SDF Format (Surface Data File)
 
ASCII Data Type Explanation Data Type (if binary)
Bytes

Version Number (a: ASCII, b: binary) Unsigned Char
8
ManufacID Manufacturer ID Unsigned Char
10
Create Date Create Date and Time Unsigned Char
12
ModDate Modified Date and Time Unsigned Char
12
NumPoints Number of points in a profile Unsigned Int
2
NumProfiles Number of profiles in a data file Unsigned Int
2
Xscale X-scale. A x-scale value of 1.00 E-6 represents a sample spacing of 1 micrometer Double
8
Yscale Y-scale. A y-scale value of 1.00 E-6 represents a sample spacing of 1 micrometer Double
8
Zscale Z-scale. A z-scale value of 1.00 E-6 represents a height of 1 micrometer Double
8
Zresolution Z- resolution Double
8
Compression Compression Type Unsigned Char
1
Data types Data Type (0: unsigned char, 1: unsigned integer, 2: unsigned long, 3: float, 4: signed char, 5: signed integer, 6 signed long, 7: double) Unsigned Char
1
CheckType Check Sum Type Unsigned Char
1

Z-data values are delimited by asterisks (*). Each height equals the z-values multiplied by the Z-scale value above.

Data Type supported in Data Area

Data Type Code
Data Type
Bytes
0
Unsigned Char
1
1
Unsigned Int
2
2
Unsigned Long
4
3
Float
4
4
Signed Char
1
5
Signed Int
2
6
Signed Long
4
7
Double
8


Example
aBC-1.0
ManufacID            = Sine
CreateDate            = 031019971457
ModDate               = 031019971457
NumPoints             = 8000
NumProfiles           =  1
Xscale                   = 0.5e-6
Yscale                   = 0
Zscale                   = 1.0e-10
Zresolution            = 0
Compression         = 0
DataType             = 5
CheckType          = 0
*

0
79
157
236
314
393
471
...
...
...
...
-323
-244
-166
-87
0
*

Reference

K. J. Stout, P. J. Sullivan, W. P. Dong, E. Mainsah, N. Lou, T. Mathia and H. Zahouani, The Development of Methods for The Characterisation of Roughness in Three Dimensions, Report EUR 15178 EN. EC Brussels, 1993