P24 bathymetry: Update 21 May 2003 ASCII navigation and bathymetry data files (9, 1 for each day) were obtained from from James Crease (UDel) 11/13/98. He had obtained the files from Miyake Takeharu of JHD. (See below.) The original data are apparently 1500 m/sec, uncorrected. Quality control: The bathymetric data are difficult to work with. They were recorded every 13 seconds. There is a large amount of noise, which is not apparently correlated with the times on station. We have therefore not produced a quality-controlled data file. We are using the Smith-Sandwell altimetric bathymetry product for the vertical sections. Expocode: 49RY9511_2 Chief Scientist: Masahiko Fujimura Ship: R/V Ryofu Maru Ports: Nagoya to Naha, Japan Dates: 1995.11.15 - 1995.11.30 "P24_bathy.zip" contains "dp951116.dat", etc which are the 9 original data files, JMA format (see below). "951115" refers to the date. One file per day. 13 second records. Depths are not corrected. No quality control applied. "P24_bathydist.dat" is the bathymetry file, projected onto straight lines between station positions, used for plotting the vertical sections. It is based on the Smith-Sandwell altimetric bathymetry. "P24_sta_bdep.dat" is the station list, with corrected bottom depths as corrected from the uncorrected depths in the p24su.txt file (WHPO station summary file) -------------------------- Ascii Navigation format for the original data "dp951116.dat", etc. date (yyyymmdd) time (hhmmss) latitude (dd-mm.mmmN) degrees and minutes, north longitude (ddd-mm.mmmE) degrees and minutes, east depth (dddddd) meters Format of the file used for section plotting "P24_bathydist.dat" ist (iii) station number (set to 1) dist (ffffff.f) distance (km) along section lat (dddddd.mm) decimal latitude lon (dddddd.mm) decimal longitude dpt (ddddd.d) depth meters Format of P24_sta_bdep.dat station (iiii) station number distance (xxxxx.x) km along section latitude (xxx.xxx) longitude (xxxx.xxx) pressure (xxxx.x) corrected depth in meters ----------------------------------------------------- Data quality - ----------------------------------------------------- Subject: Re: WOCE bathymetry on P24 Date: Fri, 13 Nov 1998 10:20:15 -0500 From: James Crease Organization: College of Marine studies To: miyake takeharu CC: Lynne Talley Miyake, many thanks for the data The information at the beginning of your e-mail had some strange characters in it but I think its fairly clear that the instrument was a 12khz machine,4 m below the surface, with depths calculated at an assumed soundspeed of 1500m/sec. There wasn't a format description but I interpret the time as local time (UTC+10),and the last 5 columns as depth in whole numbers of metres. The 6th column from the end occasionally has a 9 in it but otherwise is zero.Do you know what this is? Finally, should we add 4m to the depth to allow for the transducer depth or has that already been done? I assume that no sound speed correction (Carters tables have been applied. Thanks again miyake takeharu wrote: > > Dear Mr. Crease. > > You already knew by Yutaka's E-mail,we had received the bathymetric data > from JMA. > I send the data with this E-mail. > Sorry but, quality control is not doing these data. > > WOCE P24 LINE > Institute :Japan Meteorological Agency > Ship name : ryofu maru > Call sign :JHIL > > Period :1995/11/16 to 1995/11/24 > Company :NEC > Transmit frequency: 12 kHz > Sound velocity: 1500 m/sec > Location : 4 m under sea surface > > With regards, > > Takeharu MIyake > > > ****************************************************** > Takeharu MIYAKE > Japan Oceanographic Data Center, > Hydrographic Department, Maritime Safety Agency > address : Tsukiji 5-3-1 Chuo-ku Tokyo 104-0045 JAPAN > phone : +81-3-3541-3818 FAX : +81-3-3545-2885 > email : miyake@cue.jhd.go.jp > ****************************************************** > ------------------------------------------------------------------------ > Name: dep_24.ZIP > dep_24.ZIP Type: Zip Compressed Data (application/x-zip-compressed) > Encoding: base64