Trace Header Variables for Math Expressions

DUG Insight uses SEG-Y rev 1 headers in its internal data format. This table lists the purpose to which Insight puts those headers, assuming that the data was loaded from field tapes in Insight, and that the header values haven't since been modified. If Insight doesn't use a header for any particular purpose, its SEG-Y rev 1 description is given.

Your data, of course, might have values in these headers that have different meanings.

Trace Headers

Bytes Variable Name Scalar Description
Trace Sequence Line

DUG Channel Number
9-12 FLDR

Field File Number
13-16 TRACF

Unique Field Channel Number
17-20 EP
DUG Shotpoint Number
21-24 CDP
25-28 CDPT
DUG Receiver Station
29-30 TRID
Trace Identification Code
31-32 NVS
N Summed Traces
33-34 NHS
35-36 DUSE
Data Use
37-40 OFFSET
41-44 GELEV SCALEL Receiver Depth
45-48 SELEV SCALEL Source Depth
49-52 SDEPTH SCALEL Receiver Water Depth
53-56 GDEL SCALEL Receiver Datum Elevation
57-60 SDEL SCALEL Source Datum Elevation
61-64 SWDEP SCALEL Source Water Depth
65-68 GWDEP SCALEL Water Depth at IL/CL
69-70 SCALEL
Elevation Scalar
71-72 SCALCO
Coordinate Scalar
73-76 SX SCALCO Source X
77-80 SY SCALCO Source Y
81-84 GX SCALCO Group X
85-88 GY SCALCO Group Y
89-90 COUNIT
Coordinate Unites
91-92 WEVEL
Water Velocity
93-94 SWEVEL
Sub Weathering Velocity
95-96 SUT
Marine: Tidal Corr in cm; Land: Src Uphole Time
97-98 GUT
Marine: Tidal Corr in µs; Land: Grp Uphole Time
99-100 SSTAT
Source Static Correction
101-102 GSTAT

Group Static Correction
103-104 TSTAT

Total Static Applied
105-106 LAGA

SEG-D Skew
107-108 LAGB

SEG-D Timing Word
109-110 DELRT

Delay Recording Time
111-112 MUTS

Start Muted Sample Count
113-114 MUTE

End Muted Sample Count
115-116 NS

Number of Samples
117-118 DT

Sample Rate
119-120 GAIN

Gain Type
121-122 IGC
Instrument Gain Constant
123-124 IGI
Instrument Initial Gain
125-126 CORR
127-128 SFS
Vessel Speed (cm/s)
129-130 SFE
Vessel Direction (degrees)
131-132 SLEN

SEG-D Channel Set
133-134 STYP

Sweep Type
135-136 STAS

Sweep Trace Taper Length Start
137-138 STAE

Gun Volume Fired
139-140 TATYP

Angle * 100
141-142 AFILF

Alias Filter Frequency
143-144 AFILS

Alias Filter Slope
145-146 NOFILF

Notch Filter Frequency
147-148 NOFILS

Notch Filter Slope
149-150 LCF

Low Cut Frequency
151-152 HCF

High Cut Frequency
153-154 LCS

Low Cut Slope
155-156 HCS

157-158 YEAR

Year Data Recorded
159-160 DAY

Day of Year
161-162 HOUR

Hour of Day
163-164 MINUTE

Minute of Hour
165-166 SEC

Second of Minute
167-168 TIMBAS

SEG-D trace edit code
169-170 TRWF

Trace Weighting Factor
171-172 GRNORS

173-174 GRNOFR

175-176 GRNLOF

Geophone Group Number Last Trace Orig Field
177-178 GAPS

DUG Receiver Station Index
179-180 OTRAV

181-184 CDPX
Ensemble X
185-188 CDPY
Ensemble Y
189-192 INLINE

3D Inline

3D Crossline

Field Shotpoint Number
201-202 SCALSP

Shotpoint scalar
203-204 TVMU

Trace Value Measurement Unit
205-208 TCM

Continuous Recording Delta-T (µs)
209-210 TCP

Transduction Constant Power 
211-212 TU

Transduction Unit
213-214 TID

SEG-D Gun Mask
215-216 STH

Scalar Trace Header
217-218 ST

Source Type
219-222 SEDM

Recording Time µs
223-224 SEDE

Sequence Inline Number
225-228 SMM

Continuous Recording Delta-T (Shots 2-3)
229-230 SME

Raw SEG-D File Index
231-232 SMU

Raw SEG-D Channel Index
233-236 UI1

Section Serial Number
237-240 UI2

Sequence Number / Continuous Recording Delta-T (Shots 2-4)