| C 1 CLIENT COMPANY CREW NO |
| C 2 LINE line1dS AREA MAP ID |
| C 3 REEL NO DAY-START OF REEL YEAR OBSERVER |
| C 4 INSTRUMENT: DELPH MODEL xx SERIAL NO |
| C 5 DATA TRACES/RECORD 1 AUXILIARY TRACES/RECORD 0 CDP FOLD |
| C 6 SAMPLE INTERVAL 333 SAMPLES/TRACE 1496 BITS/IN 16 BYTES/SAMPLE
2 |
| C 7 RECORDING FORMAT FORMAT THIS REEL MEASUREMENT SYSTEM |
| C 8 SAMPLE CODE: FIXED PT |
| C 9 GAIN TYPE: FIXED |
| C10 FILTERS: ALIAS 1500HZ NOTCH HZ BAND - HZ SLOPE - DB/OCT |
| C11 SOURCE: TYPE NUMBER/POINT POINT INTERVAL |
| C12 PATTERN: LENGTH WIDTH |
| C13 SWEEP: START HZ END HZ LENGTH MS CHANNEL NO TYPE |
| C14 TAPER: START LENGTH MS END LENGTH MS TYPE |
| C15 SPREAD: OFFSET MAX DISTANCE GROUP INTERVAL |
| C16 GEOPHONES: PER GROUP SPACING FREQUENCY MFG MODEL |
| C17 PATTERN: LENGTH WIDTH |
| C18 TRACES SORTED BY: RECORD |
| C19 AMPLITUDE RECOVERY: NONE |
| C20 MAP PROJECTION ZONE ID COORDINATE UNITS |
| C21 PROCESSING: |
| C22 PROCESSING: |
| C23 |
| C24 |
| C25 |
| C26 |
| C27 |
| C28 |
| C29 |
| C30 |
| C31 |
| C32 |
| C33 |
| C34 |
| C35 |
| C36 |
| C37 |
| C38 |
| C39 |
| C40 END EBCDIC |
| Byte Numbers |
Header Value Description |
| 3201 - 3204 |
Job identification number. |
| 3205 - 3208 |
Line number. |
| 3209 - 3212 |
Reel number. |
| 3213 - 3214 |
Number of data traces
per record. |
| 3215 - 3216 |
Number of auxiliary traces per record. |
| 3217 - 3218 |
Sample interval, microseconds,
this file (reel). |
| 3219 - 3220 |
Sample interval, microseconds,
original field recording. |
| 3221 - 3222 |
Number of samples per
data trace, this file (reel). |
| 3223 - 3224 |
Number of samples per
data trace, original field recording. |
| 3225 - 3226 |
Data sample format code:
1 = floating point (4 bytes) 2 = fixed point (4 bytes) 3 = fixed point (2
bytes) 4 = fixed point with gain code (4 bytes). |
| 3227 - 3228 |
CDP fold. |
| 3229 - 3230 |
Trace sorting code: 1 = as recorded (no) sorting)
2 = CDP ensemble 3 = single fold continuous profile 4 = horizontally stacked |
| 3231 - 3232 |
Vertical sum code: 1 = no sum 2 = two sum ...
N = N sum (N = 32,767) |
| 3233 - 3234 |
Sweep frequency at start. |
| 3235 - 3236 |
Sweep frequency at end. |
| 3237 - 3238 |
Sweep length, ms. |
| 3239 - 3240 |
Sweep type code: 1 =
linear 2 = parabolic 3 = exponential 4 = other |
| 3241 - 3242 |
Trace number of sweep channel. |
| 3243 - 3244 |
Sweep trace taper length, ms, at start if tapered. |
| 3245 - 3246 |
Sweep trace taper length, ms, at end. |
| 3247 - 3248 |
Taper type: 1 = linear 2 = cos 3 = other |
| 3249 - 3250 |
Correlated data traces: 1 = no 2 = yes |
| 3251 - 3252 |
Binary gain recovered: 1 = yes 2 = no |
| 3253 - 3254 |
Amplitude recovery method: 1 = none 2 = spherical
divergence 3 = AGC 4 = other |
| 3255 - 3256 |
Measurement system: 1 = meters 2 = feet |
| 3257 - 3258 |
Impulse signal: 1 = Upward = negative number.
2 = Upward = positive number. |
| 3259 - 3260 |
Vibratory polarity code - seismic signal lags
pilot signal by: 1 = 337.5 - 22.5 degrees 2 = 22.5 - 67.5 degrees 3 = 67.5
- 112.5 degrees 4 = 112.5 - 157.5 degrees 5 = 157.5 - 202.5 degrees 6 =
202.5 - 247.5 degrees |
|
Byte Numbers
|
Header Value Description
|
|
1 - 4
|
Trace sequence number within
line.
|
|
5 - 8
|
Trace sequence
number within file (reel)
|
|
9 - 12
|
Original
field record number
|
|
13 - 16
|
Trace
number within original field record
|
|
17 - 20
|
Energy source point number.
|
|
21 - 24
|
CDP ensemble number.
|
|
25 - 2
|
Trace number within the CDP
ensemble.
|
|
29 - 30
|
Trace
identification code: 1 = seismic data
|
|
31 - 32
|
Number of vertically summed
traces yielding this trace
|
|
33 - 34
|
Number of horizontally stacked
traces yielding this trace
|
|
35 - 36
|
Data use: 1 = production 2
= test
|
|
37 - 40
|
Distance from source point
to receiver group.
|
|
41 - 44
|
Receiver group elevation -
above sea level are positive, below sea level are negative.
|
|
45 - 48
|
Surface elevation at source.
|
|
49 - 52
|
Source depth below surface
(positive number).
|
|
53 - 56
|
Datum elevation at receiver
group.
|
|
57 - 60
|
Datum elevation at source.
|
|
61 - 64
|
Water depth
at source (this is the Fish depth below the sea surface in meters*10)
|
|
65 - 68
|
Water depth at group.
|
|
69 - 70
|
Scalar to be applied to all
elevations & depths, specified in bytes 41 - 68 to give the real value.
Scalar = 1, +/-10, +/-100, +/-1000, or +/-10,000. If positive, scalar
is used as a multiplier; if negative, scalar is used as a divisor.
|
|
71 - 72
|
Scalar to be applied to all
coordinate specified in bytes 73 - 88 to give the real value. Scalar =
1, +/-10, +/-100, +/-1000, or +/-10,000. If positive, scalar is
used as a multiplier; if negative, scalar is used as a divisor.
|
|
73 - 76
|
Source
coordinate - X. UTM Easting coordinate
|
|
77 - 80
|
Source
coordinate - Y. UTM Northing coordinate
|
|
81 - 84
|
Group
coordinate - X. UTM Easting coordinate
|
|
85 - 88
|
Group
coordinate - Y. UTM Northing coordinate
|
|
89 - 90
|
Coordinate units: 1 = length
(meters or feet) 2 = seconds of arc
|
|
91 - 92
|
weathering velocity.
|
|
93 - 94
|
Subweathering velocity.
|
|
95 - 96
|
Uphole time at source.
|
|
97 - 98
|
Uphole time at group.
|
|
99 - 100
|
Source static correction.
|
|
101 - 102
|
Group static correction.
|
|
103 - 104
|
Total static applied.
|
|
105 - 106
|
Lag time A. Time in ms between
end of 240-byte trace identification header and time break. Positive
if time break occurs after end of header, negative if time break occurs
before end of header. Time break is defined as the initiation pulse which
may be recorded on an auxiliary trace or as otherwise specified by the
recording system.
|
|
107 - 108
|
Lag time B. Time in ms between
the time break and positive or negative.
|
|
109 - 110
|
Delay recording
time. Time in ms between initiation time of energy source and time
when recording of data samples begins.
|
|
111 - 112
|
Mute time - start.
|
|
113 - 114
|
Mute time - end.
|
|
115 -
116
|
Number
of samples in this trace.
|
|
117 -
118
|
Sample
interval, in microseconds, for this trace.
|
|
119 - 120
|
Gain type of field instruments:
1 = fixed, 2 = binary, 3 = floating point, 4 = --- N = optional
use
|
|
121 - 122
|
Instrument gain constant.
|
|
123 -
124
|
Instrument
early or initial gain (db).
|
|
125 - 126
|
Correlated: 1 = no 2 = yes
|
|
127 - 128
|
Sweep frequency at start.
|
|
129 - 130
|
Sweep frequency at end.
|
|
131 - 132
|
Sweep length,
ms.
|
|
133 - 134
|
Sweep type:
1 = linear 2 = parabolic 3 = exponential 4 = other
|
|
135 - 136
|
Sweep trace taper length at
start, ms.
|
|
137 - 138
|
Sweep trace taper length at
end, ms.
|
|
139 - 140
|
Taper type: 1 = linear 2 =
COs 3 = other
|
|
141 -
142
|
Alias
filter frequency.
|
|
143 -
144
|
Alias
filter slope.
|
|
145 - 146
|
Notch filter frequency.
|
|
147 - 148
|
Notch filter slope.
|
|
149 - 150
|
Low cut frequency.
|
|
151 - 152
|
High cut frequency.
|
|
153 - 154
|
Low cut slope.
|
|
155 - 156
|
High cut slope.
|
|
157 -
158
|
Year data
recorded (four digit integer).
|
|
159 - 160
|
Day of year.
|
|
161 -
162
|
Hour of
day (24 hour clock).
|
|
163 -
164
|
Minute
of hour.
|
|
165 -
166
|
Second
of minute.
|
|
167 - 168
|
Time basis
code: 1 = local 2 = GMT 3 = other
|
|
169 -
170
|
Trace
weighting factor - defined as 2-N volts for the least significant bit.
(N=0, 1,...,32,767)
|
|
171 - 172
|
Geophone group number of roll
switch position one.
|
|
173 - 174
|
Geophone group number of trace
number one within original field record.
|
|
175 - 176
|
Geophone group number of last
trace within original field record.
|
|
177 - 178
|
Gape size (total number of
groups dropped).
|
|
179 - 180
|
Overtravel associated with
taper at beginning or end of line: 1 = down (or behind) 2 = up (or ahead)
|
| 181 - 240 |
Unassigned - for optional
information. |
U.S. Department of the Interior |
U.S. Geological Survey