Re: A question about Italy Map Projection.
"Max Zhao" <[email protected]> Mon, 7 Jul 2003 14:16:14 -0400
| Newsgroups | gmane.comp.gis.osrs |
|---|---|
| Message-ID | <02e401c344b3$da8c2c00$dcd2cd87@zhaopc> |
This is a multi-part message in MIME format. ------=_NextPart_000_02E1_01C34492.53415390 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Jerry, Thanks a lot for your help. The information you provided is very = convincing! Also I did a rough calculation about range: major radius of earth =3D 6378388 (m). So the circumstance = of the maximum circle is: 2*pi*radius. And the maximal span for 3 degree = is: 2*pi*radius* 3/360 =3D 333971.61. Therefore starting from longitude = of 9 and going eastward, the maximal easting for 12 deg should not be = larger than 1833971.61m. If we go from 15 deg toward 12 deg in the east = zone. The easting for 12 deg will be 2520000 - 333971.61 =3D 2186028.39. So the two zones should = not intersect. I tried my program on the set of (E,N) data I have. Then I found a = problem. The eastings I got have some positive and negative values. The = boundary part looks like at longitude of 12.50 deg. So I suspect that = the system uses only one set of datum (one FALSE Easting and Northing) at = Monte Mario (Rome). I revised my program to set: FALSE northing=3D0, FALSE easting=3D0=20 latitude of natural origin =3D 12.50 deg, longitude of natural origin =3D 0 deg. It is kind of weird that a grid system have negative values. So I guess = I really need to get back to our data source to find out what is the = conversion method they use. Thank you all for your help. -------------------------------------------------------------------------= ----------------------------- Max Zhao RM2D15, Building104 Florham Park, NJ07932 Phone: (973) 236-6493 Fax: (973) 236-6679 -------------------------------------------------------------------------= ----------------------------- ----- Original Message -----=20 From: Jerry Helfand=20 To: [email protected]=20 Sent: Friday, July 04, 2003 1:00 AM Subject: Re: [OSRS] A question about Italy Map Projection. Max, More info (kids are asleep and aimless web surfing seems, well, = aimless...) : From website: http://www.opengis.org/techno/interop/EPSG2WKT.TXT = which I got from a HOTBOT search on "italy map system zone central = meridian":=20 (Todd Jamison is right. Zone 1 Eastings will not overlap Zone 2 = Eastings unless one crosses the boundary between the two zones = (longitude =3D 12 ). You can even go further and assume that eastings = between 1,000,000 and 2,000,000 are in zone 1 and eastings between = 2,020,000 and 3,030,000 are in zone 2. Again, this should make sense = when looking at the map location of a given point.) PROJCS["Monte Mario (Rome) / Italy zone 1", GEOGCS["Monte Mario (Rome)", DATUM["Monte_Mario", SPHEROID["International 1924",6378388,297]], PRIMEM["Rome",12.4523333333333], UNIT["degree",0.0174532925199433]], PROJECTION["Transverse_Mercator"], PARAMETER["latitude_of_origin",0], PARAMETER["central_meridian",9], PARAMETER["scale_factor",0.9996], PARAMETER["false_easting",1500000], PARAMETER["false_northing",0], UNIT["metre",1]] EPSG=3D26592 PROJCS["Monte Mario (Rome) / Italy zone 2", GEOGCS["Monte Mario (Rome)", DATUM["Monte_Mario", SPHEROID["International 1924",6378388,297]], PRIMEM["Rome",12.4523333333333], UNIT["degree",0.0174532925199433]], PROJECTION["Transverse_Mercator"], PARAMETER["latitude_of_origin",0], PARAMETER["central_meridian",15], PARAMETER["scale_factor",0.9996], PARAMETER["false_easting",2520000], PARAMETER["false_northing",0], UNIT["metre",1]] EPSG=3D26632 ----- Original Message -----=20 From: Max Zhao=20 To: [email protected]=20 Sent: Thursday, July 03, 2003 9:00 AM Subject: Re: [OSRS] A question about Italy Map Projection. Jerry, Your information is exactly what I am looking for. I was thinking = about getting the Easting and Northing for Longitude =3D12 assuming it is in the east zone using FALSE = Easting =3D252000, and get another pair of Easting/Northing assuming it = is in the west zone using FALSE Easting =3D150000. Hopefully the first = Easting (EMidline_West) is much larger than the second Easting = (EMidline_East).=20 Now when I want to calculate Lat/Lon from a pair of (E, N) , I can = determine which set of parameters to use by comparing E to the = (EMidline_East+ EMidline_West)/2.=20 Does any one have more information about the overlapping thing for = Italy? Why should Italy have the overlapping region?? Thanks, = -------------------------------------------------------------------------= ----------------------------- Max Zhao RM2D15, Building104 Florham Park, NJ07932 Phone: (973) 236-6493 Fax: (973) 236-6679 = -------------------------------------------------------------------------= ----------------------------- ----- Original Message -----=20 From: Jerry Helfand=20 To: [email protected]=20 Sent: Wednesday, July 02, 2003 11:32 PM Subject: Re: [OSRS] A question about Italy Map Projection. I don't know the details of the zones for Italy, but I have a = comment Based on website, http://rmmcnt7.cr.usgs.gov/cscodes.htm=20 Italy zones are divided thus: "[Italy] IT-W =3D Italy, West Fuse, West of 12 degrees E IT-E =3D Italy, East Fuse, East of 12 degrees E " Thus, you have to know which part of Italy you're working. Unless = the False Easting at the central meridians differ enough, as Todd = Jamison said, x-y pairs would not be unique so some prior knowledge of = geographic location is necessary. Jerry Helfand=20 ----- Original Message -----=20 From: Max Zhao=20 To: [email protected]=20 Sent: Tuesday, July 01, 2003 3:37 PM Subject: [OSRS] A question about Italy Map Projection. I am working to convert a set of E&N coordinates in Italy back = into latitude and longitude. I know there are tow zones (east zone and = west zone) in Italy. The projection method is: Transverse Mercator or = Gauss Boaga. I also know the Roma 1840 Datum for the 2 zones.=20 My Question is: If I am given a pair of (E,N) coordinate, how = can I tell it is in the east zone or it is in the west zone?=20 I would greatly appreciate if any body can help me with this. Max zhao = -------------------------------------------------------------------------= ----------------------------- Max Zhao RM2D15, Building104 Florham Park, NJ07932 Phone: (973) 236-6493 Fax: (973) 236-6679 = -------------------------------------------------------------------------= ----------------------------- ------=_NextPart_000_02E1_01C34492.53415390 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=3DContent-Type content=3D"text/html; = charset=3Diso-8859-1"> <META content=3D"MSHTML 6.00.2800.1170" name=3DGENERATOR> <STYLE></STYLE> </HEAD> <BODY bgColor=3D#ffffff> <DIV> <DIV><FONT face=3DArial size=3D2>Jerry,</FONT></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2>Thanks a lot for your help. The = information you=20 provided is very convincing! Also I did a rough calculation</FONT></DIV> <DIV><FONT face=3DArial size=3D2>about range: major radius of earth =3D = <FONT=20 face=3D"Times New Roman" size=3D3>6378388 (m). So the circumstance of = the maximum=20 circle is: 2*pi*radius. And the maximal span for 3 degree is: = 2*pi*radius* 3/360=20 =3D 333971.61. Therefore starting from longitude of 9 and=20 going eastward, the maximal easting for 12 deg should not be larger = than=20 1833971.61m. If we go from 15 deg toward 12 deg in the east zone. The = easting=20 for 12 deg</FONT></FONT></DIV> <DIV>will be 2520000 - 333971.61 =3D 2186028.39. So the two zones = should=20 not intersect.</DIV> <DIV><FONT face=3DArial size=3D2></FONT><FONT face=3DArial = size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2>I tried my program on the set of (E,N) = data I have.=20 Then I found a problem. The eastings I got have some positive and=20 <STRONG>negative</STRONG> values. The boundary part looks like at = longitude of=20 12.50 deg. So I suspect that the</FONT></DIV> <DIV><FONT face=3DArial size=3D2>system uses only one set of datum = (one FALSE=20 Easting and Northing) at <FONT face=3D"Times New Roman"=20 size=3D3>Monte Mario (Rome). I revised my program to = set:</FONT></FONT></DIV> <DIV><FONT face=3DArial size=3D2><FONT face=3D"Times New Roman" = size=3D3>FALSE=20 northing=3D0,</FONT></FONT></DIV> <DIV><FONT face=3DArial size=3D2><FONT face=3D"Times New Roman" = size=3D3>FALSE easting=3D0=20 </FONT></FONT></DIV> <DIV><FONT face=3DArial size=3D2><FONT face=3D"Times New Roman" = size=3D3>latitude of=20 natural origin =3D 12.50 deg,</FONT></FONT></DIV> <DIV><FONT face=3DArial size=3D2><FONT face=3D"Times New Roman" = size=3D3>longitude of=20 natural origin =3D 0 deg.</FONT></FONT></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2>It is kind of weird that a grid system = have=20 negative values. So I guess I really need to get back to our data = source to=20 find out what is the conversion method they use.</FONT></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2>Thank you all for your = help.</FONT></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV> <DIV><FONT face=3DArial size=3D2> <DIV><FONT face=3DArial=20 size=3D2>----------------------------------------------------------------= --------------------------------------<BR>Max=20 Zhao<BR>RM2D15, Building104<BR>Florham Park, NJ07932<BR>Phone: (973)=20 236-6493<BR>Fax: (973)=20 236-6679<BR>-------------------------------------------------------------= -----------------------------------------</FONT></DIV></FONT></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV></DIV> <BLOCKQUOTE dir=3Dltr=20 style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV> <DIV=20 style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B>=20 <A [email protected] href=3D"mailto:[email protected]">Jerry = Helfand</A>=20 </DIV> <DIV style=3D"FONT: 10pt arial"><B>To:</B> <A = [email protected]=20 href=3D"mailto:[email protected]">[email protected]</A> = </DIV> <DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Friday, July 04, 2003 = 1:00 AM</DIV> <DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: [OSRS] A question = about=20 Italy Map Projection.</DIV> <DIV><FONT face=3DArial size=3D2></FONT><FONT face=3DArial = size=3D2></FONT><BR></DIV> <DIV><FONT size=3D2>Max,</FONT></DIV> <DIV><FONT size=3D2></FONT> </DIV> <DIV><FONT size=3D2>More info (kids are asleep and aimless web surfing = seems,=20 well, aimless...) :</FONT></DIV> <DIV><FONT size=3D2></FONT> </DIV> <DIV><FONT size=3D2>From website: <A=20 = href=3D"http://www.opengis.org/techno/interop/EPSG2WKT.TXT">http://www.op= engis.org/techno/interop/EPSG2WKT.TXT</A> =20 which I got from a HOTBOT search on "italy map system zone central = meridian":=20 </FONT></DIV> <DIV><FONT size=3D2></FONT> </DIV> <DIV><FONT size=3D2>(Todd Jamison is right. Zone 1 Eastings will = not=20 overlap Zone 2 Eastings unless one crosses the boundary between the = two zones=20 (longitude =3D 12 ). You can even go further and assume = that =20 eastings between 1,000,000 and 2,000,000 are in zone 1 and eastings = between=20 2,020,000 and 3,030,000 are in zone 2. Again, this should make = sense=20 when looking at the map location of a given point.)</FONT></DIV> <DIV><FONT size=3D2></FONT> </DIV> <DIV>PROJCS["Monte Mario (Rome) / Italy zone 1",</DIV> <DIV>GEOGCS["Monte Mario (Rome)",</DIV> <DIV>DATUM["Monte_Mario",</DIV> <DIV>SPHEROID["International 1924",6378388,297]],</DIV> <DIV>PRIMEM["Rome",12.4523333333333],</DIV> <DIV>UNIT["degree",0.0174532925199433]],</DIV> <DIV>PROJECTION["Transverse_Mercator"],</DIV> <DIV>PARAMETER["latitude_of_origin",0],</DIV> <DIV>PARAMETER["central_meridian",9],</DIV> <DIV>PARAMETER["scale_factor",0.9996],</DIV> <DIV>PARAMETER["false_easting",1500000],</DIV> <DIV>PARAMETER["false_northing",0],</DIV> <DIV>UNIT["metre",1]]<BR>EPSG=3D26592</DIV> <DIV><BR>PROJCS["Monte Mario (Rome) / Italy zone 2",</DIV> <DIV>GEOGCS["Monte Mario (Rome)",</DIV> <DIV>DATUM["Monte_Mario",</DIV> <DIV>SPHEROID["International 1924",6378388,297]],</DIV> <DIV>PRIMEM["Rome",12.4523333333333],</DIV> <DIV>UNIT["degree",0.0174532925199433]],</DIV> <DIV>PROJECTION["Transverse_Mercator"],</DIV> <DIV>PARAMETER["latitude_of_origin",0],</DIV> <DIV>PARAMETER["central_meridian",15],</DIV> <DIV>PARAMETER["scale_factor",0.9996],</DIV> <DIV>PARAMETER["false_easting",2520000],</DIV> <DIV>PARAMETER["false_northing",0],</DIV> <DIV>UNIT["metre",1]]<BR>EPSG=3D26632<BR></DIV> <BLOCKQUOTE dir=3Dltr=20 style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV> <DIV=20 style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B>=20 <A [email protected] = href=3D"mailto:[email protected]">Max Zhao</A>=20 </DIV> <DIV style=3D"FONT: 10pt arial"><B>To:</B> <A = [email protected]=20 href=3D"mailto:[email protected]">[email protected]</A> = </DIV> <DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Thursday, July 03, 2003 = 9:00=20 AM</DIV> <DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: [OSRS] A = question about=20 Italy Map Projection.</DIV> <DIV><BR></DIV> <DIV><FONT face=3DArial size=3D2>Jerry,</FONT></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2>Your information is exactly what I = am looking=20 for. I was thinking about getting the Easting and = Northing</FONT></DIV> <DIV><FONT face=3DArial size=3D2>for Longitude =3D12 assuming it is = in the east=20 zone using FALSE Easting =3D252000, and get another pair of = Easting/Northing=20 assuming it is in the west zone using FALSE Easting =3D150000. = Hopefully the=20 first Easting (EMidline_West) is much larger than the second Easting = (EMidline_East). </FONT></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2>Now when I want to calculate = Lat/Lon from a=20 pair of (E, N)</FONT> <FONT face=3DArial size=3D2>, I can = determine=20 which set of parameters to use by comparing E to the = (EMidline_East+=20 EMidline_West)/2. </FONT></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2>Does any one have more information = about the=20 overlapping thing for Italy? Why should Italy have the = overlapping=20 region??</FONT></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2>Thanks,</FONT></DIV> <DIV><FONT face=3DArial size=3D2> <DIV><FONT face=3DArial=20 = size=3D2>----------------------------------------------------------------= --------------------------------------<BR>Max=20 Zhao<BR>RM2D15, Building104<BR>Florham Park, NJ07932<BR>Phone: (973) = 236-6493<BR>Fax: (973)=20 = 236-6679<BR>-------------------------------------------------------------= -----------------------------------------</FONT></DIV></FONT></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <BLOCKQUOTE dir=3Dltr=20 style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV style=3D"FONT: 10pt arial">----- Original Message ----- = </DIV> <DIV=20 style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B>=20 <A [email protected] href=3D"mailto:[email protected]">Jerry = Helfand</A>=20 </DIV> <DIV style=3D"FONT: 10pt arial"><B>To:</B> <A = [email protected]=20 href=3D"mailto:[email protected]">[email protected]</A> = </DIV> <DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Wednesday, July 02, = 2003 11:32=20 PM</DIV> <DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: [OSRS] A = question about=20 Italy Map Projection.</DIV> <DIV><BR></DIV> <DIV><FONT size=3D2>I don't know the details of the zones for = Italy, but I=20 have a comment</FONT></DIV> <DIV><FONT size=3D2></FONT> </DIV> <DIV><FONT size=3D2>Based on website, <A=20 = href=3D"http://rmmcnt7.cr.usgs.gov/cscodes.htm">http://rmmcnt7.cr.usgs.go= v/cscodes.htm</A> </FONT></DIV> <DIV><FONT size=3D2></FONT> </DIV> <DIV><FONT size=3D2>Italy zones are divided thus:</FONT></DIV> <DIV><FONT size=3D2>"</FONT><FONT=20 size=3D3>[Italy]<BR>IT-W =3D Italy, West = Fuse, West of=20 12 degrees E<BR>IT-E =3D Italy, East Fuse, = East of=20 12 degrees E "<BR></FONT></DIV> <DIV><FONT size=3D3><FONT size=3D2>Thus, you have to know which = part of Italy=20 you're working. Unless the False Easting at the central = meridians=20 differ enough, as Todd Jamison said, x-y pairs would not be unique = so some=20 prior knowledge of geographic location is = necessary.</FONT></FONT></DIV> <DIV><FONT size=3D3><FONT size=3D2></FONT></FONT> </DIV> <DIV><FONT size=3D2>Jerry Helfand </FONT></DIV> <DIV><FONT size=3D2></FONT> </DIV> <DIV><FONT size=3D2></FONT> </DIV> <BLOCKQUOTE dir=3Dltr=20 style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; = BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px"> <DIV style=3D"FONT: 10pt arial">----- Original Message ----- = </DIV> <DIV=20 style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: = black"><B>From:</B>=20 <A [email protected] = href=3D"mailto:[email protected]">Max=20 Zhao</A> </DIV> <DIV style=3D"FONT: 10pt arial"><B>To:</B> <A = [email protected]=20 = href=3D"mailto:[email protected]">[email protected]</A> </DIV> <DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Tuesday, July 01, = 2003 3:37=20 PM</DIV> <DIV style=3D"FONT: 10pt arial"><B>Subject:</B> [OSRS] A = question about=20 Italy Map Projection.</DIV> <DIV><BR></DIV> <DIV><FONT face=3DArial size=3D2>I am working to convert a set = of E&N=20 coordinates in <STRONG>Italy</STRONG> back into latitude and = longitude.=20 I know there are tow zones (east zone and west zone) in Italy. = The=20 projection method is: Transverse Mercator or Gauss Boaga. I also = know=20 the Roma 1840 Datum for the 2 zones. </FONT></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2>My Question is: If I am given a = pair of=20 (E,N) coordinate, how can I tell it is in the east zone or it is = in the=20 west zone? </FONT></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2>I would greatly appreciate if = any body can=20 help me with this.</FONT></DIV> <DIV><FONT face=3DArial size=3D2></FONT> </DIV> <DIV><FONT face=3DArial size=3D2>Max zhao</FONT></DIV> <DIV><FONT face=3DArial size=3D2> <DIV><FONT face=3DArial=20 = size=3D2>----------------------------------------------------------------= --------------------------------------<BR>Max=20 Zhao<BR>RM2D15, Building104<BR>Florham Park, NJ07932<BR>Phone: = (973)=20 236-6493<BR>Fax: (973)=20 = 236-6679<BR>-------------------------------------------------------------= -----------------------------------------</FONT></DIV></FONT></DIV></BLOC= KQUOTE></BLOCKQUOTE></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML> ------=_NextPart_000_02E1_01C34492.53415390-- ---------------------------------------- Open Source Remote Sensing Project Discussion List To Subscribe: send a message to [email protected] with 'subscribe osrs' in the body To Unsubscribe: send a message to [email protected] with 'unsubscribe osrs' in the body To Report Problems: send a message to [email protected]