THE HYDROGRAPHIC SURVEYS DATA EXCHANGE FORMAT - "HYD93"
(Bathymetric Soundings and Hydrographic Features)
NATIONAL GEOPHYSICAL DATA CENTER
NATIONAL ENVIRONMENTAL SATELLITE, DATA, AND INFORMATION SERVICE
NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION
U.S. DEPARTMENT OF COMMERCE
COMPILED BY THE HYD93 TASK GROUP
Dan R. Metzger
LT Todd H. Berggren
LCOR Maureen Kenney
LT Tom Niichel
National Geophysical Data Center
Boulder, Colorado
December 1993
August 1998 - Revised by Dan Metzger
(made Y2K compliant)
October 2000 - Revised by Dan Metzger
(Binary HYD93 records added)
INTRODUCTION I
GENERAL DESCRIPTION II
THE HEADER RECORD III
THE DATA RECORD IV
THE DATA RECORD (Binary HYD93) V
CARTOGRAPHIC CODES APPENDIX A
HORIZONTAL DATUM CODES APPENDIX B
VERTICAL DATUM CODES APPENDIX C
NGDC CONTACTS APPENDIX D
I. INTRODUCTION
During 1993 the National Geophysical Data Center decided to
integrate it's collection of National Ocean Service hydrographic
survey data into the already existing GEODAS (GEOphysical
DAta System) data managment system. In doing this NGDC created
an exchange format for disseminating this data. As can be
seen below, the HYD93 format was patterned after the ever popular
MGD77 exchange format. This allowed relatively easy assimilation
of the data into the GEODAS system, and a standardized software
interface for the user.
II. GENERAL DESCRIPTION
The digital format presented, and referred to as
"HYD93", is an exchange format for hydrographic survey data
(bathymetry soundings and hydrographic features) It is intended
to be used for the transmission of data to and from a data center
and may be useful for the exchange of data between marine
institutions. Data is to be exchanged in files, two files per
survey operation (see below) or in the manner of organizing the data
at the contributing institution. Data may be exchanged on magnetic
tape or on various mass storage devices such as tape or disks, or
over the Internet. The National Geophysical Data Center uses CD-ROM
disks as its chief method of distribution of these
data.
The HYD93 format was developed as an ASCII format for both the Header
Record and the Data Records, but the Data Records can also be in
binary form, called Binary HYD93. This format is a space-saving subset
of the data which may have some appeal for users. Binary HYD93 is the
format which is used to store the survey files on NGDC's hydrographic
survey CD-ROMs.
A. Data Exchange
1. For exchange purposes each digital HYD93 survey shall consist
of a file containing the HYD93 Header (survey documentation) and a
file of HYD93 data records (soundings and features). If the media is
too small to contain all the data records a second data record file
may be continued on a second media.
2. A wide range of distribution methods are available. Densities,
blocking, byte order, and computer formats must be explicitly
detailed.
a. FTP (file transfer protocol) in ASCII or compressed form.
b. Magnetic 8mm tape in UNIX tar format or ASCII format.
c. Mass storage files on media such as floppy disks,
CD-ROM Write-Once media , removable magnetic/optical
disks, etc.
III. THE HEADER RECORD
The purpose of the Header Record is to document both
the content and structure of the hydrographic data contained
within the data records. In general, documentation that is
constant throughout the survey will be in the Header Record,
while documentation that is variable will be in the Data ReCords.
On mass storage media, the HYD93 Header consists of a file
of 24 80-character sequential records. For magnetic tapes the
HYD93 Header is a file of one physical record (block) consisting
of 1,920 characters.
The Header Record contains fields which are both fixed
and freely formatted. All field lengths within the Header
that have not been coded with information should be blank-
filled, and all plain language statements should be left-
justified. The Header consists of a "sequence" of twenty-
four 80-character images.
Format Conventions for the Header Record:
1. All decimal points are explicit characters in the Header
2. Leading zeros and blanks are equivalent.
3. Unknown or unused fields are to be blank filled.
The following is a detailed description of the Header Record.
Fields can be of type integer, real or character. Fields that
represent whole numbers are integers Fields that contain a
decimal component are real, and fields that are alphanumeric
are character.
Length
Character of
Nos. Field Type Description
_____________________________________________________
Sequence No. 1
1 1 integer RECORD TYPE - ("4")
2-9 8 char SURVEY IDENTIFIER
identifier supplied by the contributing
organization, else given by NGDC in
a manner which represents the data.
Identical to that in data record.
10-14 5 char FORMAT ACRONYM - ("HYD93")
15-22 8 integer DATA CENTER FILE NUMBER
survey identifier bestowed by the data
center. First 2 chars indicate the
source, first 4 indicate platform.
27-31 5 char PARAMETERS SURVEYED CODE
if codepresent, parameter is contained in
file.
COL CODE PARAMETER SURVEYED
1 S bathymetry soundings
2 F hydrographic features
32-39 8 integer FILE CREATION DATE (YYYYMMDD)
date data records were
last altered.
40-78 39 char SOURCE INSTITUTION
organization which collected
the data. Include contributor
if different from collector.
79-80 2 integer SEQUENCE NUMBER - ("01")
Sequence No. 2
1-18 18 char COUNTRY
19-39 21 char PLATFORM NAME
40 1 integer PLATFORM TYPE CODE
0 - Unspecified
1 - Surface ship
2 - Submersible ship
3 - Aircraft
4 - Buoy
5 - Mobile land
6 - Fixed land
7 - Deep tow
8 - Anchored seafloor
9 - Other, specify
41-46 6 char PLATFORM TYPE
(e.g. "SHIP", "PLANE",
"SUB", etc.)
47-78 32 char CHIEF HYDROGRAPHER(S)
79-80 2 integer SEQUENCE NUMBER - ("02")
Sequence No. 3
1-29 29 char PROJECT
(e.g. "OPR-K220-WH" or
"Norton Sound Hydro Survey")
30-58 29 char TYPE OF SURVEY
(e.g. "Basic Hydrographic Survey"
or "Wire-drag field examination")
59-62 4 integer START YEAR OF SURVEY WORK
63-66 4 integer END YEAR OF SURVEY WORK
67-78 12 char SCALE OF SURVEY
if number is not a ratio,
assume ratio of 1:number.
(e.g. "1:20,000" or "250,000")
79-80 2 integer SEQUENCE NUMBER - ("03")
Sequence No. 4
1-26 26 char AREA (GENERAL) OF SURVEY
(e.g. "Gulf of Mexico")
27-78 52 char AREA (SPECIFIC) OF SURVEY
(e.g. "Texas Continental
Shelf")
79-80 2 integer SEQUENCE NUMBER - ("04")
Sequence No. 5
1-42 42 char QUALITY OF SURVEY DESCRIPTION
(e.g. "Adequate, complete")
43-78 36 char PROCESSING STATUS DESCRIPTION
(e.g. "Evaluated, inspected,
approved")
79-80 2 integer SEQUENCE NUMBER - ("05")
Sequence No. 6
1-78 78 char POSITION DETERMINATION
method of determining
horizonta position.
(e.g. NAVSTAR GPS System)
79-80 2 integer SEQUENCE NUMBER - ("06")
Sequence No. 7
1-5 5 char HORIZONTAL DATUM CODE (RECORDS)
(e.g. "NOS31") see Appendix B.
6-39 34 char HORIZONTAL DATUM OF RECORDS
the horizontal datum of the records.
(e.g. North American Datum 1983)
40-44 5 char HORIZONTAL DATUM CODE (ORIGINAL)
(e.g., "NOS06") see Appendix B.
45-78 34 char ORIGINAL HORIZONTAL DATUM
the horizontal datum originally used.
(e.g. North American Datum 1927)
79-80 2 integer SEQUENCE NUMBER - ("07")
Sequence No. 8
1-2 2 integer VERTICAL DATUM CODE
(e.g. "04") see Appendix C.
3-53 51 char VERTICAL DATUM
(e.g. "Mean Lower Low Water")
54-57 4 real AVERAGE TIDE RANGE
in meters for survey
area. (e.g. "5.30")
58-78 21 integer ORIGINAL SOUNDING UNITS
(e.g. fathoms and feet)
79-80 2 integer SEQUENCE NUMBER - ("08")
Sequence No. 9
1-78 78 char SOUNDING METHOD
(e.g. Digital Echo Sounder)
79-80 2 integer SEQUENCE NUMBER - ("09")
Sequence No. 10
1 1 integer SOUND VELOCITY CORRECTION CODE
0 - Undetermined
1 - Corrected
2 - Uncorrected, 1463 meters/sec
3 - Uncorrected, 1500 meters/sec
4 - Uncorrected, unknown vel.
2-78 77 char SOUND VELOCITY CORRECTION
(e.g. Corrected, Carter's Tables)
79-80 2 integer SEQUENCE NUMBER - ("10")
Sequence No. 11
1-78 78 char DATA PROCESSING METHODOLOGY
(e.g. digitized smooth sheets)
79-80 2 integer SEQUENCE NUMBER - ("11")
Sequence No. 12
1-52 52 char FORMAT OF DATA RECORDS
set to:
SURV,LAT,LON,VAL,TYP,CCODE
(A8,F9.6,F10.6,F6.1,I1,I3)
53-58 6 real TOP-MOST LATITUDE OF SURVEY
to hundredth of degree
(e.g. +29.50)
59-64 6 real BOTTOM-MOST LATITUDE OF SURVEY
to hundredth of degree
(e.g. +28.33)
65-71 7 real LEFT-MOST LONGITUDE OF SURVEY
to hundredth of degree
(e.g. -101.67)
72-78 7 real RIGHT-MOST LONGITUDE OF SURVEY
to hundredth of degree
(e.g. -099.50)
79-80 2 integer SEQUENCE NUMBER - ("12")
Sequence Nos. 13-24
1-78 78 char ADDITIONAL DOCUMENTATION
other information concerning
this survey.
79-80 2 integer SEQUENCE NUMBER
("13" through "24")
________________________________________________________
IV. THE DATA RECORD
Each data record presents a bathymetric sounding value or
hydrographic feature value with corresponding position, value
type, and cartographic code.
Format Conventions:
1. All decimal points are implied (e.g. 1234 in 10ths of units means 123.4)
2. Leading zeros and blanks are equivalent.
3. Unknown or unused values are filled with 9's.
4. All Bathymetric Sounding (non-feature) data records include
a known depth value, a value type of 0 (actual depth) and a
cartographic code of 711 (Sounding in meters and tenths).
5. Negative depth values indicate elevations.
6. Hydrograpic Feature records with non-zero Value Type may
or may not have a known (non 9's) value.
7. Hydrographic Feature which are "Line Features" do not include
depths. Instead the depth value fields are used for the sequence
numbers each record along the line feature (1...n).
The following is a detailed description of the Data Record.
Fields can be of type integer, real or character. Fields that represent
whole numbers are integers Fields that contain a decimal component are
real (the decimal point is always implied), and fields that are alphanumeric
are character.
Length
Character of
Nos. Field Type Description
____________________________________________________________
1-8 8 char SURVEY IDENTIFIER
identifier supplied by the contributing
organization, else given by NGDC in
a manner which represents the data.
Identical to that in header record.
9-17 9 integer LATITUDE X 1,000,000
+=North; -=South
i.e. 1234567 = +1.234567 degrees
18-27 10 integer LONGITUDE X 1,000,000
+=East; -=West
i.e. -123456789 = -123.456789 degrees
28-33 6 integer DEPTH VALUE x 10 IN METERS
(or Line Feature sequence number)
i.e. 1234 = 123.4 meters
34 1 integer VALUE TYPE CODE
defines depth type
0 - Known depth (or elevation)
1 - Submerged (below water level)
2 - Awash (about water level)
3 - Visible (above water level)
35-37 3 integer CARTOGRAPHIC CODE
3 character code
describing the type of record, as
defined by the National Ocean Service.
see Appendix A.
IV. THE DATA RECORD (Binary HYD93)
HYD93 Binary Format is a binary representation of the HYD93 data record.
It is the format in which files are stored on NGDC's hydrographic
survey CD-ROM sets. The fields included in this format are binary
representations of some of the fields in the HYD93 ASCII data record.
Each data record presents a bathymetric sounding value or hydrographic
feature value with corresponding position, value type, and cartographic
code. The survey id, which occurs in the ASCII HYD93 data record, is
absent in HYD93 Binary Records
Format Conventions for the Binary Data Record:
1. Unknown or unused fields have a value of 9's:
unknown depth = 999999
unknown type/carto-code = 9999
2. All Bathymetric Sounding (non-feature) data records include
a known depth value, a value type of 0 (actual depth) and a
cartographic code of 711 (Sounding in meters and tenths).
3. Negative depth values indicate elevations.
4. Hydrograpic Feature records with non-zero Type may
or may not have a known (non 9's) value.
5. Hydrographic Feature which are "Line Features" do not include
depths. Instead the depth value fields are used for the sequence
numbers each record along the line feature (1...n).
Field Name Number Type Description
____________________________________________________________
LATITUDE X 1,000,000 4 Byte Integer Latitude in millionths of degrees
+=North; -=South
LONGITUDE X 1,000,000 4 Byte Integer Longitude in millionths of degrees
+=East; -=West
DEPTH VALUE X 10 4 Byte Integer Depth in tenths of meters
(or Line Feature sequence number)
TYPE/CARTO CODE 2 Byte Integer type-code * 1000 + carto-code*
*type/carto code combines the type code field with the carto code field by
multiplying the type times 1000 and adding the carto code. e.g. a type code
of 3 and a carto-code of 123 computes to a TYPE/CARTO CODE value of 3124.
____________________________________________________________
APPENDIX A CARTOGRAPHIC CODES
002 Shoal/Shallow (area limits)
009 Reef or Ledge, submerged (area limits)
010 Dolphin (visible)
011 Breakers (area limits)
014 Marsh (area limits)
016 Pier, floating
017 Lava (area limits)
025 Levee, Dike (double line)
026 Breakwater, jetty (submerged)
027 Breakwater/Jetty
029 Breakwater, jetty (area limits)
030 Pier
031 Groin
038 Wharf, bulkhead, seawall, etc
039 Marine Railway
040 Drydock
041 Floating Drydock
042 Marine Railway (subm. offshore limits)
043 Lock
044 Wreck, hulk (visible, to scale)
055 Ramp
056 Well, oil or gas (submerged)
057 Bridge (configuration)
058 Canal (double line)
059 Bridge (symbol, single line)
060 Danger (submerged, area limits)
065 Dam
085 Obstruction (visible)
089 Rock or coral head (submerged or awash)
090 Wreck (Wire drag clearence)
091 Rock (wire drag clearance)
092 Obstruction (wire drag clearance
094 Rock (no elevation)
095 Coral (wire drag clearance)
097 Islet (symbol)
098 Wreck (visible)
099 Wreck, masts visible
100 Wreck (submerged)
101 Sounding on wreck (whole feet)
103 Kelp
104 Rock (no depth)
105 Pipe (visible)
106 Stake (visible)
107 Ruins (submerged, area limits)
108 Crib (submerged, area limits)
109 Crib (visible, area limits)
110 Pile (visible)
111 Platform - oil or gas
112 Sand waves (line feature)
121 Fish trap
124 Buoy, vertically striped, lighted
139 Lighthouse
146 Tide rips (label)
147 Pipeline, oil or haz. material (subm.)
165 Rock or Coral Head (visible)
182 Buoy, horizontal banded, lighted
200 Structure, lighted (including lighthouses)
208 Light, front range
209 Light, rear range
211 Buoy, diagonally banded, lighted
212 Buoy, open (symbol)
214 Buoy, vertical striped
215 Buoy, mooring
216 Buoy, horizontal banded
217 Buoy, diagonally banded
218 Buoy, checkered
219 Daybeacon, black
223 Daybeacon, open
224 Daybeacon, red
228 Groin (submerged)
229 Marker, private (lighted)
230 Stump
231 Snag (visible)
232 Deadhead
233 Dolphin (submerged)
234 Pile (submerged)
235 Pipe (submerged)
236 Stake (submerged)
237 Stump (submerged)
238 Snag (submerged)
239 Shoal (wire drag clearance)
241 Crib (symbol)
243 Hydrographic Station
248 Platform (survey)
249 Platform (oil or gas) lighted
255 Buoy, red
256 Buoy, black
257 Buoy, red, lighted
258 Buoy, black, lighted
259 Buoy, Open symbol, lighted
260 Ruins (config. or area limits)
261 Marker (privately maintained)
278 Dolphin (awash)
279 Pile (awash)
280 Pipe (awash)
281 Stake (awash)
282 Stump (awash)
283 Snag (awash)
284 Obstruction (awash)
285 Ruins (awash, area limits)
286 Crib (awash, symbol)
287 Obstruction (submerged)
290 Sounding, on rock, whole feet
291 Rock with elevation
438 Fish trap perimiter (area limits)
472 Buoy, checkered, lighted
477 Wreckage (area limits)
480 Anchorage (large vessels)
481 Buoy, green
482 Buoy, green, lighted
498 Buoy, mooring, lighted
530 Ledge or Reef (line feature)
535 Rapids, label only
536 Eddies
537 Shoal (label)
538 Foul (label)
539 Breakers (label)
548 Rocky
550 Bottom Sample
562 Coralhead
568 Boulders
591 Oysters
593 Sponge
594 Seaweed
599 Kelp (Label only)
702 Anchorage (small vessels)
711 SOUNDING (METERS AND TENTHS)
767 Daybeacon, green
787 Buoy, superbuoy, lighted
801 Pipeline, sewer outfall
802 Ramp (to scale)
803 Pipeline, potable water intake
865 Levee, dike
869 Living resources, oyster bed/bar (line feature)
871 Kelp (line feature)
872 Grass (line feature)
877 Glacier (area limits)
883 Piles (visible, row or config)
884 Ruins (visible, symbol)
885 Duck blind (visible)
886 Duck blind ruins (visible)
889 Oil, gas well (visible)
890 Crib (submerged, symbol)
891 Ruins (submerged, symbol)
892 Crib (awash, area limits)
893 Ruins (awash, symbol)
894 Foul (area limits)
906 Daybeacon, front range
907 Daybeacon, rear range
923 Piles (submerged, row or config)
925 Piles (awash, row or config)
926 Piles (visible, area limits)
927 Piles (submerged, area limits)
930 Piles (awash, area limits)
947 Articulated light
957 Rock - Side scan sonar depth
961 Wreck - Side scan sonar depth
967 Obstruction - Side scan sonar depth
988 Islet
____________________________________________________________
APPENDIX B HORIZONTAL DATUM CODES
NATIONAL OCEAN SERVICE CODES
NOS01 - Bessel Spheroid 1841-80
NOS02 - Clarke Spheroid of 1866
NOS03 - Astronomic Datum (General)
NOS04 - United States Standard Datum 1901
NOS05 - North American Datum 1913
NOS06 - North American Datum 1927
NOS07 - Old Hawaiian Datum
NOS08 - Kauai Datum
NOS09 - Lisanski 1931 (Field)
NOS10 - Laysan 1930 (Field)
NOS11 - Gardners Pinnacles 1929 (Field)
NOS12 - French Frigate Shoal 1928 (Field)
NOS13 - Necker 1928 Datum
NOS14 - Nihoa 1928 Datum
NOS15 - Vigan Datum
NOS16 - Luzon Datum 1911
NOS17 - San Juan Astro Datum 1901
NOS18 - Puerto Rico Datum
NOS19 - Limon Bay - Colon 1877
NOS20 - Panama Harbor Panama Cathedrl 1877
NOS21 - Panama - Colon Datum 1911
NOS22 - Valdez Datum
NOS23 - Unalaska Datum
NOS24 - Southeast Alaska Datum
NOS25 - Aleutian Islands Datum
NOS26 - Nushagak Bay Datum
NOS27 - Cape Newenham Datum
NOS28 - Norton Sound Datum
NOS29 - Port Clarence and Pribilof Islands
NOS30 - North American Datum of 1902
NOS31 - North American Datum of 1983
NOS32 - Guam 1963 Datum
NOS33 - World Geodetic System (WGS) 1972
NOS34 - World Geodetic System (WGS) 1984
NOS35 - Johnston Island 1961 Astro Datum
NOS36 - Maro Reef Astro Datum 1930 (Field)
NOS37 - Bosun Astronomic Datum 1941 Field
NOS38 - Preliminary North American 1927
NOS39 - Palmyra Atoll - Astro Datum 1944
MGGHA - Early Hawaiian Island Datums
MGGPR - Early Puerto Rico Island Datums
MGGSL - Early St. Laurence Island Datums
MGGSG - Early St. George Island Datums
MGGSP - Early St. Paul Island Datums
MGGAL - Early Alaska Datums
NOSXX - Undetermined Datum
____________________________________________________________
APPENDIX C VERTICAL DATUM CODES
00 - Undetermined vertical datum
01 - Mean Sea Level
02 - Mean Low Water
03 - Mean Low Water Springs
04 - Mean Lower Low Water
05 - Mean Lower Water Springs
06 - Lowest Normal Low Water
07 - Lowest Low Water
08 - Indian Spring Low Water
09 - Great Lakes Low Water
10 - Low Lake Level - Lake Champlain
11 - Normal Pool Level - Cayuga & Seneca Lakes
12 - Hudson River Datum
13 - Normal Lake Level - Franklin D. Roosevelt Lake
14 - Sacramento River - Sacramento to Old Ferry
15 - Columbia River Datum
16 - Local Low Water
17 - Gulf Coast Low Water
18 - Low Water Datum 600.0 ft IGLD-1955 Lake Superior
19 - Low Water Datum 576.8 ft IGLD-1955 L Michigan,Huron
20 - Low Water Datum 571.7 ft IGLD-1955 Lake St. Clair
21 - Low Water Datum 568.6 ft IGLD-1955 Lake Erie
22 - Low Water Datum 242.8 ft IGLD-1955 Lake Ontario
23 - Mystic River Datum
24 - Mean High Water
25 - Low Water Datum 601.1 ft IGLD-1985 Lake Superior
26 - Low Water Datum 577.5 ft IGLD-1985 L Michigan,Huron
27 - Low Water Datum 572.3 ft IGLD-1985 Lake St. Clair
28 - Low Water Datum 569.2 ft IGLD-1985 Lake Erie
29 - Low Water Datum 243.3 ft IGLD-1985 Lake Ontario
____________________________________________________________
APPENDIX D NGDC CONTACTS
Dan R. Metzger: (303) 497-6542 Dan.R.Metzger@noaa.gov
or
John G. Campagnoli : (303) 497-3158 John.G.Campagnoli@noaa.gov
National Geophysical Data Center
NOAA, E/GC3
325 Broadway
Boulder, CO 80303-3328
TELEX 592811 NOAA MASC BDR
FAX (303) 497-6513
____________________________________________________________