This example is given in the UKOOA P6/98 document. Source coordinate reference system: imaginary 3D seismic acquisition bin grid. The two axes are orthogonal, but the bin width on the I-axis (XS axis) is 25 metres, whilst the bin width on the J-axis (YS axis) is 12.5 metres. The origin of the grid has bin values of 1,1.¶¶The target coordinate reference system is a projected CRS (WGS 84 / UTM Zone 31N) upon which the origin of the bin grid is defined at E = 456781.0, N = 5836723.0.  The projected coordinate reference system point scale factor at the bin grid origin is 0.99984.¶¶In the map grid (target CRS), the bearing of the bin grid (source CRS) I and J axes are 110deg and 20deg respectively.  Thus the angle through which the bin grid axes need to be rotated to coincide with the map grid axes is +20 degrees.¶¶The transformation parameter values are:¶¶Parameter                                     	Parameter value¶Bin grid origin                                 	1¶Bin grid origin                                 	1¶Bin grid origin Easting                       	456781.00 m¶Bin grid origin Northing                    5836723.00 m¶Scale factor of bin grid  	                	0.99984¶Bin Width on I-axis                         	25 m¶Bin Width on J-axis                        	12.5 m¶Map grid bearing of bin grid J-axis    	20 deg¶Bin node increment on I-axis           	1¶Bin node increment on J-axis          	1¶¶
Forward calculation for centre of bin with coordinates: I = 300, J = 247:¶XT = Easting   = XTO   +   [(XS – XSO) * cos q * k * MX / IncSX]  +  [(YS – YSO) * sin q * k * MY / IncSY]¶= 456781.000 + 7023.078 + 1051.544 ¶= 464855.62 m.¶¶YT = Northing = YTO   –   [(XS – XSO) * sin q * k * MX / IncSX]   +  [(YS – YSO) * cos q * k * MY / IncSY]¶= 5836723.000 - 2556.192 + 2889.092¶= 5837055.90 m.¶¶Reverse calculation for this point 464 855.62mE, 5 837 055.90mN:¶XS = {[( XT  – XTO) * cos q  –  (YT – YTO) * sin q ] * [IncSX  / (k * MX)]} + XSO ¶= 300 bins, ¶¶YS = {[(XT   – XTO) * sin q   +  (YT – YTO) * cos q] * [IncSY  / (k * MY)]} + YSO ¶= 247 bins