最初の４レコードはヘッダー情報が入っている。
Header record No.1
Character Code Description
1 I1 Record Type "1"
2 I1 "1" for No.1 record
3-10 8A1 Cruise identifer (eg. GH91-A )
11-12 I2 Survey Departure Year (eg.91)
13-15 I3 Survey Departure Day (Julian Day, eg. 171)
16-43 28A1 Port of Departure(eg. FUNABASHI, JAPAN )
44-45 I2 Survey Arrival Year (eg.91)
46-48 I3 Survey Arrival Day (Julian Day, eg. 186)
49-76 28A1 Port of Arrival(eg. SAKATA, JAPAN )
77-80 4A1 Available Data Identifer
"NBMG", when navigational, bathymetric,
magnetic and gravity data are in the file.
Header record No.2
Character Code Description
1 I1 Record Type "1"
2 I1 "2" for No.2 record
3-40 38A1 Magnetic Reference Field, Geodesic System, Time
(e.g. IGRF85TOKYO GMT)
41-49 9A1 Gravity Reference Field (e.g. IAG1967)
50-57 8A1 Gravity Reference System (e.g. IGSN71)
58-59 I2 Year at Gravity Base Station
60-62 I3 Julian Day at Gravity Base Station
63-69 I7 Absolute Gravity Value at the Base Station
(×0.1mgal)
70-75 I6 Gravity Reading by the Sea Gravimeter at the Base Station(×0.1)
76-80 I5 Drift Rate of the Sea Gravimeter (×0.01/day)
Header record No.3 and No.4
Character Code Description
1 I1 Record Type "2"
2 I1 "1" for No.3 record, "2" for No.4 record
3 blank
4-5 I2 Number of 10 degrees Identifiers
6-80 15(I4,1H,) 10 degree Identifier ("9999", if no more data)
Data Record
Character Code Description
1 I1 Record Type "3"
2-3 I2 Year
4-6 I3 Julian Day
7-10 I4 Time (GMT in minutes)
11 A1 "N" Navigational data
12-19 I8 Latitude 4046046 = 40.46046 degree N
20-28 I9 Longitude 13958521 = 139.58521 degree E
29 A1 "V" Velocity data
30-33 I4 Ship's speed " 374" = 3.74 kt
34-37 I4 Ship's course "2234" = 223.4 deg crockwise from North
38 A1 "B" Bathymetric data
39-43 I5 Uncorrected Depth (m), 1sec 2-way travel time=750m
44-48 I5 Corrected Depth (m)
49-50 I2 Matthews Zone Code
51 A1 "M" magnetic data
52-56 I5 Total Magnetic Force (nT)
57-61 I5 Magnetic anomaly (nT)
62 A1 "G" gravity data
63-68 I6 Gravity Reading (×0.1)
69-75 I7 Absolute Gravity Value (×0.1mgal)
76-80 I5 Free-air Anomaly (×0.1mgal)
11GH91-A 91171FUNABASHI, JAPAN 91186SAKATA, JAPAN NBMG
12 IGRF85TOKYO GMT IAG1967 IGSN71 911719797894 42692 17
21 41313,1314,1414,1413,9999,9999,9999,9999,9999,9999,9999,9999,9999,9999,9999,
22 49999,9999,9999,9999,9999,9999,9999,9999,9999,9999,9999,9999,9999,9999,9999,
391171 240N99999999999999999V99999999B999999999999M9999999999G999999999999999999
391171 241N99999999999999999V99999999B999999999999M9999999999G999999999999999999
391173 423N 4046046 13958835V 3742234B 835 81778M48975 189G 475879802639 547
391173 424N 4045955 13958725V 4522228B 850 83278M48953 167G 475919802615 526
391173 425N 4045866 13958621V 4622211B 861 84278M48962 176G 475939802619 530
391173 426N 4045776 13958521V 4152207B 876 85778M48954 168G 475949802639 550