EPSG:9806

Cassini-Soldner

Attributes

Data source: OGP

Information source: EPSG guidance note #7-2, http://www.epsg.org

Revision date: 2017-06-13

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Definition: OGP XML

<?xml version="1.0" encoding="UTF-8"?>
 <gml:OperationMethod xmlns:epsg="urn:x-ogp:spec:schema-xsd:EPSG:1.0:dataset" xmlns:gml="http://www.opengis.net/gml/3.2" xmlns:xlink="http://www.w3.org/1999/xlink" gml:id="iogp-method-9806">
  <gml:metaDataProperty>
    <epsg:CommonMetaData>
      <epsg:informationSource>EPSG guidance note #7-2, http://www.epsg.org</epsg:informationSource>
      <epsg:revisionDate>2017-06-13</epsg:revisionDate>
      <epsg:changes>
        <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2017.018" />
      </epsg:changes>
      <epsg:show>true</epsg:show>
      <epsg:isDeprecated>false</epsg:isDeprecated>
    </epsg:CommonMetaData>
  </gml:metaDataProperty>
  <gml:metaDataProperty>
    <epsg:CoordinateOperationMethodMetaData>
      <epsg:isOperationReversible>true</epsg:isOperationReversible>
      <epsg:signReversal changeSign="false" xlink:href="urn:ogc:def:parameter:EPSG::8801" />
      <epsg:signReversal changeSign="false" xlink:href="urn:ogc:def:parameter:EPSG::8802" />
      <epsg:signReversal changeSign="false" xlink:href="urn:ogc:def:parameter:EPSG::8806" />
      <epsg:signReversal changeSign="false" xlink:href="urn:ogc:def:parameter:EPSG::8807" />
      <epsg:example>For Projected Coordinate System Trinidad 1903 / Trinidad Grid 
Parameters:
Ellipsoid   Clarke 1858     a = 20926348 ft    = 31706587.88 links
                                        b = 20855233 ft

then 1/f = 294.97870 and e^2 = 0.00676866

Latitude Natural Origin       10°26'30"N  =  0.182241463 rad
Longitude Natural Origin    61°20'00"W = -1.07046861 rad
False Eastings FE              430000.00 links
False Northings FN            325000.00 links

Forward calculation for: 
Latitude       10°00'00.00" N = 0.17453293 rad
Longitude    62°00'00.00"W = -1.08210414 rad

A = -0.01145876      C = 0.00662550
T = 0.03109120      M = 5496860.24    nu = 31709831.92     M0 = 5739691.12

Then Easting E    =  66644.94 links
          Northing N =  82536.22 links

Reverse calculation for same easting and northing first gives :
e1    =   0.00170207       D  =     -0.01145875
T1   = 0.03109544         M1 =      5497227.34
nu1  = 31709832.34       mu1 =    0.17367306
phi1 = 0.17454458         rho1 =    31501122.40


Then Latitude     = 10°00'00.000"N
         Longitude  =  62°00'00.000"W</epsg:example>
    </epsg:CoordinateOperationMethodMetaData>
  </gml:metaDataProperty>
  <gml:identifier codeSpace="IOGP">urn:ogc:def:method:EPSG::9806</gml:identifier>
  <gml:name>Cassini-Soldner</gml:name>
  <gml:formula>Note: These formulas have been transcribed from EPSG Guidance Note #7-2. Users are encouraged to use that document rather than the text which follows as reference because limitations in the transcription will be avoided.

The formulas to derive projected Easting and Northing coordinates are:

Easting E = FE + nu[A - TA^3/6 -(8 - T + 8C)TA^5/120]

Northing N = FN + M - M0 + nu*tan(lat)*[A^2/2 + (5 - T + 6C)A^4/24]

where A = (lon - lon0)cos(lat)
T = tan^2(lat)
C = e2 cos2*/(1 - e2)        nu = a /(1 - esq*sin^2(lat))^0.5 
and M, the distance along the meridian from equator to latitude lat, is given by
M = a[(1 - e^2/4 - 3e^4/64 - 5e^6/256 -....)*lat - (3e^2/8 + 3e^4/32 + 45e^6/1024 +....)sin(2*lat) + (15e^4/256 + 45e^6/1024 +.....)sin(4*lat) - (35e^6/3072 + ....)sin(6*lat) + .....]
with lat in radians.

M0 is the value of M calculated for the latitude of the chosen origin. This may not necessarily be chosen as the equator.

To compute latitude and longitude from Easting and Northing the reverse formulas are:
lat = lat1 - (nu1tan(lat1)/rho1)[D2/2 - (1 + 3*T1)D^4/24]
lon =  lon0 + [D - T1*D^3/3 + (1 + 3*T1)T1*D^5/15]/cos(lat1)

where lat1 is the latitude of the point on the central meridian which has the same Northing as the point whose coordinates are sought, and is found from:
lat1 = mu1 + (3*e1/2 - 27*e1^3/32 +.....)sin(2*mu1) + (21*e1^2/16 - 55*e1^4/32 + ....)sin(4*mu1)+ (151*e1^3/96 +.....)sin(6*mu1) + (1097*e1^4/512 - ....)sin(8*mu1) + ......
where
e1 = [1- (1 - esq)^0.5]/[1 + (1 - esq)^0.5]
mu1 = M1/[a(1 - esq/4 - 3e^4/64 - 5e^6/256 - ....)]
M1 = M0 + (N - FN)
T1 = tan^2(lat1)
D = (E - FE)/nu1</gml:formula>
  <gml:generalOperationParameter xlink:href="urn:ogc:def:parameter:EPSG::8801" />
  <gml:generalOperationParameter xlink:href="urn:ogc:def:parameter:EPSG::8802" />
  <gml:generalOperationParameter xlink:href="urn:ogc:def:parameter:EPSG::8806" />
  <gml:generalOperationParameter xlink:href="urn:ogc:def:parameter:EPSG::8807" />
</gml:OperationMethod>
<?xml version="1.0" encoding="UTF-8"?>
 <gml:OperationMethod xmlns:epsg="urn:x-ogp:spec:schema-xsd:EPSG:1.0:dataset" xmlns:gml="http://www.opengis.net/gml/3.2" xmlns:xlink="http://www.w3.org/1999/xlink" gml:id="iogp-method-9806">
  <gml:metaDataProperty>
    <epsg:CommonMetaData>
      <epsg:informationSource>EPSG guidance note #7-2, http://www.epsg.org</epsg:informationSource>
      <epsg:revisionDate>2017-06-13</epsg:revisionDate>
      <epsg:changes>
        <epsg:changeID xlink:href="urn:ogc:def:change-request:EPSG::2017.018" />
      </epsg:changes>
      <epsg:show>true</epsg:show>
      <epsg:isDeprecated>false</epsg:isDeprecated>
    </epsg:CommonMetaData>
  </gml:metaDataProperty>
  <gml:metaDataProperty>
    <epsg:CoordinateOperationMethodMetaData>
      <epsg:isOperationReversible>true</epsg:isOperationReversible>
      <epsg:signReversal changeSign="false" xlink:href="urn:ogc:def:parameter:EPSG::8801" />
      <epsg:signReversal changeSign="false" xlink:href="urn:ogc:def:parameter:EPSG::8802" />
      <epsg:signReversal changeSign="false" xlink:href="urn:ogc:def:parameter:EPSG::8806" />
      <epsg:signReversal changeSign="false" xlink:href="urn:ogc:def:parameter:EPSG::8807" />
      <epsg:example>For Projected Coordinate System Trinidad 1903 / Trinidad Grid 
Parameters:
Ellipsoid   Clarke 1858     a = 20926348 ft    = 31706587.88 links
                                        b = 20855233 ft

then 1/f = 294.97870 and e^2 = 0.00676866

Latitude Natural Origin       10°26'30"N  =  0.182241463 rad
Longitude Natural Origin    61°20'00"W = -1.07046861 rad
False Eastings FE              430000.00 links
False Northings FN            325000.00 links

Forward calculation for: 
Latitude       10°00'00.00" N = 0.17453293 rad
Longitude    62°00'00.00"W = -1.08210414 rad

A = -0.01145876      C = 0.00662550
T = 0.03109120      M = 5496860.24    nu = 31709831.92     M0 = 5739691.12

Then Easting E    =  66644.94 links
          Northing N =  82536.22 links

Reverse calculation for same easting and northing first gives :
e1    =   0.00170207       D  =     -0.01145875
T1   = 0.03109544         M1 =      5497227.34
nu1  = 31709832.34       mu1 =    0.17367306
phi1 = 0.17454458         rho1 =    31501122.40


Then Latitude     = 10°00'00.000"N
         Longitude  =  62°00'00.000"W</epsg:example>
    </epsg:CoordinateOperationMethodMetaData>
  </gml:metaDataProperty>
  <gml:identifier codeSpace="IOGP">urn:ogc:def:method:EPSG::9806</gml:identifier>
  <gml:name>Cassini-Soldner</gml:name>
  <gml:formula>Note: These formulas have been transcribed from EPSG Guidance Note #7-2. Users are encouraged to use that document rather than the text which follows as reference because limitations in the transcription will be avoided.

The formulas to derive projected Easting and Northing coordinates are:

Easting E = FE + nu[A - TA^3/6 -(8 - T + 8C)TA^5/120]

Northing N = FN + M - M0 + nu*tan(lat)*[A^2/2 + (5 - T + 6C)A^4/24]

where A = (lon - lon0)cos(lat)
T = tan^2(lat)
C = e2 cos2*/(1 - e2)        nu = a /(1 - esq*sin^2(lat))^0.5 
and M, the distance along the meridian from equator to latitude lat, is given by
M = a[(1 - e^2/4 - 3e^4/64 - 5e^6/256 -....)*lat - (3e^2/8 + 3e^4/32 + 45e^6/1024 +....)sin(2*lat) + (15e^4/256 + 45e^6/1024 +.....)sin(4*lat) - (35e^6/3072 + ....)sin(6*lat) + .....]
with lat in radians.

M0 is the value of M calculated for the latitude of the chosen origin. This may not necessarily be chosen as the equator.

To compute latitude and longitude from Easting and Northing the reverse formulas are:
lat = lat1 - (nu1tan(lat1)/rho1)[D2/2 - (1 + 3*T1)D^4/24]
lon =  lon0 + [D - T1*D^3/3 + (1 + 3*T1)T1*D^5/15]/cos(lat1)

where lat1 is the latitude of the point on the central meridian which has the same Northing as the point whose coordinates are sought, and is found from:
lat1 = mu1 + (3*e1/2 - 27*e1^3/32 +.....)sin(2*mu1) + (21*e1^2/16 - 55*e1^4/32 + ....)sin(4*mu1)+ (151*e1^3/96 +.....)sin(6*mu1) + (1097*e1^4/512 - ....)sin(8*mu1) + ......
where
e1 = [1- (1 - esq)^0.5]/[1 + (1 - esq)^0.5]
mu1 = M1/[a(1 - esq/4 - 3e^4/64 - 5e^6/256 - ....)]
M1 = M0 + (N - FN)
T1 = tan^2(lat1)
D = (E - FE)/nu1</gml:formula>
  <gml:generalOperationParameter xlink:href="urn:ogc:def:parameter:EPSG::8801" />
  <gml:generalOperationParameter xlink:href="urn:ogc:def:parameter:EPSG::8802" />
  <gml:generalOperationParameter xlink:href="urn:ogc:def:parameter:EPSG::8806" />
  <gml:generalOperationParameter xlink:href="urn:ogc:def:parameter:EPSG::8807" />
</gml:OperationMethod>