Milestone-Proposal:LORAN: Difference between revisions
From ETHW
(Article updated via HTTP request) |
(Article updated via HTTP request) |
||
| Line 1: | Line 1: | ||
{{ProposalEdit|a1=LORAN|a2a=Cambridge MA|a2b=Boston Section|a3=1940 to 1946|a4=LORAN is a hyperbolic system of navigation by which difference in distance from two points on shore is determined by measurement of the time interval between reception of pulse- modulated synchronized signals from transmitters at the two points. The name LORAN is derived from long-range navigation. Since it operates in the 1,750 to 1,950 kc frequency range, both ground waves and sky waves can be used to to provide coverage over an extensive area with few stations. An important advantage of loran during the WW2 was that a ship could use loran without breaking radio silence. Loran transmitting stations work in pairs. Synchronization is achieved by letting the signals of the Master station, control those of the Slave station. To help overcome the disadvantage of requiring two transmitting stations for a single family of hyperbolic lines of positions, loran forms a chain of stations, so that each station except the end ones operate with the station on either side to form an intersecting lattice of position lines. | {{ProposalEdit|a1=LORAN|a2a=Cambridge MA|a2b=Boston Section|a3=1940 to 1946|a4=LORAN is a hyperbolic system of navigation by which difference in distance from two points on shore is determined by measurement of the time interval between reception of pulse- modulated synchronized signals from transmitters at the two points. The name LORAN is derived from long-range navigation. Since it operates in the 1,750 to 1,950 kc frequency range, both ground waves and sky waves can be used to to provide coverage over an extensive area with few stations. An important advantage of loran during the WW2 was that a ship could use loran without breaking radio silence. Loran transmitting stations work in pairs. Synchronization is achieved by letting the signals of the Master station, control those of the Slave station. To help overcome the disadvantage of requiring two transmitting stations for a single family of hyperbolic lines of positions, loran forms a chain of stations, so that each station except the end ones operate with the station on either side to form an intersecting lattice of position lines. | ||
Loran consist of three components: 1. a chain of radio transmitters in operations 24/7 to create an electronic lattice or grid upon the surface of the earth. 2. a loran receiver-indicator in each ship or aircraft and 3. loran nautical and aeronautical charts or tables published by the US Navy Hydrographic Office. A simple explanation of how loran works can be found is section on loran as an Attachment named "American Practical Navigator" | Loran consist of three components: 1. a chain of radio transmitters in operations 24/7 to create an electronic lattice or grid upon the surface of the earth. 2. a loran receiver-indicator in each ship or aircraft and 3. loran nautical and aeronautical charts or tables published by the US Navy Hydrographic Office. A simple explanation of how loran works can be found is section on loran as an Attachment named "American Practical Navigator" | ||
INSERT OR REFER TO DOC.. | INSERT OR REFER TO DOC.. | ||
Each ship or bomber required a radio receiver- indicator, something like a electronic stopwatch but with a cathode ray tube, timing circuits, etc. The third system component was Loran charts or tables wasThen the navigator | Each ship or bomber required a radio receiver- indicator, something like a electronic stopwatch but with a cathode ray tube, timing circuits, etc. The third system component was Loran charts or tables wasThen the navigator | ||
shipboard navigators | shipboard navigators | ||
BRIEF DESCRIPTION | |||
201O. Lorrtn.-i%andard Loran isahyperbolicsystem that wasdevel- oped primarily for navigationover water. It operateson one ofseveral frequenciesbetween1700and 2000 kc/seeand thereforeenjoyspropaga- tion characteristics determined primarily bysoilconductivity and ionospheric conditions. Transmittersnowin use radiateabout100kw and give a ground-waverange oversea waterofabout700 nauticalmiles in the daytime. The daytimerange over land isseldommore than 250 miles evenfor high-flyingaircraftand is scarcely100miles at the surface of the earth.At nightthe ground-waverange oversea water isreduced to about500 miles by the increase in atmosphericnoise,but sky waves, which arealmost completelyabsorbed byday,become effective and increase the reliablenightrange to about1400miles. | |||
HISTORY - USE POINT TO USCG | HISTORY - USE POINT TO USCG | ||
The following paragraphs tell the story of Loran's beginning, its first leaders, location where the work was performed, the installation of the first | The following paragraphs tell the story of Loran's beginning, its first leaders, location where the work was performed, the installation of the first | ||
Engineering is not a solo activity. When a grande long-lived engineered system like LORAN, .. this nomination milestone gives credit to those persons that worked on the so-called Project 3 or C of the Radiation Laboratory of MIT during 1941 to c1946. This group of individuals did not work in the Rad Lab building, having nothing to do with microwave or radar. These individuals work in the Hood Building and other building in Boston and Cambridge. The USCG had a permanent office working on this project. One person in particular that deserves mention is Coast Guard Lt. Cmdr. L.M. Harding who provided supervision and direction for the Pacific Loran ... | Engineering is not a solo activity. When a grande long-lived engineered system like LORAN, .. this nomination milestone gives credit to those persons that worked on the so-called Project 3 or C of the Radiation Laboratory of MIT during 1941 to c1946. This group of individuals did not work in the Rad Lab building, having nothing to do with microwave or radar. These individuals work in the Hood Building and other building in Boston and Cambridge. The USCG had a permanent office working on this project. One person in particular that deserves mention is Coast Guard Lt. Cmdr. L.M. Harding who provided supervision and direction for the Pacific Loran ... | ||
| Line 50: | Line 50: | ||
The Coast Guard published a Federal Register notice on Jan. 7, 2010, regarding its intention to terminate transmission of the LORAN-C signal Feb. 8, 2010. A LORAN Programmatic Environmental Impact Statement Record of Decision stating that the environmentally preferred alternative is to decommission the LORAN-C Program and terminate the North American LORAN-C signal was http://www.navcen.uscg.gov/loran/default.htmpublished in the Federal Register on Jan. 7, 2010.
| The Coast Guard published a Federal Register notice on Jan. 7, 2010, regarding its intention to terminate transmission of the LORAN-C signal Feb. 8, 2010. A LORAN Programmatic Environmental Impact Statement Record of Decision stating that the environmentally preferred alternative is to decommission the LORAN-C Program and terminate the North American LORAN-C signal was http://www.navcen.uscg.gov/loran/default.htmpublished in the Federal Register on Jan. 7, 2010.
| ||
USCG announces LORAN-C termination | USCG announces LORAN-C termination | ||
REFERENCES | REFERENCES | ||
JA Pierce, "An Introduction to Loran", IEEE AES Magazine 1990 (attached) | JA Pierce, "An Introduction to Loran", IEEE AES Magazine 1990 (attached) | ||
| Line 64: | Line 62: | ||
http://www.uscg.mil/History/STATIONS/LORAN_Section_1.asp | http://www.uscg.mil/History/STATIONS/LORAN_Section_1.asp | ||
http://www.scribd.com/doc/35814242/MIT-Radiation-Lab-Series-V2-Radar-Aids-to-Navigation | http://www.scribd.com/doc/35814242/MIT-Radiation-Lab-Series-V2-Radar-Aids-to-Navigation | ||
TO PROBE FURTHER | TO PROBE FURTHER | ||
I. B.W. Sittelry, “ELEMENTS OFLORAN,” MIT Radiation Laboratoyr Re- port No. 499; March, 1944; also available as Navships 900, 027, Bureau of Ships, April 1944 | I. B.W. Sittelry, “ELEMENTS OFLORAN,” MIT Radiation Laboratoyr Re- port No. 499; March, 1944; also available as Navships 900, 027, Bureau of Ships, April 1944 | ||
| Line 74: | Line 71: | ||
7. Alexander A. McKenzie, “LORAN-THE LATEST IN NAVIGATIONAL AIDS,” QST, Part I , vol. 29. pp. 12-16. December, 1945; part 2. vol. 30, pp. 54-57. January, 1946; part 3, vol. 30, pp, 62-65, February, 1946 | 7. Alexander A. McKenzie, “LORAN-THE LATEST IN NAVIGATIONAL AIDS,” QST, Part I , vol. 29. pp. 12-16. December, 1945; part 2. vol. 30, pp. 54-57. January, 1946; part 3, vol. 30, pp, 62-65, February, 1946 | ||
_|a5=The speed in which the LORAN system of navigation was initially designed, developed, constructed, placed into operations, manned 24/7 by radio technicians at isolated regions of the globe, is hard to explain. Even for a well-funded wartime crash program. Authors of this milestone proposal are not aware of anything similar to loran. | |||
The proposal covers the time period between 1940 to 1946, i.e. the very beginning of loran. That period was especially awesome, noteworthy. | The proposal covers the time period between 1940 to 1946, i.e. the very beginning of loran. That period was especially awesome, noteworthy. | ||
Offer the following websites can explain history ..history | Offer the following websites can explain history ..history | ||
Revision as of 21:54, 9 December 2010
This Proposal has not been submitted and may only be edited by the original author.
Pierce Loran.pdf
