Hydrographic Surveys Data Exchange Format - HYD93
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/DVD
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/DVDs.
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/DVD 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.
*** CHANGES SINCE LAST VERSION ***
Several changes in the HYD93 Format were required in order to
make the format "Year 2000 Compliant" (Y2K Compliant):
SEQUENCE DESCRIPTOR CHANGE
______________________________________________-
01 RECORD TYPE Change from "1" to "4"
01 FILE CREATION DATE Change to include century
From 6 digits (col 32-37)
to 8 digits (col 32-39)
01 SOURCE INSTITUTION Change from 41 chars (col 38-78)
to 39 chars (col 40-78)
The following is a detailed description of the Header
Record.
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 6 real LEFT-MOST LONGITUDE OF SURVEY
to hundredth of degree
(e.g. -101.67)
72-78 6 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.
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.
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
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/DVD 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.
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
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
056 Oil or gas well
089 Rock or coral head (depth known or unknown)
090 Wire-drag clearence
098 Wreck
111 Platform - oil or gas
165 Rock or coral head (estimated depth)
232 Deadhead
248 Platform (survey)
249 Platform (oil or gas), lighted
278 Dolphin
279 Pile
280 Pipe
281 Stake
282 Stump
283 Snag
284 Obstruction
367 Sounding, labeled hard
711 SOUNDING (METERS AND TENTHS)
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
____________________________________________________________
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 80305-3328
TELEX 592811 NOAA MASC BDR
FAX (303) 497-6513
____________________________________________________________