-16 radar installed at Woomera for previous space activities.
Photo - Alan Gilham
The Verlort performed reliably for the six Mercury orbital missions at Muchea. It was then relocated to the new Gemini tracking station at Carnarvon as an acquisition aid and back-up for the even more accurate FPQ-6 radar to be installed there.
Although the Verlort was kept operational at Carnarvon for the first few missions it was soon taken off the operational list once the FPQ-6 proved its reliability and other acquisition methods also proved sufficient.
Some innovative mechanical solutions
Image – ‘Electronics’; Fig 2, Dec ’45, p.104
The SCR radars, developed at the MIT laboratories, were remarkable for MIT’s innovative mechanical solutions to radar operations that are now met by electronic methods in modern radars.
The Verlort Plan Position Indicator (PPI) was driven by a mechanical computer. Once target acquisition occurred, the radar operator needed to keep a ‘hairline’ indicator manually centred on the target’s echo to maintain track.
Even more intriguing were the target acquisition techniques.
For targets where only crude position information was available, a helical scan was used to acquire the target. The dish was swung in a circle at 6 rpm along as it moved with the reflector tilting to and fro about 4° per dish revolution to create a helical spiral about 20° wide along the expected track path - see 'Helical scan mechanism' diagram on right.
Where there was more certainty about the target path, a nutating scan mode was used. The slightly offset dipole feed was rotated rapidly to produce off-axis radiation increasing the effective beam width from 2.5° to about 5.5° . Nutation was switched off when the target was acquired. See the ‘conical scan beam’ diagram below left and the ‘nutating antenna dipole feed’ below right.
Image – ‘Electronics’; Fig 1, Nov ’45, p.104
Image – ‘Electronics’; Fig 5, Dec ’45, p.107
For a detailed technical description of the SCR-584 radar see the November & December 1945 issues of ‘Electronics’ magazine at http://www.hamhud.net/darts/scr584.html.
