P16N bathymetry: ASCII navigation and bathymetry data file was obtained from John Bullister at NOAA/PMEL (3/15/2000). The bathymetry data in this file were obtained from the ship's Marine Operations Abstract (MOA) logbook. Date, time, posiiton and SeaBeam center beam depth were manually entered into the MOA by the ship's officers at intervals of approximately every 30 minutes, with more frequent entries made when operations were under way. A sound speed of 1500m/sec was used in the Seabeam depth determination. A value of -9 is used for missing values. Compiled by: Frederick Menzia, NOAA-PMEL Expocode: 31DSCGC91_1 and 31DSCGC91_2 Chief Scientist: John Bullister Ship: R/V Discoverer Ports: Seattle, WA - Hilo, Hawaii - Seattle, WA Dates: 7 March 1991- 8 April 1991 "P16Nbathy.txt" is the original data, uncorrected depths, CGC format "P16Nbathy_edited.txt" is the edited data (see notes below), uncorrected depths, CGC format "P16N_bathy_gdc.dat" is the edited data, with uncorrected and corrected depths, GDC format Files updated 8/15/02 LDT ------------------------------------- Ascii format for the original data "P16Nbathy.txt" self-explanatory from the original data file headers. Format of the "GDC" format file, "P16N_bathy_gdc.dat" (one record per line): lat (ddddd.mmm) "S" negative lon (ddddd.mmm) "W" negative dpt (dddddd.d) meters imo (ii) month ida (ii) day iyr (ii) year ihr (ii) hour imi (ii) minute ise (ii) second ydat (yyyyddd.hhh) (Julian date in ytk format) ----------------------- Comments on data (J. Bullister and ) Bathymetric Data for P16N (CG-91-DI) NOAA Ship Discoverer Continuous SeaBeam data are not available for this expedition. The bathymetry data in this file were obtained from the ship's Marine Operations Abstract (MOA) logbook. Date, time, posiiton and SeaBeam center beam depth were manually entered into the MOA by the ship's officers at intervals of approximately every 30 minutes, with more frequent entries made when operations were under way. A sound speed of 1500m/sec was used in the Seabeam depth determination. A value of -9 is used for missing values. Compiled by: Frederick Menzia, NOAA-PMEL ---- 8-05-02 Data quality: differences between P16Nbathy.txt and P16Nbathy_edited.txt. In the original data file, the first 745 lines and header were duplicated exactly, so removed in both original and edited file. Line numbers below refer to this initially edited file. Overall: longitudes should be negative, not positive Problems with positions, looks like typos Made educated guesses on many, deleted others Date at midnight is incorrect in every case. line 8 should be 37 min longitude line 44: problem with long minutes - can't tell what it should be changed to 53 so it's spaced about 10 minutes from adjoining positions line 68: time is earlier than preceding line. On station, so just changed to 845 between preceding and following times line 76: longitude should be 134 based on adjoining points line 96: latitude is impossible - identical to previous point and ship is still moving. Delete line since there is no depth recorded here. line 130: latmin should be 59 line 154: latmin is impossible. Can't guess corect, change to 29.876 to fit others line 195: lonmin impossible. Change to 30.56 lines 208, 212: give speeds too large, but can't see easy solution line 310: time is wrong by one hour, should be 1654; latmin should be 59 line 333: latmin impossible, delete line line 400,401: longitude should be 134 not 135 lines 411,412,413: speeds look suspicious - probably times are entered wrong, but can't figure out how to correct line 424: longitude should be 135 line 545: lonmin wrong, delete line 550: not clear, but think the longmin should be 8 not 18 problem with positions around this line - get 30 kn speed, but can't see an obvious solution line 551: lonmin looks wrong, delete line 552: lonmin looks wrong, delete line 622: longitude deg don't make sense - try 56.177 - works ok line 643: latitude deg don't make sense - try 51.242 line 654: some problem here - speeds > 20, but can't see obvious problem probably just don't have time exactly right line 720: lat minutes should be 55.088 line 727: lon minutes should be 51.379 line 728: lat minutes should be 57.477 line 747: lat minutes should be 53.565 line 767: some problem here - large speeds, but don't see problem line 792: excessive speed, but don't see problem line 800: latmin and lonmin integers - not accurate enough, delete line line 827: latmin looks like it should be 21.947 line 844: lonmin looks like it should be 51.635 (guess) line 855: lower accuracy latmin and lonmin, and looks wrong, delete line line 937: lower accuracy latmin, lonmin, looks wrong, delete line line 938: lower accuracy latmin, lonmin, looks wrong, delete line line 969: integer latmin, looks wrong, delete line line 1023: londeg should be 58.837 line 1025: lower accuracy latmin, lonmin, looks wrong, delete line line 1198: latmin wrong, change to 25.942 line 1237: time too close to next, large speed - delete line line 1319: latmin looks wrong. Try 7.332 line 1345: latmin wrong. Delete line line 1460: latmin wrong. Delete line line 1506: latmin impossible. Try 22.994 (since 2 and 5 buttons next to each other) line 1554: lonmin impossible, change to 59.423 line 1562: latmin impossible, change to 0.338 line 1609: high speed, no bottom depth, so delete line line 1615: time is probably wrong - too close to next time for distance line 1679: latmin looks suspicious, delete line line 1698: latmin wrong, change to 48.78 line 1732: time too short, speed too high, delete line line 1809: latmin looks suspicious, delete line line 2130: latmin and lonmin impossible, delete line line 2140: lonmin wrong, delete line line 2198: latmin wrong, change to 48.326 line 2261: lonmin wrong, change to 35.497 total of 58 lines edited out for position (or possibly time) error line 49: date should be 17 line 106: date should be 18 line 213: date should be 20 line 327: date should be 22 line 387: date should 23 line 446: date should be 24 line 502: date should be 25 line 550: date should be 26 line 599: date should be 27 line 648: date should be 28 line 793: date should be 9 line 848: date should be 10 line 905: date should be 11 line 962: date should be 12 line 1016: date should be 13 line 1072: date should be 14 line 1128: date should be 15 line 1252: date should be 17 line 1311: date should be 18 line 1373: date should be 19 line 1475: date should be 21 line 1523: date should be 22 line 1580: date should be 23 line 1632: date should be 24 line 1739: date should be 26 line 1793: date should be 27 line 1847: date should be 28 line 1895: date should be 29 line 1996: date should be 31 line 2050: date and month should be 1 4 line 2148: date should be 3 line 2194: date should be 4 line 2234: date should be 5 line 2282: date should be 6