Here is an example:
[Destination]
DestDir = "D:\temp\FSET\FSX\Addon Scenery\FSEarthTiles\LacLola FSX\scenery"
DestBaseFileName = Area_Lp1_SnapOff_N045444092_N045435607_W076111395_W076095856_seasons_Blendstest2
BuildSeasons = 0
UseSourceDimensions = 1
CompressionQuality = 100
[Source]
Type = MultiSource
NumberOfSources = 6
[Source1]
Type = BMP
Layer = Imagery
SourceDir = D:\FSZIP\utilities\FSEarthTiles\work\LacLola
SourceFile = Area_Lp1_SnapOff_N045444092_N045435607_W076111395_W076095856HIWIW.bmp
Lon = -76.1872100830078 ;for top left and bottom right is: -76.1662530899048
Lat = 45.7447099685669 ;for top left and bottom right is: 45.7322323322296
NumOfCellsPerLine = 1465 ;Pixel is not used in FSX
NumOfLines = 1163 ;Pixel is not used in FSX
CellXdimensionDeg = 1.43051147460938E-05
CellYdimensionDeg = 1.07288360595703E-05
PixelIsPoint = 0
SamplingMethod = Gaussian
Variation = January,February,March,November,December
Channel_Blendmask = 6.0
[Source2]
Type = BMP
Layer = Imagery
SourceDir = D:\FSZIP\utilities\FSEarthTiles\work\LacLola
SourceFile = Area_Lp1_SnapOff_N045444092_N045435607_W076111395_W076095856coladj.bmp
Lon = -76.1872100830078 ;for top left and bottom right is: -76.1662530899048
Lat = 45.7447099685669 ;for top left and bottom right is: 45.7322323322296
NumOfCellsPerLine = 1465 ;Pixel is not used in FSX
NumOfLines = 1163 ;Pixel is not used in FSX
CellXdimensionDeg = 1.43051147460938E-05
CellYdimensionDeg = 1.07288360595703E-05
PixelIsPoint = 0
SamplingMethod = Gaussian
Variation = April,May,June,July,August,September,October
Channel_Blendmask = 4.0
Channel_LandWaterMask = 5.0
[Source3]
Type = BMP
Layer = Imagery
SourceDir = D:\FSZIP\utilities\FSEarthTiles\work\LacLola
SourceFile = Area_Lp1_SnapOff_N045444092_N045435607_W076111395_W076095856coladjnight.bmp
Lon = -76.1872100830078 ;for top left and bottom right is: -76.1662530899048
Lat = 45.7447099685669 ;for top left and bottom right is: 45.7322323322296
NumOfCellsPerLine = 1465 ;Pixel is not used in FSX
NumOfLines = 1163 ;Pixel is not used in FSX
CellXdimensionDeg = 1.43051147460938E-05
CellYdimensionDeg = 1.07288360595703E-05
PixelIsPoint = 0
SamplingMethod = Gaussian
Variation = Night
Channel_Blendmask = 4.0
Channel_LandWaterMask = 5.0
[Source4]
Type = TIFF
Layer = None
SourceDir = D:\FSZIP\utilities\FSEarthTiles\work\LacLola
SourceFile = Area_Lp1_SnapOff_N045444092_N045435607_W076111395_W076095856blendtest.tif
Lon = -76.1872100830078 ;for top left and bottom right is: -76.1662530899048
Lat = 45.7447099685669 ;for top left and bottom right is: 45.7322323322296
NumOfCellsPerLine = 1465 ;Pixel is not used in FSX
NumOfLines = 1163 ;Pixel is not used in FSX
CellXdimensionDeg = 1.43051147460938E-05
CellYdimensionDeg = 1.07288360595703E-05
PixelIsPoint = 0
SamplingMethod = Gaussian
Variation = April,May,June,July,August,September,October
[Source5]
Type = TIFF
Layer = None
SourceDir = D:\FSZIP\utilities\FSEarthTiles\work\LacLola
SourceFile = Area_Lp1_SnapOff_N045444092_N045435607_W076111395_W076095856water2.tif
Lon = -76.1872100830078 ;for top left and bottom right is: -76.1662530899048
Lat = 45.7447099685669 ;for top left and bottom right is: 45.7322323322296
NumOfCellsPerLine = 1465 ;Pixel is not used in FSX
NumOfLines = 1163 ;Pixel is not used in FSX
CellXdimensionDeg = 1.43051147460938E-05
CellYdimensionDeg = 1.07288360595703E-05
PixelIsPoint = 0
SamplingMethod = Gaussian
[Source6]
Type = TIFF
Layer = None
SourceDir = D:\FSZIP\utilities\FSEarthTiles\work\LacLola
SourceFile = Area_Lp1_SnapOff_N045444092_N045435607_W076111395_W076095856blend2.tif
Lon = -76.1872100830078 ;for top left and bottom right is: -76.1662530899048
Lat = 45.7447099685669 ;for top left and bottom right is: 45.7322323322296
NumOfCellsPerLine = 1465 ;Pixel is not used in FSX
NumOfLines = 1163 ;Pixel is not used in FSX
CellXdimensionDeg = 1.43051147460938E-05
CellYdimensionDeg = 1.07288360595703E-05
PixelIsPoint = 0
SamplingMethod = Gaussian
Variation = January,February,March,November,December