“Snake Projection”的意思、由来-开放百科全书

The Snake Projection is a coordinate system which projects geographical coordinates onto an easting and northing grid.^[1] The parameters defining the Snake Projection must be tailored for specific projects; the most typical use is with large-scale linear engineering projects such as rail infrastructure, however the projection is equally applicable to any application requiring a low distortion grid along a linear route (e.g. pipelines and roads).^[2] The name of the projection is derived from the sinuous nature of the projects it may be designed for. Typical map projection distance distortion characteristics of a Snake projection are minimal over the whole route within approximately 20 kilometres of the centre line.^[3] The principal advantage of the projection is that, for the corridor defining the design space, distances measured on the ground have a one to one relationship with distances in coordinate space (i.e. no scale factor need be applied to convert between distances in grid and distances on the ground).^[4] The main disadvantage is that away from the design corridor the distortion of the projection is not controlled.

The Snake Projection is the engineering coordinate system used for a significant proportion of primary rail routes in the UK,^[5] including that of the HS2 London to Birmingham line.^[6] For the London to Glasgow West Coast Main Line the distortion in the Snake Projection used is no greater than 20 parts per notation within 5 kilometres of either side of the track.^[7]

References

1. ^{{cite journal|last1=Iliffe|first1=J. C.|last2=Arthur|first2=J. V.|last3=Preston|first3=C.|title=The Snake Projection: A Customised Grid for Rail Projects|journal=Survey Review|date=2007|volume=39|issue=304|page=90–99|doi=10.1179/003962607X165041}}
2. ^{{cite book|last1=Reynolds|first1=John|title=An Introduction to Applied and Environmental Geophysics|date=2011|publisher=John Wiley & Sons|isbn=978-0-471-48535-3|edition=2|url=https://www.wiley.com/en-gb/An+Introduction+to+Applied+and+Environmental+Geophysics%2C+2nd+Edition-p-9780471485353}}
3. ^{{cite journal|last1=Iliffe|first1=J. C.|title=The development and analysis of quasi-linear map projections|journal=Cartography and Geographic Information Science|volume=45|issue=3|pages=270–283|date=2017|doi=10.1080/15230406.2017.1325332|url=http://discovery.ucl.ac.uk/1556463/}}
4. ^{{cite web|last1=SCSI|title=Map Projections and Scale Factor|url=https://www.scsi.ie/documents/get_lob?id=458&field=file#page=5|website=SCSI|publisher=Society of Chartered Surveyors Ireland}}
5. ^{{cite web|last1=XYHT|title=Corridor Projections Solved|url=http://www.xyht.com/professional-surveyor-archives/corridor-projections-solved/|website=XYHT|publisher=Flatdog Media|accessdate=5 February 2018|date=2015-01-15}}
6. ^{{cite web|last1=UCL|title=HS2 becomes fifth project this year to adopt SnakeGrid system|url=https://www.cege.ucl.ac.uk/news-events/Lists/News%20%20Announcements/Announcement/displayifs.aspx?List=55c7dbd4-3027-423f-bfcf-ed525bb40245&ID=121&ContentTypeId=0x010400A41508A6A59B4D45AC85D44B776AC063|website=CEGE|publisher=UCL|accessdate=5 February 2018}}
7. ^{{cite book|last1=Uren|first1=John|last2=Price|first2=Bill|title=Surveying for Engineers|date=2010|publisher=Palgrave Macmillan|location=Basingstoke|edition=5|url=https://www.macmillanihe.com/page/detail/Surveying-for-Engineers/?K=9780230221574}}