/* DEFINITION OF SEGY TRACE HEADER FOR LARSE EXPLOSION DATA. * * 16Dec94 Okaya/Ryberg Initial Definition (w/ Gary and Janice). * *============================================================================ * Lower case definitions are standard SEGY. * * UPPER CASE ARE RE-DEFINITIONS FOR LARSE EXPLOSION DATA. * */ Sierra size SEGY bytes GCV type ---- --------------- --- --- ------ -------------------------------- long lineSeq 1- 4 none Sequence number within line long reelSeq 5- 8 none Sequence number within reel long event_number 9- 12 kfldfn SHOT POINT INDEX# [1-63] long channel_number 13- 16 kfldtn SHOT GATHER TRACE INDEX# [1-XXXX] long energySourcePt 17- 20 kspct SP# NAME (e.g., 8170) long cdpEns 21- 24 kcdp common depth point number [EMPTY] long traceInEnsemble 25- 28 ktrace cdp trace number [EMPTY] short traceID 29- 30 ktrtyp SEGY Trace identification code: MAKE SURE IS SET TO "1" short vertSum 31- 32 kvsum DEPLOYMENT # (1, 2, or 3) short horSum 33- 34 khsum No. horizontally summed traces [EMPTY] short dataUse 35- 36 notuse 1 = production, 2 = test [EMPTY] long sourceToRecDist 37- 40 range SOURCE-RECEIVER OFFSET (SIGNED) long recElevation 41- 44 kgpel RECEIVER ELEVATION long sourceSurfElev 45- 48 kspel SOURCE ELEVATION long sourceDepth 49- 52 kspdp SOURCE DEPTH long datumElevRec 53- 56 kgpdat UTM RECEIVER X long datumElemSource 57- 60 kspdat UTM RECEIVER Y long sourceWaterDepth 61- 64 kspwdp UTM SOURCE X long recWaterDepth 65- 68 kgpwdp UTM SOURCE Y short elevationScale 69- 70 - should be set to 1. short coordScaler 71- 72 should be set to 1 long sourceLongOrX 73- 76 shotx DEC-DEG LONG SOURCE X (/100000.) long sourceLatOrY 77- 80 shoty DEC-DEG LAT SOURCE Y (/100000.) long recLongOrX 81- 84 rcvrx DEC-DEG LONG RECEIVER X (/100000.) long recLatOrY 85- 88 rcvry DEC-DEG LAT RECEIVER Y (/100000.) short coordUnits; 89- 90 kunits COORDINATE UNITS [CONSTANT AT 2] short weatheringVel 91- 92 kwtvel weathering velocity [EMPTY] short subWeathingVel 93- 94 kswevel Sub-weathering vel. [EMPTY] short sourceUpholeTime 95- 96 sptuh Uphole time source in microsec [EMPTY] short recUpholeTime 97- 98 gptuh Uphole time rec. in microsec [EMPTY] short sourceStaticCor 99-100 spst SOURCE STATIC (MSEC) short recStaticCor 101-102 gpst CLOCK CORRECTION (MSEC) short totalStatic 103-104 static TOTAL STATIC APPLIED (MSEC) short lagTimeA 105-106 kmslga Lag time A (msec) [EMPTY] short lagTimeB 107-108 kmslgb Lag time B [EMPTY] short delay 109-110 kmsfds DELAY RECORDING TIME (MSEC) short muteStart 111-112 fmute POLARITY (see below) short muteEnd 113-114 tmute ORIENTATION (see below) short sampleLength 115-116 knsamp #SAMPLES short deltaSample 117-118 sr SAMPLING INTERVAL IN MICROSEC short gainType 119-120 kgntyp FIELD SAMPLING INTERVAL IN MICROSEC short gainConst 121-122 kinsgn INSTRUMENT GAIN CONSTANT short initialGain 123-124 kgbn instrument inital gain in dB [EMPTY] short correlated 125-126 kcorcd COLOCATION STATION (0=NO, 1=YES) short sweepStart 127-128 kswfrs BOX (DAS) # short sweepLength 129-130 BOX TYPE (see below) short sweepType 131-132 GEOPHONE TYPE (see below) short sweepTaperAtStart 133-134 GEOPHONE # short sweepTaperAtEnd 135-136 STAKE # short taperType 137-138 COMPONENT (Z=1, N-S=2, E-W=3) short aliasFreq 141-142 kalhz alias filter frequency [EMPTY] short aliasSlope 143-144 kaldbo alias filter slope [EMPTY] short notchFreq 145-146 knthz SHOT TIME YEAR short notchSlope 147-148 kntdbo SHOT TIME DAY OF YEAR short lowCutFreq 149-150 klohz SHOT TIME HOUR short hiCutFreq 151-152 khihz SHOT TIME MINUTE short lowCutSlope 153-154 klodbo SHOT TIME SECOND short hiCutSlope 155-156 khidbo SHOT TIME MSEC short year 157-158 kyear TIME OF FIRST SAMPLE YEAR short day 159-160 kday TIME OF FIRST SAMPLE DAY short hour 161-162 khour TIME OF FIRST SAMPLE HOUR short minute 163-164 kminit TIME OF FIRST SAMPLE MINUTE short second 165-166 ksecnd TIME OF FIRST SAMPLE SECOND short timeBasisCode 167-168 ktmtyp TIME CODE [GMT=2] short traceWtingFactor 169-170 ktrwgt TIME OF FIRST SAMPLE MSEC short phoneRollPos1 171-172 kgprs1 PREMERGED TRACE INDEX (W/ COLOCs) short phoneFirstTrace 173-174 kgpbtr (MERGED) STATION TRACE INDEX short phoneLastTrace 175-176 kgpetr [EMPTY] short gapSize 177-178 gpgap [EMPTY] short taperOvertravel 179-180 lntpr taper 181-184 --- not used 185-188 krcdp receiver CDP of trace 189-192 kscdp source CDP number of trace 193-196 -- scalar for datum at CDP 197-198 kfold number of traces in CDP 199-200 ksset subset number of subline PASSCAL SEGY ---------- 201-204 sid shotpoint ID number | 205-208 sidcdp shotpoint ID at CDP | 209-212 kgpcdp receiver # at CDP | 213-216 ksecdp shotpoint elev at CDP | 217-220 kgecdp group point elev at CDP | 221-224 kswcdp shotpoint water depth at CDP | 225-226 sstcdp shotpoint static at CDP *1000 | 227-228 gpsc receiver static at CDP in sec | 229-232 ksdcdp shotpoint depth at CDP | 233-234 kspidx sequential shot index | 235-236 kgpidx sequential receiver index \ / short extrash[10] 181-200 long samp_rate 201-204 short data_form 205-206 short m_secs 207-208 short trigyear 209-210 short trigday 211-212 short trighour 213-214 short trigminute 215-216 short trigsecond 217-218 short trigmills 219-220 float scale_fac 221-224 short inst_no 225-226 short not_to_be_used 227-228 long num_samps 229-232 char extra[8] 233-240 }; /* end of segy trace header */ BYTES HEADER DESCRIPTION 9- 12 SHOT POINT INDEX# [1-63] See shot list in LARSE archive list (USC ftp site). 1-62= land shots 63 = Boron quarry blast 103-104 static TOTAL STATIC APPLIED (MSEC) = 0 if not static applied. != 0 amount of statics which have been applied. 109-110 kmsfds DELAY RECORDING TIME (MSEC) If tdelay = +2000. and the first data sample started at t0=0., the trace is pushed later in time and the original first sample now is at 2000. msec later than its original time. Due to static shifting, a new first sample will appear, and it will start at -2000 msec. before: (sec) 0 1 2 3 +---------+---------+----------+ after: -2 -1 0 1 +---------+---------+----------+ 111-112 fmute POLARITY (see below) 113-114 tmute ORIENTATION (see below) both: 0 = seismogram conforms to the defined standard below. 1 = problem exists, still needs to be corrected. -1 = problem corrected. STANDARD: 129-130 BOX TYPE (see below) SGR, PRS1, PRS4, REFTEKs, GEOS (code later) 131-132 GEOPHONE TYPE (see below) L28, L22, L10B (8.5 Hz), L4 (2 HZ), FBA 171-172 kgprs1 PREMERGED TRACE INDEX (W/ COLOCs) 173-174 kgpbtr (MERGED) STATION TRACE INDEX Premerged traces: Colocated traces have different trace #s. Components have same trace #. STATION trace index: Colocated traces have same trace #s. Components have same trace #.