User`s guide

Table B-4d. SDF_DATA_HDR (Data Header record)
Field
Index
Binary
Index*
Field Name/Description
Data
Type
Range/
Units
19 59:60 yIsValid — (0=not valid, 1=valid) short 0:1
20 61:64
first_VECTOR_recordNum — first Vector Header record
belonging to this Data Header record
long 0:(num_of_
VECTOR_
record) − 1
(SDF_FILE_
HDR)
21 65:66 total_rows — used to determine the number of traces
associated with this Data header record; just multiply
total_rows by total_columns
short 1:32767
22 67:68 total_cols — used to determine the number of traces
associated with this Data header record; just multiply
total_rows by total_columns
short 1:32767
23 69:90 xUnit — engineering unit used for x-axis values. struct see SDF_UNIT
24 91:92 yUnitValid — yUnit field in this record is valid
0=use Channel Header record’s engUnit field for
y-axis units.
1=use this record’s yUnit field for y-axis unit.
short 0:1
25 93:114 yUnit — engineering unit used for y-axis values. struct see SDF_UNIT
26 115:122 abscissa_firstX — x-axis value of first point. This field is only
valid if xResolution_type is 0 or 1.
double
10
34
27 123:130 abscissa_deltaX — spacing between x-axis points.
xn = x(n-1) + abscissa_deltaX (xResolution_type 0)
xn=x(n−1)abscissa_deltaX (xResolution_type 1)
This field is only valid if xResolution_type is 0 or 1.
double
10
34
28 131:132 scanData — indicates whether the data is scanned
0 = This data header is associated with non-scanned data
1= This data header is associated with the scan structure
short 0:1
29 133:134 windowApplied — indicates whether the windows indicated
have already been applied to the data
0 = windows have not been applied
1 = windows have been applied
short 0:1
30 135:138 num_of_points — number of discrete points in each trace
associated with this record.
long
0:(2
31
)−1
31 139:142
last_valid_index — last point containing valid data. long 0:(num_of_points
)−1
32 143:144 overSampleFactor — Usually 1
> 1 = the data has been low-pass filtered but
not decimated.
short 1:32767
33 145:146 multiPassMode — ‘’Multi-pass’’ refers to a mode where data for
multiple frequency spans is interleaved.
0 = not multi-pass data
1..4 = multi-pass, corresponding the HP 3565
gate array modes
5 = future multi-pass mode
short
0:5
Standard Data Format (SDF)
B-16