CUPAGE FORMAT 00010004 C*********************************************************************** C COPYRIGHT ATLANTIC RICHFIELD COMPANY 1991 * C*********************************************************************** CUINDX 00020004 CUINDX DATA FORMATS 00030004 CU ARC-Y Format, Trace Header, Alphabetical 00040004 CU half-words are marked * 00050004 CU double-words are marked + 00060004 CU 00070004 CU Name Description Byte No.00080004 CU 00090004 CU THADPS Average depth-point static. *367- 36800100004 CU THAFF Alias filter frequency, if used. *141- 14200110004 CU THAFS Alias filter slope. *143- 14400120004 CU THAMPS AMPS source-reciever solution. *441- 44200130004 CU THAREJ AMPS trace reject flag. *443- 44400140004 CU THAR20 ARCO reserved word20. 481- 48400150004 CU THAR21 ARCO reserved word21. 485- 48800160004 CU THAR22 ARCO reserved word22. 489- 49200170004 CU THAR23 ARCO reserved word23. 493- 49600180004 CU THAR24 ARCO reserved word24. 497- 40000190004 CU THAR25 ARCO reserved word25. 501- 50400200004 CU THAR26 ARCO reserved word26. 505- 50800210004 CU THAR27 ARCO reserved word27. 509- 51200220004 CU THAR28 ARCO reserved word28. 513- 51600230004 CU THAR29 ARCO reserved word29. 517- 52000240004 CU THAR30 ARCO reserved word30. 521- 52400250004 CU THAR31 ARCO reserved word31. 525- 52800260004 CU THAR32 ARCO reserved word32. 529- 53200270004 CU THAR33 ARCO reserved word33. 533- 53600280004 CU THAR34 ARCO reserved word34. 537- 54000290004 CU THAR35 ARCO reserved word35. 541- 54400300004 CU THAR36 ARCO reserved word36. 545- 54800310004 CU THAR37 ARCO reserved word37. 549- 55200320004 CU THAR38 ARCO reserved word38. 553- 55600330004 CU THAR39 ARCO reserved word39. 557- 56000340004 CU THAR40 ARCO reserved word40. 561- 56400350004 CU THAR41 ARCO reserved word41. 565- 56800360004 CU THAR42 ARCO reserved word42. 569- 57200370004 CU THAR43 ARCO reserved word43. 573- 57600380004 CU THAR44 ARCO reserved word44. 577- 58000390004 CU THAR45 ARCO reserved word45. 581- 58400400004 CU THAR46 ARCO reserved word46. 585- 58800410004 CU THAR47 ARCO reserved word47. 589- 59200420004 CU THAR48 ARCO reserved word48. 593- 59600430004 CU THAR49 ARCO reserved word49. 597- 60000440004 CU THAR50 ARCO reserved word50. 601- 60400450004 CU THAR51 ARCO reserved word51. 605- 60800460004 CU THAR52 ARCO reserved word52. 609- 61200470004 CU THAR53 ARCO reserved word53. 613- 61600480004 CU THAR54 ARCO reserved word54. 617- 62000490004 CU THAR55 ARCO reserved word55. 621- 62400500004 CU THAR56 ARCO reserved word56. 625- 62800510004 CU EJECT 00520004 CU THAR57 ARCO reserved word57. 629- 63200530004 CU THAR58 ARCO reserved word58. 633- 63600540004 CU THAR59 ARCO reserved word59. 637- 64000550004 CU THAR60 ARCO reserved word60. 641- 64400560004 CU THAR61 ARCO reserved word61. 645- 64800570004 CU THAR62 ARCO reserved word62. 649- 65200580004 CU THAR63 ARCO reserved word63. 653- 65600590004 CU THAR64 ARCO reserved word64. 657- 66000600004 CU THAR69 ARCO reserved word69. 293- 29600650004 CU THAR70 ARCO reserved word70. 297- 30000660004 CU THAR71 ARCO reserved halfword71. *301- 30200670004 CU THAR72 ARCO reserved halfword72. *303- 30400680004 CU THAR73 ARCO reserved word73. 305- 30800690004 CU THAR74 ARCO reserved word74. 309- 31200700004 CU THASD Average shot depth. *363- 36400710004 CU THBGRV Bouger gravity measurement *665- 66606750004 CU THCDPL Cdp line location number 335- 33800720004 CU THCDPN Cdp ensemble number. 21- 2400730004 CU THCDPT Trace number within the cdp ensemble -- each 25- 2800740004 CU ensemble starts with trace number one. 00750004 CU THCOR Correlated: 1 = no, 2 = yes. *125- 12600760004 CU THCRST Calculated group static correction. 433- 43600770004 CU This variable is used to pass a receiver static 00780004 CU correction, calculated by process STAT, between 00790004 CU the PREP and PROC steps. Its value will be as- 00800004 CU signed to the trace header variable, THRST, at 00810004 CU the time of actual application of a static cor- 00820004 CU rection to the data. 00830004 CU THCSST Calculated source static correction. 429- 43200840004 CU This variable is used to pass a shot static 00850004 CU correction, calculated by process STAT, between 00860004 CU the PREP and PROC steps. Its value will be as- 00870004 CU signed to the trace header variable, THSST, at 00880004 CU the time of actual application of a static cor- 00890004 CU rection to the data. 00900004 CU THCUCD XY coordinate units (1 = meters or feet, *89- 9000910004 CU 2 = sec. of arc) 00920004 CU THCUPI In-line coupling fraction to next CDP fl pt r4 445- 44800930004 CU THCUPX Cross-line coupling fraction to next line fl pt r4 457- 46000940004 CU THDAY Day of year. *159- 16000950004 CU THDELR Datum elevation at receiver group. 53- 5600960004 CU THDELS Datum elevation at source. 57- 6000970004 CU THDPDE Depth point datum elevation. 343- 34600980004 CU THDMDZ Depth migration depth step (feet or meters). fl r4 673- 67600980005 CU THDPEL Depth point elevation. 281- 28400990004 CU THDPNS Depth point nearest the shotpoint no. (THSSP), 401- 40401000004 CU (changed by read process to shotpoint nearest 01010004 CU the depth point (THCDPN)). 01020004 CU THDPWD Depth point water depth. 285- 28801030004 CU EJECT 01040004 CU THDPXC Depth point x-coordinate. 273- 27601050004 CU THDPYC Depth point y-coordinate. 277- 28001060004 CU THDRT Delay recording time. Time in ms. between init- *109- 11001070004 CU iation time of the energy source and time when 01080004 CU recording of data samples begins. (For deep water 01090004 CU work if data recording does not start at zero time). 01100004 CU THEIGN Instrument early or initial gain (db). *123- 12401110004 CU THEREF Elevation of the refractor. 677- 68001120004 CU THESPN Energy source point number -- used when more than 17- 2001130004 CU one record occurs at the same effective surface 01140004 CU location. 01150004 CU THFLV Index of first live value, counting from the *321- 32201160004 CU beginning of the trace (Fortran index). 01170004 CU THFN File number (internal shot number assigned *249- 25001180004 CU during pip). 01190004 CU THFRDS Floating residual depth point static fl pt r4 193- 19601200004 CU THFRES Floating residual static shift (ms). fl pt r4 421- 42401210004 CU THFRMS Floating residual move-out static fl pt r4 197- 20001220004 CU THFRRS Floating residual receiver static fl pt r4 189- 19201230004 CU THFRSC Floating correlation time lag (ms). fl pt r4 181- 18401240004 CU THFRSS Floating residual shot static fl pt r4 185- 18801250004 CU THFTST Floating total static applied (ms). fl pt r4 397- 40001260004 CU (zero if no static has been applied). 01270004 CU used in place of 'THTST' throughout SPARC. 01280004 CU THGATH Used by gather processor as disk address pointer 241- 24401290004 CU THGCRP Used by GM3D as disk address pointer for a 339- 34201300004 CU common receiver sort. 01310004 CU THGNC Instrument gain constant. *121- 12201320004 CU THGNTL Geophone group number of last trace within *175- 17601330004 CU original field record. 01340004 CU THGNTY Gain type of field instruments: 1 = fixed *119- 12001350004 CU 2 = binary 01360004 CU 3 = floating point 01370004 CU 4 to 32767 = optional use 01380004 CU THGNT1 Geophone group number of trace number one within *173- 17401390004 CU original field record. 01400004 CU THGRSI Receiver station interval (percent). *359- 36001410004 CU THGRS1 Geophone group number of roll switch position one. *171- 17201420004 CU THGSZ Gap size (total number of groups dropped). *177- 17801430004 CU THHCF High cut frequency, if used. *151- 15201440004 CU THHCS High cut slope. *155- 15601450004 CU THHOUR Hour of day (24 hour clock). *161- 16201460004 CU THL Trace header length (words). *245- 24601470004 CU THLCF Low cut frequency, if used. *149- 15001480004 CU THLCS Low cut slope. *153- 15401490004 CU THLGTR Lagging trace number. *331- 33201500004 CU THLMDA AMPS offset solution. fl pt r4 449- 45201510004 CU THLNAM Shot line name (alphanumeric). +377- 38401520004 CU THLNBG Line bearing (degrees from north). fl pt r4 385- 38801530004 CU THLNNO 3D line number. *361- 36201540004 CU EJECT 01550004 CU THLNTP 3D line type. 0 = normal, 1 = xline, *369- 37001560004 CU 2 = upward diagonal, 3 = downward diagonal. 01570004 CU THLRES Resid static applied last TRAC iteration fl pt r4 453- 45601580004 CU THLTA Lag time a. Time in ms. between end of 240 byte *105- 10601590004 CU trace identification header and time break. 01600004 CU Positive if time break occurs after end of header 01610004 CU and negative if time break occurs before end of 01620004 CU header. Time break is defined as the initiation 01630004 CU pulse which may be recorded on an auxiliary trace 01640004 CU or as otherwise specified by the recording system. 01650004 CU THLTB Lag time b. Time in ms. between time break and *107- 10801660004 CU the initiation time of the energy source. May 01670004 CU be positive or negative. 01680004 CU THMAV Absolute average amplitude. fl pt r4 661- 66401690004 CU THMDPX Mean depth point x-coordinate. 351- 35401690004 CU THMDPY Mean depth point y-coordinate. 355- 35801700004 CU THMIN Minute of hour. *163- 16401710004 CU THMPDV Velocity increment used for pre-stack FK mig (MPFK) 461- 46401720004 CU THMPMV Min/start velocity used for pre-stack FK mig (MPFK) 465- 46801730004 CU THMPNV Number of vels used for pre-stack FK mig (MPFK) 469- 47201740004 CU THMPPF Velocity increment type flag for MPFK. 473- 47601750004 CU 0 = Velocity increment is THMPDV ft/sec. 01760004 CU 1 = Velocity increment is THMPDV % increase 01770004 CU THMTE Mute time--end *113- 11401780004 CU THMTL Muting taper length (ms). *289- 29001790004 CU THMTS Mute time--start *111- 11201800004 CU THMTTC Muting taper type code (1 = linear,... ). *291- 29201810004 CU THNDPS Number of depth points. 413- 41601820004 CU THNFF Notch filter frequency, if used. *145- 14601830004 CU THNFS Notch filter slope. *147- 14801840004 CU THNGPS Number of receiver stations. 405- 40801850004 CU THNHST Number of horizontally stacked traces yielding *33- 3401860004 CU this trace. (1 is one trace, 2 is two stacked 01870004 CU traces, etc.) 01880004 CU THNMF Normal moveout application flag. *315- 31601890004 CU THNS Number of samples in this trace. *115- 11601900004 CU THNSSP Number of shotpoints on the line. 255- 25801910004 CU THNTCR Number of traces in common receiver ensemble. *269- 27001920004 CU THNTDP Number of traces in cdp ensemble. *271- 27201930004 CU THNVST Number of vertically summed traces yielding this *31- 3201940004 CU trace. (1 is one trace, 2 is two summed traces, 01950004 CU etc.) 01960004 CU THORRN Original record no. from field tape. 9- 1201970004 CU THORTN Trace number within the original field record. 13- 1601980004 CU THOT Over travel associated with taper at beginning *179- 18001990004 CU or end of line. 1 = down (or behind), 02000004 CU 2 = up (or ahead ). 02010004 CU THPICK Refraction statics Pick File time. fl pt r4 425- 42802020004 CU This value includes the total static value and 02030004 CU is stored and used by STAP to back out the 02040004 CU refraction Pick File static. 02050004 CU THPOL Polarity of the trace (1 = normal, 2 = reversed). *313- 31402060004 CU EJECT 02070004 CU THRCLN Receiver line location number. 265- 26802080004 CU THRCNO Receiver number. 477- 48002090004 CU THRGEL Receiver group elevation. Elevations above 41- 4402100004 CU sea level are positive and below sea level are 02110004 CU negative. 02120004 CU THRGRV Residual gravity *667- 66806760004 CU THRMAG Filtered intensity measurement *671- 67206760004 CU THRNMF Residual normal moveout application flag. *317- 31802130004 CU THRSST Residual static shift for this trace (ms). *319- 32002140004 CU THRST Group static correction. *101- 10202150004 CU THRTUH Group uphole time. *97- 9802160004 CU THRXC Group coordinate-x | meridian or north of the 81- 8402170004 CU | equator and a negative value 02180004 CU | designates the number of sec. 02190004 CU THRYC Group coordinate-y | south or west. 85- 8802200004 CU THSCLC Scaler to be applied to all coordinates specified *71- 7202210004 CU in bytes 73-88 to give the real value. 02220004 CU Scaler = 1, +-10, +-100, +-1000, or +-10000. 02230004 CU If positive, scaler is used as a multiplier, if 02240004 CU negative, scaler is used as a divisor. 02250004 CU THSCLE Scaler to be applied to all elevations and depths *69- 7002260004 CU Specified in bytes 41-68 to give the real value. 02270004 CU Scaler = 1,+-10,+-100,+-1000, or +-10000. 02280004 CU If positive, scaler is used as a multiplier, if 02290004 CU negative, scaler is used as a divisor. 02300004 CU THSDPN Starting depth point number. 409- 41202310004 CU THSDPT Source depth below surface (a positive number). 49- 5202320004 CU THSEC Second of minute. *165- 16602330004 CU THSEQL Trace sequence no. for this line -- 1- 402340004 CU numbers continue to increase if additional reels 02350004 CU are required on same line. 02360004 CU THSEQR Shotpoint sequence number for this line. 5- 802370004 CU THSI Sample interval in microseconds for this trace *117- 11802380004 CU THSLN Source line location number. 259- 26202390004 CU THSMDE Stat computed mean depth point datum elevation 373- 37602400004 CU THSPDP Depth point spacing. fl pt r4 347- 35002410004 CU THSPLN 3D line spacing. fl pt r4 389- 39202420004 CU THSRXC Source coordinate-x | if the coordinate units are in 73- 7602430004 CU | seconds of arc the x values 02440004 CU | represent longitude and the 02450004 CU THSRYC Source coordinate-y | y values latitude. A positive 77- 8002460004 CU | value designates the number of 02470004 CU | sec. east of greenwich 02480004 CU THSSEL Surface elevation at source. 45- 4802490004 CU THSSP Shotpoint number. 251- 25402500004 CU THSST Source static correction. *99- 10002510004 CU THSTGS Starting receiver station no. 417- 42002520004 CU THSTUH Source uphole time. *95- 9602530004 CU THSWFE Sweep frequency at end. *129- 13002540004 CU THSWFS Sweep frequency at start. *127- 12802550004 CU THSWL Sweep length in ms. *131- 13202560004 CU EJECT 02570004 CU THSWTE Sweep trace taper length at end in ms. *137- 13802580004 CU THSWTS Sweep trace taper length at start in ms. *135- 13602590004 CU THSWTT Taper type: 1 = linear, 2 = COS**2, 3 = other. *139- 14002600004 CU THSWTY Sweep type: 1 = linear, 2 = parabolic, *133- 13402610004 CU 3 = exponential, 4 = other. 02620004 CU THSWV Subweathering velocity. *93- 9402630004 CU THSYR0 SEGY reserved word0 201- 20402640004 CU THSYR1 SEGY reserved word1 205- 20802650004 CU THSYR2 SEGY reserved word2 209- 21202660004 CU THSYR3 SEGY reserved word3 213- 21602670004 CU THSYR4 SEGY reserved word4 217- 22002680004 CU THSYR5 SEGY reserved word5 221- 22402690004 CU THSYR6 SEGY reserved word6 225- 22802700004 CU THSYR7 SEGY reserved word7 229- 23202710004 CU THSYR8 SEGY reserved word8 233- 23602720004 CU THSYR9 SEGY reserved word9 237- 24002730004 CU THTAZI 3D trace azimuth (degrees from north). fl pt r4 393- 39602740004 CU THTBC Time basis code: 1 = local, 2 = gmt, 3 = other. *167- 16802750004 CU THTICD Trace identification code. *29- 3002760004 CU THTMAG Magnetic intensity measurement *669- 67006750004 CU THTRAC Reserved for use by TRAC. fl pt r4 437- 44002770004 CU THTST Total static applied (msec). (Zero if no static *103- 10402780004 CU has been applied.) This field not used 02790004 CU directly within SPARC. 02800004 CU THTWF Trace weighting factor--defined as 2**-n volts *169- 17002810004 CU for the least significant bit. (n=o,1,...,32767) 02820004 CU THUSCD Data set sequence number (within a job). *35- 3602830004 CU THVBDA VSP borehole declenation (degrees). fl pt r4 721- 72402840004 CU THVBIA VSP borehole inclination (degrees). fl pt r4 717- 72002850004 CU THVER Version no. *247- 24802860004 CU THVKBE VSP kb elevation (ft). 693- 69602870004 CU THVLDR VSP log depth reference (ft). 685- 68802880004 CU THVOTA VSP original trace azimuth (degrees). fl pt r4 729- 73202890004 CU THVOTI VSP original trace inclination (degrees). fl pt r4 725- 72802900004 CU THVPMT VSP p measured time (microsec). 705- 70802910004 CU THVPVT VSP p vertical time (microsec). 701- 70402920004 CU THVRLD VSP receiver depth (ft). 681- 68402930004 CU THVRTA VSP rotated trace azimuth (degrees). fl pt r4 737- 74002940004 CU THVRTI VSP rotated trace inclination (degrees). ft pt r4 733- 73602950004 CU THVSMT VSP s measured time (microsec). 713- 71602960004 CU THVSVT VSP s vertical time (microsec). 709- 71202970004 CU THVTCN VSP trace component number. *365- 36602980004 CU THVTVD VSP receiver tvd depth (ft). 689- 69202990004 CU THVWHE VSP ground elevation (ft). 697- 70003000004 CU THWATV Water velocity. *323- 32403010004 CU THWDPR Water depth at group. 65- 6803020004 CU THWDPS Water depth at source. 61- 6403030004 CU THWGID WATR Western identification number. 741- 74403040004 CU EJECT 03050004 CU THWGNM WATR Western wavename (alphanumeric). 745- 74803060004 CU THWGTN WATR Western trace number. *371- 37203070004 CU THWV Weathering velocity. *91- 9203080004 CU THWVET WATR wavelet end time (ms). 753- 75603090004 CU THWVRT WATR first sample time (ms). 757- 76003100004 CU THWVST WATR wavelet start time (ms). 749- 75203110004 CU THXDST Distance from source point to receiver group. 37- 4003120004 CU THYEAR Year data recorded. *157- 15803130004 CUEND 03140004 CU ARC-Y Format, Trace Header 03150004 CU Follows SEG-Y format through byte 240. 03160004 CU ARC-Y additions begin at byte 241. 03170004 CU length = 760 bytes = 190 words. 03180004 CU 03190004 CU Name Description Byte No.03200004 CU 03210004 CU THSEQL Trace sequence no. for this line -- numbers 1- 403220004 CU continue to increase if additional reels are 03230004 CU required on same line. 03240004 CU THSEQR Shotpoint sequence number for this line. 5- 803250004 CU THORRN Original record no. from field tape. 9- 1203260004 CU THORTN Trace number within the original field record. 13- 1603270004 CU THESPN Energy source point number -- used when more than 17- 2003280004 CU one record occurs at the same effective surface 03290004 CU location. 03300004 CU THCDPN Cdp ensemble number. 21- 2403310004 CU THCDPT Trace number within the cdp ensemble -- each 25- 2803320004 CU ensemble starts with trace number one. 03330004 CU THTICD Trace identification code. *29- 3003340004 CU 1 = seismic data 03350004 CU 2 = dead 03360004 CU 3 = dummy 03370004 CU 4 = time break 03380004 CU 5 = uphole 03390004 CU 6 = sweep 03400004 CU 7 = timing 03410004 CU 8 = water break 03420004 CU 9 = autocorrelation 03430004 CU 10 = velocity semblance data 03440004 CU 11 = rms velocity function trace 03450004 CU 12 = rms iso-velocity gradient trace 03460004 CU 13 = sel auxiliary 03470004 CU 14 = retrocorrelation 03480004 CU 15 = QUAD amplitude 03490004 CU 16 = QUAD phase 03500004 CU 17 = QUAD instantaneous frequency 03510004 CU 18 = QUAD weighted frequency 03520004 CU 19 = information (R & D) 03530004 CU 20 = QUAD real inverse transform 03540004 CU 21 = QUAD imaginary inverse transform 03550004 CU 22 = invalid trace number 03560004 CU 23 = continuous rms velocity 03570004 CU 24 = continuous interval velocity 03580004 CU 25 = mnvd seismic wavelets 03590004 CU 26 = interpolated seismic trace 03600004 CU 27 = source signature 03610004 CU 28 = digicon file header 03620004 CU 29 = digicon file trailer 03630004 CU 30 = receiver statics plot information 03640004 CU 31 = shot statics plot information 03650004 CU 32 = field file header auxiliary trace 03660004 CU 33 = unclassified 03670004 CU EJECT 03680004 CU THTICD continued 03690004 CU 34 = cepstra and summed cepstra from SCDA 03700004 CU 35 = cepstra, summed cepstra, and decomposed 03710004 CU cepstra from SCDB 03720004 CU 36 = wavelet computed by direct deconvolution 03730004 CU 37 = CNAX velocity trace 03740004 CU 38 = TRAC statics solution 03750004 CU 39 = unclassified 03760004 CU 40 = unclassified 03770004 CU 41 = TRAX statics solution 03780004 CU 42 = LITH product trace 03790004 CU 43 = LITH intercept trace 03800004 CU 44 = LITH slope trace 03810004 CU 45 = LITH Y trace 03820004 CU 46 = LITH XISADD trace 03830004 CU 47 = LITH correlation coefficient trace 03840004 CU 48 = HZAD input semblance trace 03850004 CU 49 = TRAK output pilot trace 03860004 CU 50 = AIED edit attributes 03870004 CU 51 = LITH intercept * sign of stacked trace 03880004 CU 52 to 32767, not assigned. 03890004 CU THNVST Number of vertically summed traces yielding this *31- 3203900004 CU trace. (1 is one trace, 2 is two summed traces, 03910004 CU etc.) 03920004 CU THNHST Number of horizontally stacked traces yielding *33- 3403930004 CU this trace. (1 is one trace, 2 is two stacked 03940004 CU traces, etc.) 03950004 CU THUSCD Data set sequence number (within a job). *35- 3603960004 CU THXDST Distance from source point to receiver group 37- 4003970004 CU THRGEL Receiver group elevation. Elevations above sea 41- 4403980004 CU level are positive and below sea level are 03990004 CU negative. 04000004 CU THSSEL Surface elevation at source. 45- 4804010004 CU THSDPT Source depth below surface (a positive number). 49- 5204020004 CU THDELR Datum elevation at receiver group. 53- 5604030004 CU THDELS Datum elevation at source. 57- 6004040004 CU THWDPS Water depth at source. 61- 6404050004 CU THWDPR Water depth at group. 65- 6804060004 CU THSCLE Scaler to be applied to all elevations and depths *69- 7004070004 CU specified in bytes 41-68 to give the real value. 04080004 CU Scaler = 1,+-10,+-100,+-1000, or +-10000. 04090004 CU If positive, scaler is used as a multiplier, if 04100004 CU negative, scaler is used as a divisor. 04110004 CU THSCLC Scaler to be applied to all coordinates specified *71- 7204120004 CU in bytes 73-88 to give the real value. 04130004 CU Scaler = 1, +-10, +-100, +-1000, or +-10000. 04140004 CU If positive, scaler is used as a multiplier, if 04150004 CU negative, scaler is used as a divisor. 04160004 CU EJECT 04170004 CU THSRXC Source coordinate-x | if the coordinate units are in 73- 7604180004 CU | seconds of arc the x values 04190004 CU | represent longitude and the 04200004 CU THSRYC Source coordinate-y | y values latitude. A positive 77- 8004210004 CU | value designates the number of 04220004 CU | sec. east of greenwich 04230004 CU THRXC Group coordinate-x | meridian or north of the 81- 8404240004 CU | equator and a negative value 04250004 CU | designates the number of sec. 04260004 CU THRYC Group coordinate-y | south or west. 85- 8804270004 CU THCUCD XY coordinate units (1 = meters or feet, *89- 9004280004 CU 2 = sec. of arc) 04290004 CU THWV Weathering velocity. *91- 9204300004 CU THSWV Subweathering velocity. *93- 9404310004 CU THSTUH Source uphole time. *95- 9604320004 CU THRTUH Group uphole time. *97- 9804330004 CU THSST Source static correction. *99- 10004340004 CU THRST Group static correction. *101- 10204350004 CU THTST Total static applied (ms). (Zero if no static *103- 10404360004 CU has been applied.) This field not used 04370004 CU directly within SPARC. 04380004 CU THLTA Lag time a. Time in ms. between end of 240 byte *105- 10604390004 CU trace identification header and time break. 04400004 CU Positive if time break occurs after end of header 04410004 CU and negative if time break occurs before end of 04420004 CU header. Time break is defined as the initiation 04430004 CU pulse which may be recorded on an auxiliary trace 04440004 CU or as otherwise specified by the recording system. 04450004 CU THLTB Lag time b. Time in ms. between time break and *107- 10804460004 CU the initiation time of the energy source. May 04470004 CU be positive or negative. 04480004 CU THDRT Delay recording time. Time in ms. between *109- 11004490004 CU initiation time of the energy source and time when 04500004 CU recording of data samples begins. (For deep water 04510004 CU work if data recording does not start at zero time). 04520004 CU THMTS Mute time--start *111- 11204530004 CU THMTE Mute time--end *113- 11404540004 CU THNS Number of samples in this trace. *115- 11604550004 CU THSI Sample interval in microseconds for this trace *117- 11804560004 CU THGNTY Gain type of field instruments: 1 = fixed *119- 12004570004 CU 2 = binary 04580004 CU 3 = floating point 04590004 CU 4 to 32767 = optional use 04600004 CU THGNC Instrument gain constant. *121- 12204610004 CU THEIGN Instrument early or initial gain (db). *123- 12404620004 CU THCOR Correlated: 1 = no, 2 = yes. *125- 12604630004 CU THSWFS Sweep frequency at start. *127- 12804640004 CU THSWFE Sweep frequency at end. *129- 13004650004 CU THSWL Sweep length in ms. *131- 13204660004 CU THSWTY Sweep type: 1 = linear, 2 = parabolic, *133- 13404670004 CU 3 = exponential, 4 = other. 04680004 CU EJECT 04690004 CU THSWTS Sweep trace taper length at start in ms. *135- 13604700004 CU THSWTE Sweep trace taper length at end in ms. *137- 13804710004 CU THSWTT Taper type: 1 = linear, 2 = COS**2, 3 = other. *139- 14004720004 CU THAFF Alias filter frequency, if used. *141- 14204730004 CU THAFS Alias filter slope. *143- 14404740004 CU THNFF Notch filter frequency, if used. *145- 14604750004 CU THNFS Notch filter slope. *147- 14804760004 CU THLCF Low cut frequency, if used. *149- 15004770004 CU THHCF High cut frequency, if used. *151- 15204780004 CU THLCS Low cut slope. *153- 15404790004 CU THHCS High cut slope. *155- 15604800004 CU THYEAR Year data recorded. *157- 15804810004 CU THDAY Day of year. *159- 16004820004 CU THHOUR Hour of day (24 hour clock). *161- 16204830004 CU THMIN Minute of hour. *163- 16404840004 CU THSEC Second of minute. *165- 16604850004 CU THTBC Time basis code: 1 = local, 2 = gmt, 3 = other. *167- 16804860004 CU THTWF Trace weighting factor--defined as 2**-n volts *169- 17004870004 CU for the least significant bit. (n=0,1,...,32767) 04880004 CU THGRS1 Geophone group number of roll switch position one. *171- 17204890004 CU THGNT1 Geophone group number of trace number one within *173- 17404900004 CU original field record. 04910004 CU THGNTL Geophone group number of last trace within *175- 17604920004 CU original field record. 04930004 CU THGSZ Gap size (total number of groups dropped). *177- 17804940004 CU THOT Over travel associated with taper at beginning *179- 18004950004 CU or end of line. 1 = down (or behind), 04960004 CU 2 = up (or ahead ). 04970004 CU THFRSC Floating correlation time lag (ms). fl pt r4 181- 18404980004 CU THFRSS Floating residual shot static fl pt r4 185- 18804990004 CU THFRRS Floating residual receiver static fl pt r4 189- 19205000004 CU THFRDS Floating residual depthpoint static fl pt r4 193- 19605010004 CU THFRMS Floating residual move-out static fl pt r4 197- 20005020004 CU THSYR0 SEGY reserved word0 201- 20405030004 CU THSYR1 SEGY reserved word1 205- 20805040004 CU THSYR2 SEGY reserved word2 209- 21205050004 CU THSYR3 SEGY reserved word3 213- 21605060004 CU THSYR4 SEGY reserved word4 217- 22005070004 CU THSYR5 SEGY reserved word5 221- 22405080004 CU THSYR6 SEGY reserved word6 225- 22805090004 CU THSYR7 SEGY reserved word7 229- 23205100004 CU THSYR8 SEGY reserved word8 233- 23605110004 CU THSYR9 SEGY reserved word9 237- 24005120004 CU 05130004 CU End of SEG-Y trace header. ARCO additions follow. 05140004 CU EJECT 05150004 CU ARCO additions to SEG-Y trace header. 05160004 CU 05170004 CU THGATH Used by gather processor as disk address pointer 241- 24405180004 CU THL Trace header length (words). *245- 24605190004 CU THVER Version no. *247- 24805200004 CU THFN File number (internal shot number assigned *249- 25005210004 CU during pip). 05220004 CU THSSP Shotpoint number. 251- 25405230004 CU THNSSP Number of shotpoints on the line. 255- 25805240004 CU THSLN Source line location number. 259- 26205250004 CU THDPNS Depth point nearest the shotpoint no. (THSSP), *263- 26405260004 CU (changed by read process to shotpoint nearest 05270004 CU the depth point (THCDPN)). (See Note 1) 05280004 CU THRCLN Receiver line location number. 265- 26805290004 CU THNTCR Number of traces in common receiver ensemble. *269- 27005300004 CU THNTDP Number of traces in cdp ensemble. *271- 27205310004 CU THDPXC Depth point x-coordinate. 273- 27605320004 CU THDPYC Depth point y-coordinate. 277- 28005330004 CU THDPEL Depth point elevation. 281- 28405340004 CU THDPWD Depth point water depth. 285- 28805350004 CU THMTL Muting taper length (ms). *289- 29005360004 CU THMTTC Muting taper type code (1 = linear,... ). *291- 29205370004 CU THAR69 ARCO reserved word69. 293- 29605380004 CU THAR70 ARCO reserved word70. 297- 30005390004 CU THAR71 ARCO reserved halfword71. *301- 30205400004 CU THAR72 ARCO reserved halfword72. *303- 30405410004 CU THAR73 ARCO reserved word73. 305- 30805420004 CU THAR74 ARCO reserved word74. 309- 31205430004 CU THPOL Polarity of the trace (1 = normal, 2 = reversed). *313- 31405440004 CU THNMF Normal moveout application flag. *315- 31605450004 CU THRNMF Residual normal moveout application flag. *317- 31805460004 CU THRSST Residual static shift for this trace (ms). *319- 32005470004 CU THFLV Index of first live value, counting from the *321- 32205480004 CU beginning of the trace (fortran index). 05490004 CU THWATV Water velocity. *323- 32405500004 CU THNGPS Number of receiver stations. (See Note 1) *325- 32605510004 CU THSDPN Starting depth point number. (See Note 1) *327- 32805520004 CU THNDPS Number of depth points. (see Note 1) *329- 33005530004 CU THLGTR Lagging trace number. *331- 33205540004 CU THSTGS Starting receiver station no. (See Note 1) *333- 33405550004 CU THCDPL Cdp line location number 335- 33805560004 CU THGCRP Used by GM3D as disk address pointer for a 339- 34205570004 CU common receiver sort. 05580004 CU THDPDE Depth point datum elevation. 343- 34605590004 CU THSPDP Depth point spacing. fl pt r4 347- 35005600004 CU THMDPX Mean depth point x-coordinate. 351- 35405610004 CU THMDPY Mean depth point y-coordinate. 355- 35805620004 CU THGRSI Receiver station interval (percent). *359- 36005630004 CU THLNNO 3D line number. *361- 36205640004 CU THASD Average shot depth. *363- 36405650004 CU EJECT 05660004 CU THVTCN VSP trace component number. *365- 36605670004 CU THADPS Average depth-point static. *367- 36805680004 CU THLNTP 3D line type. 0 = normal, 1 = xline, *369- 37005690004 CU 2 = upward diagonal, 3 = downward diagonal. 05700004 CU THWGTN WATR Western trace number. *371- 37205710004 CU THSMDE Stat computed mean depth point datum elevation 373- 37605720004 CU THLNAM Shot line name (alphanumeric). +377- 38405730004 CU 05740004 CU The following ARCO additions were added to the seismic 05750004 CU trace headers on 9/04/84. ARC-Y trace headers prior 05760004 CU to that date are 96 words (384 bytes) long and after 05770004 CU that date they are 190 words (760 bytes) long. 05780004 CU 05790004 CU 05800004 CU THLNBG Line bearing (degrees from north). fl pt r4 385- 38805810004 CU THSPLN 3D line spacing. fl pt r4 389- 39205820004 CU THTAZI 3D trace azimuth (degrees from north). fl pt r4 393- 39605830004 CU THFTST Floating total static applied (ms). fl pt r4 397- 40005840004 CU (zero if no static has been applied). 05850004 CU Used in place of 'THTST' throughout SPARC. 05860004 CU THDPNS Depth point nearest the shotpoint no. (THSSP), 401- 40405870004 CU (changed by read process to shotpoint nearest 05880004 CU the depth point (THCDPN)). 05890004 CU THNGPS Number of receiver stations. 405- 40805900004 CU THSDPN Starting depth point number. 409- 41205910004 CU THNDPS Number of depth points. 413- 41605920004 CU THSTGS Starting receiver station no. 417- 42005930004 CU THFRES Floating residual static shift (ms). fl pt r4 421- 42405940004 CU THPICK Refraction statics Pick File time. fl pt r4 425- 42805950004 CU This value includes the total static value and 05960004 CU is stored and used by STAP to back out the 05970004 CU refraction Pick File static. 05980004 CU THCSST Calculated source static correction. 429- 43205990004 CU This variable is used to pass a shot static 06000004 CU correction, calculated by process STAT, between 06010004 CU the PREP and PROC steps. Its value will be as- 06020004 CU signed to the trace header variable, THSST, at 06030004 CU the time of actual application of a static cor- 06040004 CU rection to the data. 06050004 CU THCRST Calculated group static correction. 433- 43606060004 CU This variable is used to pass a receiver static 06070004 CU correction, calculated by process STAT, between 06080004 CU the PREP and PROC steps. Its value will be as- 06090004 CU signed to the trace header variable, THRST, at 06100004 CU the time of actual application of a static cor- 06110004 CU rection to the data. 06120004 CU THTRAC Reserved for use by TRAC. fl pt r4 437- 44006130004 CU THAMPS AMPS source-reciever solution. *441- 44206140004 CU THAREJ AMPS trace reject flag. *443- 44406150004 CU EJECT 06160004 CU THCUPI In-line coupling fraction to next CDP fl pt r4 445- 44806170004 CU THLMDA AMPS offset solution. fl pt r4 449- 45206180004 CU THLRES Resid static applied last TRAC iteration fl pt r4 453- 45606190004 CU THCUPX Cross-line coupling fraction to next line fl pt r4 457- 46006200004 CU THMPDV Velocity increment used for pre-stack FK mig (MPFK) 461- 46406210004 CU THMPMV Min/start velocity used for pre-stack FK mig (MPFK) 465- 46806220004 CU THMPNV Number of vels used for pre-stack FK mig (MPFK) 469- 47206230004 CU THMPPF Velocity increment type flag for MPFK. 473- 47606240004 CU 0 = Velocity increment is THMPDV ft/sec. 06250004 CU 1 = Velocity increment is THMPDV % increase 06260004 CU THRCNO Receiver number. 477- 48006270004 CU THAR20 ARCO reserved word20. 481- 48406280004 CU THAR21 ARCO reserved word21. 485- 48806290004 CU THAR22 ARCO reserved word22. 489- 49206300004 CU THAR23 ARCO reserved word23. 493- 49606310004 CU THAR24 ARCO reserved word24. 497- 40006320004 CU THAR25 ARCO reserved word25. 501- 50406330004 CU THAR26 ARCO reserved word26. 505- 50806340004 CU THAR27 ARCO reserved word27. 509- 51206350004 CU THAR28 ARCO reserved word28. 513- 51606360004 CU THAR29 ARCO reserved word29. 517- 52006370004 CU THAR30 ARCO reserved word30. 521- 52406380004 CU THAR31 ARCO reserved word31. 525- 52806390004 CU THAR32 ARCO reserved word32. 529- 53206400004 CU THAR33 ARCO reserved word33. 533- 53606410004 CU THAR34 ARCO reserved word34. 537- 54006420004 CU THAR35 ARCO reserved word35. 541- 54406430004 CU THAR36 ARCO reserved word36. 545- 54806440004 CU THAR37 ARCO reserved word37. 549- 55206450004 CU THAR38 ARCO reserved word38. 553- 55606460004 CU THAR39 ARCO reserved word39. 557- 56006470004 CU THAR40 ARCO reserved word40. 561- 56406480004 CU THAR41 ARCO reserved word41. 565- 56806490004 CU THAR42 ARCO reserved word42. 569- 57206500004 CU THAR43 ARCO reserved word43. 573- 57606510004 CU THAR44 ARCO reserved word44. 577- 58006520004 CU THAR45 ARCO reserved word45. 581- 58406530004 CU THAR46 ARCO reserved word46. 585- 58806540004 CU THAR47 ARCO reserved word47. 589- 59206550004 CU THAR48 ARCO reserved word48. 593- 59606560004 CU THAR49 ARCO reserved word49. 597- 60006570004 CU THAR50 ARCO reserved word50. 601- 60406580004 CU THAR51 ARCO reserved word51. 605- 60806590004 CU THAR52 ARCO reserved word52. 609- 61206600004 CU THAR53 ARCO reserved word53. 613- 61606610004 CU THAR54 ARCO reserved word54. 617- 62006620004 CU THAR55 ARCO reserved word55. 621- 62406630004 CU THAR56 ARCO reserved word56. 625- 62806640004 CU THAR57 ARCO reserved word57. 629- 63206650004 CU EJECT 06660004 CU THAR58 ARCO reserved word58. 633- 63606670004 CU THAR59 ARCO reserved word59. 637- 64006680004 CU THAR60 ARCO reserved word60. 641- 64406690004 CU THAR61 ARCO reserved word61. 645- 64806700004 CU THAR62 ARCO reserved word62. 649- 65206710004 CU THAR63 ARCO reserved word63. 653- 65606720004 CU THAR64 ARCO reserved word64. 657- 66006730004 CU THMAV Absolute average amplitude of trace. fl pt r4 661- 66406740004 CU THBGRV Bouger gravity measurement *665- 66606750004 CU THRGRV Residual gravity *667- 66806760004 CU THTMAG Magnetic intensity measurement *669- 67006750004 CU THRMAG Filtered intensity measurement *671- 67206760004 CU THDMDZ Depth migration depth step (feet or meters). fl r4 673- 67606770004 CU THEREF Elevation of the refractor. 677- 68006780004 CU THVRLD VSP receiver depth (ft). 681- 68406790004 CU THVLDR VSP log depth reference (ft). 685- 68806800004 CU THVTVD VSP receiver tvd depth (ft). 689- 69206810004 CU THVKBE VSP kb elevation (ft). 693- 69606820004 CU THVWHE VSP ground elevation (ft). 697- 70006830004 CU THVPVT VSP p vertical time (microsec). 701- 70406840004 CU THVPMT VSP p measured time (microsec). 705- 70806850004 CU THVSVT VSP s vertical time (microsec). 709- 71206860004 CU THVSMT VSP s measured time (microsec). 713- 71606870004 CU THVBIA VSP borehole inclination (degrees). fl pt r4 717- 72006880004 CU THVBDA VSP borehole declenation (degrees). fl pt r4 721- 72406890004 CU THVOTI VSP original trace inclination (degrees). fl pt r4 725- 72806900004 CU THVOTA VSP original trace azimuth (degrees). fl pt r4 729- 73206910004 CU THVRTI VSP rotated trace inclination (degrees). ft pt r4 733- 73606920004 CU THVRTA VSP rotated trace azimuth (degrees). fl pt r4 737- 74006930004 CU THWGID WATR Western identification number. 741- 74406940004 CU THWGNM WATR Western wavename (alphanumeric). 745- 74806950004 CU THWVST WATR wavelet start time (ms). 749- 75206960004 CU THWVET WATR wavelet end time (ms). 753- 75606970004 CU THWVRT WATR first sample time (ms). 757- 76006980004 CU half-words are marked * 06990004 CU double-words are marked + 07000004 CU 07010004 CU Note 1 : Five halfword values used by GM3D were converted from 07020004 CU halfword to fullword values in May, 1985. The halfword 07030004 CU values will be used if the dataset was created prior 07040004 CU to this date. 07050004 CUEND 07060004 CU ARC-Y Format, Trace Header Indexing Formulas 07070004 CU 07080004 CU 1. Creation of trace header. 07090004 CU 07100004 CU A. Known. 07110004 CU THL = number of words in header. 07120004 CU THNS = number of words in trace = number of sample values. 07130004 CU 07140004 CU B. Calculated. 07150004 CU THFLV = IL = set by muting programs. 07160004 CU IN = THL + THNS = index of last trace value. 07170004 CU 07180004 CU 2. Use of trace header by control program. 07190004 CU The control program uses THL to supply the trace header and the 07200004 CU trace to a processing program in separate arrays. 07210004 CU 07220004 CU 3. Use of trace header by a processing program. 07230004 CU The processing program will obtain THFLV and THNS from the header.07240004 CU The trace will be in an array whose fortran indices are 07250004 CU 07260004 CU 1, 2, 3, ... THFLV, ... THNS. 07270004 CU 07280004 CU 07290004 CU 07300004 CU 07310004 CU Byte-Halfword-Fullword Relations 07320004 CU 07330004 CU B = byte number 07340004 CU H = halfword number 07350004 CU F = fullword number 07360004 CU 07370004 CU 07380004 CU B = 2H - 1 = 4F - 3 07390004 CU 07400004 CU 07410004 CU B + 1 07420004 CU H = ----- = 2F - 1 07430004 CU 2 07440004 CU 07450004 CU 07460004 CU B + 3 H + 1 07470004 CU F = ----- = ----- 07480004 CU 4 2 07490004 CUEND 07500004 CU ARC-Y Format, General Description 07510004 CU 07520004 CU The ARC-Y data set format contains four kinds of data blocks 07530004 CU (IBM "physical records"): 07540004 CU 07550004 CU 1. The SEG-Y line header, first block, 40 card images. 07560004 CU 07570004 CU 2. The processing history, recorded as card images in blocks 07580004 CU of 3200 bytes (40 card images). The history is recorded 07590004 CU job by job in chronological order. The last block is 07600004 CU padded with blanks. 07610004 CU 07620004 CU 3. The SEG-Y line header, second block, 400 bytes binary. 07630004 CU 07640004 CU 4. Traces. Each trace data block consists of a 760-byte 07650004 CU trace header (190 words) followed by the trace sample 07660004 CU values in IBM S/370 floating-point format (single pre- 07670004 CU cision, one full word). The programs are coded to accept 07680004 CU a trace of any length up to 8000 samples. 07690004 CU (NOTE: old ARC-Y data sets had trace header lengths of 38407700004 CU bytes or 96 words.) 07710004 CU 07720004 CU All trace output from the SPARC system is in ARC-Y format. 07730004 CU 07740004 CU If output to tape takes more than one reel, the line headers07750004 CU (items 1 and 3) are not repeated at the start of each reel. This07760004 CU is a departure from SEG-Y specifications. 07770004 CU The history (item 2) is likewise not repeated. 07780004 CUEND 07790004 CU ARC-Y Format, Line Header--First Data Block--Cards 07800004 CU 07810004 CU Identical to SEG-Y format except for ARCO additons on card image 07820004 CU numbers described below. Length = 3200, bytes = 800 words, 40 07830004 CU EBCDIC card images, 80 bytes per card, free form coding, and left 07840004 CU justified. 07850004 CU Card image numbers 31-35 used for field recording comments. 07860004 CU Card image number 38 used for area and line name continuations. 07870004 CU Card image number 39 used for dsn # and spool member #. 07880004 CU 07890004 CU 07900004 CU C 1 client company crew no. 07910004 CU C 2 line area map id 07920004 CU C 3 reel no day-start of reel year observer 07930004 CU C 4 instrument: mfg model serial no. 07940004 CU C 5 data traces/record auxiliary traces/record cdp fold 07950004 CU C 6 sample internal ms samples/trace bits/in bytes/sample 07960004 CU C 7 recording format format this reel measurement system 07970004 CU C 8 sample code: floating pt fixed pt fixed pt-gain correlated 07980004 CU C 9 gain type: fixed binary floating point other 07990004 CU C10 filters: alias hz notch hz band hz slope 08000004 CU C11 source: type number/point point interval 08010004 CU C12 pattern: length width 08020004 CU C13 sweep: start hz end hz length ms channel no type 08030004 CU C14 taper: start length ms end length ms type 08040004 CU C15 spread: offset max distance group interval 08050004 CU C16 geophones: per group spacing frequency mfg model 08060004 CU C17 pattern: length width 08070004 CU C18 traces sorted by: record cdp other 08080004 CU C19 map projection zone id coordinate units 08090004 CU C21 beginning shotpoint (observer's id): 08100004 CU C22 ending shotpoint (observer's id): 08110004 CU C23 direction of line: 08120004 CU C24 county state survey no. 08130004 CU C25 (not assigned.) 08140004 CU C26 (not assigned.) 08150004 CU C27 (not assigned.) 08160004 CU C28 (not assigned.) 08170004 CU C29 (not assigned.) 08180004 CU C30 (not assigned.) 08190004 CU C31 (field recording comments.) 08200004 CU C32 (field recording comments.) 08210004 CU C33 (field recording comments.) 08220004 CU C34 (field recording comments.) 08230004 CU C35 (field recording comments.) 08240004 CU C36 (not assigned.) 08250004 CU C37 (not assigned.) 08260004 CU C38 line(cont) area(cont) 08270004 CU C39 dsn# = spm = 08280004 CU C40 end ebcdic 08290004 CU EJECT 08300004 CU 'HEAD' cards may be used to supply this information to the SPARC 08310004 CU system in the form used by the plotting programs. 08320004 CU 'HEAD' card coding sheets are available. 08330004 CU 08340004 CU A more detailed description of these fields may be found in the 08350004 CU TASEIS section of the GEOPLOT manual under the section HEAD. A 08360004 CU current version of this documentation is also available online 08370004 CU from the SEIS menu under GEO. 08380004 CU 08390004 CUEND 08400004 CU ARC-Y Format, Processing History 08410004 CU 08420004 CU A history of the processing performed will be written after 08430004 CU the line headers on each SPARC output data set. The history will 08440004 CU be written job by job in chronological order. The processing 08450004 CU specifications for the previous jobs, if any, will be copied from 08460004 CU the input data set to the output data set. Then the specifications08470004 CU for the job being executed will be written on the output data set.08480004 CU 08490004 CU The processing specifications for each job will consist of 08500004 CU (1) a specially constructed processing specification card (PROC 08510004 CU card) and (2) part of the input data cards. 08520004 CU 08530004 CU The specially constructed PROC card will include all the pro-08540004 CU cesses performed in producing the output data set, but will not 08550004 CU show nodes and branches which may have led to other output data 08560004 CU sets. 08570004 CU 08580004 CU The input data cards included will be those used by the pro- 08590004 CU cesses specified on the specially constructed PROC card. 08600004 CU 08610004 CU The start and end of the specifications for each job will be 08620004 CU marked by special cards in the following format: 08630004 CU 08640004 CU cols. 1- 4 a code, '$JOB' for start of job, 08650004 CU '.JOB' for end of job, 08660004 CU '.MRK' for concatenated data sets, 08670004 CU '.END' after end of last job. 08680004 CU cols. 5- 6 sequence number on .MRK and .END cards. 08690004 CU cols. 7-14 the job name. 08700004 CU cols. 15-16 blank. 08710004 CU cols. 17-60 the data set name. DBG.Dxxxxxxx 08720004 CU cols. 61-62 blank. | | 08730004 CU cols. 63-70 the job time. | 28 08740004 CU cols. 71-72 blank. 22 08750004 CU cols. 73-80 the job date. 08760004 CU 08770004 CU The history will be written in data blocks of 3200 bytes (40 08780004 CU card images). The last block will be padded with blanks. 08790004 CU 08800004 CU If a job reads more than one data set, and therefore has more08810004 CU than one set of history records, the .END cards of all but the 08820004 CU last set of history records are changed to .MRK cards with 08830004 CU appropriate sequence numbers. The last set of history records has08840004 CU an .END card with an appropriate sequence number. This applies 08850004 CU only to history records read before the first output is written. 08860004 CUEND 08870004 CU ARC-Y Format, Line Header--Second Data Block--Binary 08880004 CU Identical to SEG-Y format. 08890004 CU Length = 400 bytes = 100 words. 08900004 CU 08910004 CU Fortran Byte08920004 CU Name Description No.08930004 CU 08940004 CU LHJBNO Job identification no. (project no.) 1 08950004 CU LHLNO Line no. (not used) 5 08960004 CU LHRLNO Reel no. 9 08970004 CU LHTPSP Number of traces per shot 13*08980004 CU LHATSP Number of aux. traces per shot 15*08990004 CU LHSI Sample interval-microseconds (for this data set) 17*09000004 CU LHORSI Original recorded sample interval (ms) 19*09010004 CU LHST Number of samples per trace (for this data set) 21*09020004 CU LHORST Original recorded samples per trace 23*09030004 CU LHDFCD Data sample format code 25*09040004 CU 1 = floating pt (4 bytes) 09050004 CU 2 = fixed pt (4 bytes) 09060004 CU 3 = fixed pt (2 bytes) 09070004 CU 4 = fixed pt w/gain code (4 bytes) 09080004 CU LHEXFD Expected fold per cdp 27*09090004 CU LHTSCD Trace sorting code 29*09100004 CU 1 = as recorded (no sorting) 09110004 CU 2 = cdp ensemble 09120004 CU 3 = single fold continuous profile 09130004 CU 4 = horizontally stacked 09140004 CU LHVSCD Vertical sum code (1 = no sum, 2 = 2 sum,...) 31*09150004 CU LHSWFS Sweep frequency at start 33*09160004 CU LHSWFE Sweep frequency at end 35*09170004 CU LHSWL Sweep length (ms) 37*09180004 CU LHSWCD Sweep code (1 = linear, 2 = parabolic, ...) 39*09190004 CU LHTSNO Trace number of sweep channel 41*09200004 CU LHSWTS Sweep trace taper length (ms) at start of trace 43*09210004 CU LHSWTE Sweep trace taper length (ms) at end of trace 45*09220004 CU LHSWTT Sweep taper type (1 = linear, 2 = (COS)**2, etc.) 47*09230004 CU LHTCF Correlated trace flag (1 = no, 2 = yes) 49*09240004 CU LHBGRF Binary gain recovery flag (1 = yes, 2 = no) 51*09250004 CU LHARCD Amplitude recovery method 53*09260004 CU 1 = none 09270004 CU 2 = spherical divergence 09280004 CU 3 = agc 09290004 CU 4 = other 09300004 CU LHMS Measurement system (1 = meters, 2 = feet) 55*09310004 CU LHSGPL Impulse signal polarity (1 = neg., 2 = pos.) 57*09320004 CU 09330004 CU Continued 09340004 CU EJECT 09350004 CU 09360004 CU LHVPCD Vibratory polarity code 59*09370004 CU not assigned. 61 09380004 CU . . 09390004 CU . . 09400004 CU . . 09410004 CU end of SEG-Y line header. 400 09420004 CU 09430004 CU ARCO additions. None at this time. Will follow byte 400. 09440004 CU 09450004 CU half-words are marked * 09460004 CUEND 09470004 CU SEG Exchange Tape Format, ARCO Specifications 09480004 CU The format version for SEG Exchange tapes used by Atlantic 09490004 CU Richfield conforms to that described in Geophysics, vol. 32, pages09500004 CU 1073-1081. The main features are described in the following 09510004 CU paragraphs with preferences for label lengths and other optional 09520004 CU items. 09530004 CU 09540004 CU The data are recorded on 9-track tape in a trace-sequential mode. 09550004 CU Each tape reel should be limited to a single line of data. Either09560004 CU 1200' or 2400' reels are acceptable, and an entire line should be 09570004 CU put on a single reel if at all possible. The first file on the 09580004 CU tape is the tape header record, which is written in EBCDIC. It is09590004 CU not standardized, but should contain information as to area and 09600004 CU line number, number of data files on the reel, number and type of 09610004 CU information traces in each shotpoint, and length and digitization 09620004 CU of the traces in milliseconds. 09630004 CU 09640004 CU The tape header file is followed by the data files, with each data09650004 CU file consisting of zero to eight information traces and 24 seismic09660004 CU traces and followed by an end-of-file mark. If the data is shot- 09670004 CU point ordered, each file is restricted to a single shotpoint with09680004 CU null traces added to fill out to a full 24-trace complement if 09690004 CU necessary. Each trace is written as a separate tape record in a 09700004 CU halfword integer format (16 bits per sample), two's complement for09710004 CU negative numbers, and has prefixed to it four 32-bit words which 09720004 CU make up the trace header. This header is written (with one 09730004 CU exception) in the following order: 09740004 CU 09750004 CU 09760004 CU WORD 1. 09770004 CU a file number beginning with 1 for the first data file. 09780004 CU 09790004 CU WORD 2. 09800004 CU trace number. (within each file) 09810004 CU (a) information traces. A number beginning with 1000, then09820004 CU 2000, 3000, and up to 8000, depending on the number09830004 CU present. 09840004 CU (b) seismic traces. A sequential number beginning with 1 09850004 CU and going to 24. 09860004 CU 09870004 CU WORD 3. 09880004 CU shotpoint identification number. 09890004 CU 09900004 CU WORD 4. 09910004 CU trace flag. 0 for dead trace, 1 for live trace. 09920004 CU 09930004 CU Continued 09940004 CU EJECT 09950004 CU 09960004 CU The last data file is followed by an additional end-of-file,09970004 CU giving a total of two following the last trace of the last file.09980004 CU No trailer records are written on the tape. 09990004 CU 10000004 CUEND 10010004 CU R4 Format 10020004 CU 10030004 CU There is no line header. 10040004 CU 10050004 CU The trace header is two words in EBCDIC code. 10060004 CU 10070004 CU 10080004 CU WORD 1. 10090004 CU shotpoint number. 10100004 CU 10110004 CU WORD 2. 10120004 CU trace number. 10130004 CU 10140004 CU 10150004 CU Trace values are S/370 floating point, single precision (Real*4). 10160004 CU 10170004 CUEND 10180004