Re: (GIS-L) RE: MI Transverse Mercator Projection
The new Datum "Geocentric Datum of Australia 1994" uses the GRS80 Ellipsoid, and is based on ITRF 1992 Epoch 1994.0. The rest of the parameter swill not change to calc grid coordinates. If you want to call me sometime Paul, I am in Perth, at work on 08 9322 4955 and will help you with anything I can. Mal Jones Email: [EMAIL PROTECTED] - Original Message - From: Clifford J. Mugnier [EMAIL PROTECTED] To: [EMAIL PROTECTED]; [EMAIL PROTECTED] Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED] Sent: Friday, February 11, 2000 5:07 AM Subject: (GIS-L) RE: MI Transverse Mercator Projection - The Integrated Survey Grid (ISG) is used in New South Wales. That as well as all other Grids I have ever heard of being used in Australia since WWII have been Gauss-Kruger Transverse Mercator Grids. The ISG Central Meridians are every two degrees starting at 141* East and continue through 153* East. Scale Factor at Origin is 0.4, the False Easting is 300 Km, and the False Northing is 5,000,000 meters at the Equator. These parameters are for the Australian Geodetic Datum of 1966 (AGD66). I do not know offhand (I am home while writing this; I'm not at the Lab), what the current parameters are for the new Datum. Clifford J. Mugnier ([EMAIL PROTECTED]) The Topographic Engineering Laboratory Department of Civil and Environmental Engineering UNIVERSITY OF NEW ORLEANS New Orleans, Louisiana 70148 Voice and Facsimilie: (504) 280-7095 On Thursday, 10 February, 2000 3:33 PM, Paul Grambauer [SMTP:[EMAIL PROTECTED]] wrote: G'Day, I'm trying to import a DXF file into MapInfo that is provided in a Transverse Mercator Projection for New South Wales, Australia the coordinate units are in metres. Does anybody know the MapInfo equivalent projection, or the correct parameters for entry into the MapInfo projection file. Any thoughts from MapInfo Australia ? Thanks in advance, Paul Grambauer Cessnock City Council PO Box 152, 68-72 Vincent St, Cessnock, 2325 Phone : +61 02 49934192 Fax : +61 02 49934200 Email : [EMAIL PROTECTED] -- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED] +--+ subscribe +- GIS-L -+ unsubscribe +-+ send email To: [EMAIL PROTECTED] | send email To: [EMAIL PROTECTED] In the BODY, type: SUBSCRIBE GIS-L | In the BODY, type: UNSUBSCRIBE GIS-L +--+ + Digest version: GIS-L-DIGEST+ Use the same method to subscribe + +--+ a service of GeoGraph International Corporation (http://www.geoint.com) -- To unsubscribe from this list, send e-mail to [EMAIL PROTECTED] and put "unsubscribe MAPINFO-L" in the message body, or contact [EMAIL PROTECTED]
MI Re: Sri Lanka National Grid System
Gentlemen I have a couple of station descriptions in my possession and a report, both with details on 2 stations in the Port Area of Colombo. One of the stations is as below. I do not know if the WGS 84 UTM coordinates are of any use to anyone, they are just part of my output. Mal Jones Below is best viewed in a non proportional font. FUGRO SURVEY - GEO Version 2.38.01 GEODESY 1 Datum : Kandawala Spheroid : Everest 1830C Semi Major Axis : 6377276.345 m Inverse Flattening: 300.80170 Projection: Transverse Mercator (UTM) Latitude Origin :7ø 00' 01.7290" N Longitude Origin : 80ø 46' 18.1600" E False Easting : 20.000 m False Northing: 20.000 m Central Scale Factor : 0.238418 GEODESY 2 Datum : WGS 84 Spheroid : WGS 84 Semi Major Axis : 6378137.000 m Inverse Flattening: 298.257223563 Projection: Transverse Mercator (UTM) Latitude Origin :0ø 00' 00." N Longitude Origin : 81ø 00' 00." E False Easting : 50.000 m False Northing:0.000 m Central Scale Factor : 0.999600 PARAMETERS FOR CONVERSION FROM WGS 84 Kandawala WGS 84 Geod 1 to Geod 2 dX: 98.300 m 0.000 m-98.300 m dY: -787.500 m 0.000 m787.500 m dZ: -85.000 m 0.000 m 85.000 m rX:0. " 0. " 0. " rY:0. " 0. " 0. " rZ:0. " 0. " 0. " dS:1.0 ppm0.0 ppm -1.0 ppm TRANSFORMATIONS Station Name: PW-5 Datum : Kandawala: WGS 84 Projection : Transverse Mercator : Transverse Mercator Latitude:6ø 57' 09.3865" N :6ø 57' 10.5800" N Longitude : 79ø 50' 37.0926" E : 79ø 50' 44.7687" E Height :8.097 m: -93.704 m Easting :97459.221 m: 372492.852 m Northing: 194807.060 m: 768701.916 m PSF : 1.539617 : 0.9998012206 Convergence : - 0ø 06' 44.47" : - 0ø 08' 23.08" - Original Message - From: Cliff Mugnier - University of New Orleans [EMAIL PROTECTED] To: [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED] Sent: Friday, September 10, 1999 6:08 AM Subject: GPS: Sri Lanka National Grid System John, The Kandawala Datum of 1929 origin is at Latitude = 7* 14' 06.838" North, Longitude = 79* 52' 36.670" East of Greenwich. The reference azimuth to station Halgastota = 176* 41' 33.18", and the ellipsoid of reference is the Everest 1830 where a = 6,377,276.345 meters and first eccentricity squared is 0.00663784663020. The scale of the triangulation of the island is dependant on two bases, each about 5 1/2 miles long, situated at Negombo on the West Coast (Latitude 7* 10'), and at Batticaloa on the East Coast (Latitude 7* 40') These bases were originally measured in 1857 and 1859 respectively, remeasured in 1930. The bases agree to 1 in 115,000. The National Grid System is the Ceylon (Sir Lanka) Transverse Mercator Belt which is based on the abbreviated Gauss-Kruger (truncated at the fifth derivative term). The Central Meridian is 80* 46' 18.16" East, The False Northing Latitude of Origin is 7* 00' 01.7290" North, the Scale Factor at Origin is unity, and both the false northings and false eastings are 176,000 Indian Yards where one meter is equal to 1.093619000 Indian Yards. The International Boundary between Sri Lanka is much simpler than that of Norway. Your country uses the Principle of Straight Baselines, but the Sri Lankans use "Great Circle Arcs" (ellipsoidal geodesics) to define their limits with coordinate points that are expressed in Latitude and Longitude. Check out the website for the American Society for Photogrammetry and Remote Sensing at http://www.asprs.org/resources.html Under the heading of "Grids and Datums" are a number of my past columns on various countries, Norway will be the featured country next month (October, 1999). Cliff Mugnier -- Clifford J. Mugnier ([EMAIL PROTECTED]) The Topographic Engineering Laboratory Department of Civil and Environmental Engineering UNIVERSITY OF NEW ORLEANS New Orleans, Louisiana 70148 Voice and Facsimile: (504) 280-7095 - Dehls John wrote: Does anyone know the details of the Sri Lankan
MI RE: Flavours of Transverse Mercator
The bible reference for all TM usage today is: Redfearn J C B (1948), Transverse Mercator Formulae, Empire Survey Review, Vol IX, No 69, July, P 318-322. It is just formulas, without integrals or differentials, and so easy to understand. Suggest you get a copy of this paper. Mal Jones (Geodesy Jones) 89 Woodhall St, Stirling WA 6021, Australia Tel: +61 8 9344 5232 Email: [EMAIL PROTECTED] -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Cliff Mugnier - University of New Orleans Sent: Friday, 23 July 1999 03:46 To: [EMAIL PROTECTED] Cc: [EMAIL PROTECTED]; [EMAIL PROTECTED]; [EMAIL PROTECTED] Subject: GPS: Flavors of Transverse Mercator Fernando, The GCTP.FOR is a Fortran77 source file (free from the "USGS.gov" websites) for all of the map projections used by the U.S. Geological Survey. There are two data files associated with the source code that are included also. The math was documented by John P. Snyder (now deceased) in "Map Projections Used by the U.S. Geological Survey" Bulletin 1532, and later revised as "Map Projections - A Working Manual" Bulletin 1535. Bulletin 1535 is better because it has more projections and Mr. Snyder referenced me (ha, ha)! :-) Anyway, Dr. Atef Elassal (now retired), then translated 1532 into Fortran for the USGS. That is GCTP - the General Cartographic Transformation Package which is specifically for cartographic applications within the United States. That's what the data files are for. GCTP is absolutely perfect for what it was intended for - INSIDE THE UNITED STATES OF AMERICA ONLY ! ! ! ! ! Many, many commercial software packages worldwide use this as the basic foundation for their coordinate transformation engine. I give it away to my students as an example of "how not to do it." This is essentially useless for geodetic applications outside of the United States. It can oftentimes be used for cartographic applications outside of the U.S. IF AND ONLY IF the computational accuracy (and precision) is not needed for mapping at scales larger than 1:24,000!!! If you are going to use this for a NON-geodetic application, this will do just fine. If you are doing geodesy, do not touch this code! -- The ellipsoidal case of the Transverse Mercator was cooked up by Heinrich Lambert in the middle 1700's. It was a mathematical curiousity that was useless for practical applications until the City of Hannover asked Professor Carl Freiderich Gauss to do a geodetic survey of the city in preparation for a new set of accurate tax maps. There are two things you cannot avoid in life; those are death and taxes. Most all geodetic research has been funded (since the late 1700's) for either tax mapping purposes or military purposes looking for better and more efficient ways of killing people ... Anyway, Gauss worked up an expansion of Lambert's formulae that his Ph.D. students could follow in doing the grunt work of adjusting the Hannover Triangulation Net on the Gauss-Conformal Transverse Mercator. Years later, a Prussian Artillery Office named Schreiber used a simplified form of the Gauss-Conformal Transverse Mercator that was a specific truncation called the Gauss-Schreiber Transverse Mercator. Another Prussian Artillery Officer named Krüger came up with a more elaborate expansion of the infinite series. Yup, it is called the Gauss-Krüger Transverse Mercator. In the 1920's or 1930's an Italian Professor in Italy came up with a local version for the Instituto Geografico Militare, and his name was Boaga. Yup, the Italians use the Gauss-Boaga Transverse Mercator. And so on and so forth for ALL the ellipsoidal projections used for Grids on topographic maps. When looking at geodetic accuracy and computational precision at the sub-millimeter level TO THE MULTI-METER LEVEL for coordinates many degrees east or west of the central meridian, the specific truncation of a Transverse Mercator makes a big difference. Doing foreign work for bazillion-dollar exploration, drilling, and production for oil wells in specific countries? Pay attention to your math. If you are doing UTM or DHG (Deutches Herres Gitter) within a plus or minus 3 degree longitude distance from the Central Meridian, it will do fine. Diddling with some X,Y coordinates for a Ph. D. dissertation? Unless your Major Professor is a geodesist or mathematical cartographer, they won't even know the difference. Cliff -- Clifford J. Mugnier ([EMAIL PROTECTED]) The Topographic Engineering Laboratory Department of Civil and Environmental Engineering UNIVERSITY OF NEW ORLEANS New Orleans, Louisiana 70148 Voice and Facsimile: (504) 280-7095 --- Fernando wrote: Hello Cliff I am doctorate student that needs to program a convert from Gauss Krüger to lat. long and back. The ideal solution would be to get a Fortran code for this, but maybe that
