Maptitude GISDK Help

Datum Conversions

For many datasets, a datum conversion can be specified to transform the dataset to a different datum. When importing, the transformation is applied after the inverse projection. When exporting, the transformation is applied prior to the projection.

 

The transformation is specified with the NAD Conversion option, which requires the source and destination datum, and sometimes a third parameter that indicates the conversion method or grid file.

 

For U.S. datasets, Maptitude uses NADCON, the federal standard, to convert between the North American 1927/Old Island (NAD27), North American 1983 (NAD83), and North American 1983 HPGN/HARN (NAD83HP) datums. If the conversion is either to or from NAD83HP, you must specify the HP conversion file; otherwise leave the third parameter null. The following table lists the currently available HP conversion files in the Datum folder:

 

File Name

Coverage

alhpgn

Alabama

arhpgn

Arkansas

azhpgn

Arizona

eshpgn

American Samoa (E of 170th Meridian)

wshpgn

American Samoa (W of 170th Meridian)

cnhpgn

California (N of 37th Parallel)

cshpgn

California (S of 37th Parallel)

cohpgn

Colorado

mdhpgn

Delaware, Maryland, District of Columbia

flhpgn

Florida

gahpgn

Georgia

guhpgn

Guam and Northern Marianas Islands

hihpgn

Hawaii

emhpgn

Idaho & Montana (E of 113rd Meridian)

wmhpgn

Idaho & Montana (W of 113rd Meridian)

ilhpgn

Illinois

inhpgn

Indiana

iahpgn

Iowa

kshpgn

Kansas

kyhpgn

Kentucky

lahpgn

Louisiana

mehpgn

Maine

mihpgn

Michigan (except Isle Royale)

mnhpgn

Minnesota

mshpgn

Mississippi

mohpgn

Missouri

nbhpgn

Nebraska

nvhpgn

Nevada

nehpgn

New England (except Maine)

njhpgn

New Jersey

nmhpgn

New Mexico

nyhpgn

New York

ndhpgn

North Dakota

ohhpgn

Ohio

okhpgn

Oklahoma

wohpgn

Oregon & Washington

pahpgn

Pennsylvania

pvhpgn

Puerto Rico & Virgin Islands

sdhpgn

South Dakota

tnhpgn

Tennessee

ethpgn

Texas (E of 100th Meridian)

wthpgn

Texas (W of 100th Meridian)

uthpgn

Utah

vahpgn

Virginia

wihpgn

Wisconsin

wvhpgn

West Virginia

wyhpgn

Wyoming

 

Here are some examples:

 

// Convert from NAD27 to NAD83

...

{"NAD Conversion", "NAD27", "NAD83",}

...

 

// Convert from NAD27 to NAD83HP for Maine

...

{"NAD Conversion", "NAD27", "NAD83HP", "datum\\mehpgn"}

...

 

For Canadian datasets, Maptitude uses NTv2, the Canadian standard, to convert between the North American 1927 datum (NAD27), the May 1976 Adjustment of NAD27 used in Ontario (MAY76), or the Average Terrestrial System of 1977 used in New Brunswick (ATS77), and the North American 1983 datum (NAD83).  Direct conversion is not supported between NAD27 and MAY76 or ATS77.  If the conversion is between NAD27 and NAD83, then the third parameter must be "NTv2" to distinguish it from the NADCON conversion.

 

For conversions in New Brunswick between ATS77 and NAD83, the NB7783v2.GSB grid shift file is required.  It is available for C$100 directly from Service New Brunswick (http://www.snb.ca/).  It needs to be installed in the Datum folder of the Maptitude program folder. Here are some examples:

 

// Convert from NAD27 to NAD83

...

{"NAD Conversion", "NAD27", "NAD83", "NTV2_0.GSB"}

...

 

// Convert from ATS77 to NAD83

...

{"NAD Conversion", "ATS77", "NAD83","NB7783v2.GSB"

...

 

For the following countries, Maptitude uses NTv2 to convert between the datums. The NAD Conversion option is specified as shown above, with the appropriate grid shift file as the third parameter. Here is a list:

For more details on these conversions, see "Datums" in the Maptitude Help.

 

For Austria, the conversion requires the AT_GIS_GRID.GSB grid shift file, available from the Bundesamt für Eich- und Vermessungswesen website: http://www.bev.gv.at.  It needs to be installed in the Datum folder in the Maptitude program folder.

 

For other datasets worldwide, cruder methods can be employed to convert between datums. Maptitude supports the standard 3-parameter, 7-parameter and Molodensky methods. The appropriate method is determined automatically based on the datum strings used, except when "Molodensky" is specified as the third parameter to override the 3-parameter default. The following table lists the currently available datums:

 

Datum Code

Coverage

WGS72

WORLD GEODETIC SYSTEM 1972

WGS84

WORLD GEODETIC SYSTEM 1984

ADI-A

ADINDAN, Ethiopia

ADI-B

ADINDAN, Sudan

ADI-C

ADINDAN, Mali

ADI-D

ADINDAN, Senegal

ADI-E

ADINDAN, Burkina Faso

ADI-F

ADINDAN, Cameroon

ADI-M

ADINDAN, Mean

AFG

AFGOOYE, Somalia

AIA

ANTIGUA ISLAND ASTRO 1943

AIN-A

AIN EL ABD 1970, Bahrain

AIN-B

AIN EL ABD 1970, Saudi Arabia

AMA

AMERICAN SAMOA 1962

ANO

ANNA 1 ASTRO 1965, Cocos Is.

ARF-A

ARC 1950, Botswana

ARF-B

ARC 1950, Lesotho

ARF-C

ARC 1950, Malawi

ARF-D

ARC 1950, Swaziland

ARF-E

ARC 1950, Zaire

ARF-F

ARC 1950, Zambia

ARF-G

ARC 1950, Zimbabwe

ARF-H

ARC 1950, Burundi

ARF-M

ARC 1950, Mean

ARS

ARC 1960, Kenya & Tanzania

ASC

ASCENSION ISLAND 1958

ASM

MONTSERRAT ISLAND ASTRO 1958

ASQ

ASTRO STATION 1952, Marcus Is.

ATF

ASTRO BEACON E 1845, Iwo Jima

AUA

AUSTRALIAN GEODETIC 1966

AUG

AUSTRALIAN GEODETIC 1984

BAT

DJAKARTA, INDONESIA

BER

BERMUDA 1957, Bermuda Islands

BID

BISSAU, Guinea-Bissau

BOO

BOGOTA OBSERVATORY, Columbia

BUR

BUKIT RIMPAH, Banka & Belitung

CAC

CAPE CANAVERAL, Florida & Bahamas

CAI

CAMPO INCHAUSPE 1969, Argentina

CAO

CANTON ASTRO 1966, Phoenix Is.

CAP

CAPE, South Africa

CAZ

CAMP AREA ASTRO, Camp McMurdo

CCD

S-JTSK, Czech Republic

CGE

CARTHAGE, Tunisia

CHI

CHATHAM ISLAND ASTRO 1971, NZ

CHU

CHUA ASTRO, Paraguay

COA

CORREGO ALEGRE, Brazil

DAL

DABOLA, Guinea

DID

DECEPTION ISLAND

DOB

GUX 1 ASTRO, Guadalcanal Is.

EAS

EASTER ISLAND 1967

ENW

WAKE-ENIWETOK 1960

EUR-7

EUROPEAN 1950, Mean (7-Parameter)

EUR-A

EUROPEAN 1950, Western Europe

EUR-B

EUROPEAN 1950, Greece

EUR-C

EUROPEAN 1950, Norway & Finland

EUR-D

EUROPEAN 1950, Portugal & Spain

EUR-E

EUROPEAN 1950, Cyprus

EUR-F

EUROPEAN 1950, Egypt

EUR-G

EUROPEAN 1950, England, Channel

EUR-H

EUROPEAN 1950, Iran

EUR-I

EUROPEAN 1950, Sardinia (Italy)

EUR-J

EUROPEAN 1950, Sicily (Italy)

EUR-K

EUROPEAN 1950, England, Ireland

EUR-L

EUROPEAN 1950, Malta

EUR-M

EUROPEAN 1950, Mean (3-Parameter)

EUR-S

EUROPEAN 1950, Iraq, Israel

EUR-T

EUROPEAN 1950, Tunisia

EUS

EUROPEAN 1979

FAH

OMAN

FLO

OBSERVATORIO MET. 1939, Flores

FOT

FORT THOMAS 1955, Leeward Is.

GAA

GAN 1970, Rep. of Maldives

GEO

GEODETIC DATUM 1949, NZ

GIZ

DOS 1968, Gizo Island

GRA

GRACIOSA BASE SW 1948, Azores

GUA

GUAM 1963

GSE

GUNUNG SEGARA, Indonesia

HEN

HERAT NORTH, Afghanistan

HIT

PROVISIONAL SOUTH CHILEAN 1963

HJO

HJORSEY 1955, Iceland

HKD

HONG KONG 1963

HTN

HU-TZU-SHAN, Taiwan

IBE

BELLEVUE (IGN), Efate Is.

IDN

INDONESIAN 1974

IND-B

INDIAN, Bangladesh

IND-I

INDIAN, India & Nepal

IND-P

INDIAN, Pakistan

INF-A

INDIAN 1954, Thailand

ING-A

INDIAN 1960, Vietnam 16N

ING-B

INDIAN 1960, Con Son Island

INH-A

INDIAN 1975, Thailand

IRL

IRELAND 1965

ISG

ISTS 061 ASTRO 1968, S Georgia

IST

ISTS 073 ASTRO 1969, Diego Garcia

JOH

JOHNSTON ISLAND 1961

KAN

KANDAWALA, Sri Lanka

KEA

KERTAU 1948, W Malaysia & Sing.

KEG

KERGUELEN ISLAND 1949

KUS

KUSAIE ASTRO 1951, Caroline Is.

LCF

L.C. 5 ASTRO 1961, Cayman Brac

LEH

LEIGON, Ghana

LIB

LIBERIA 1964

LUZ-A

LUZON, Philippines

LUZ-B

LUZON, Mindanao Island

MAS

MASSAWA, Ethiopia

MER

MERCHICH, Morocco

MID

MIDWAY ASTRO 1961, Midway Is.

MIK

MAHE 1971, Mahe Is.

MIN-A

MINNA, Cameroon

MIN-B

MINNA, Nigeria

MOD

ROME 1940, Sardinia

MPO

M'PORALOKO, Gabon

MVS

VITI LEVU 1916, Viti Levu Is.

NAH-A

NAHRWAN, Masirah Island (Oman)

NAH-B

NAHRWAN, United Arab Emirates

NAH-C

NAHRWAN, Saudi Arabia

NAP

NAPARIMA, Trinidad & Tobago

NAR-A

NORTH AMERICAN 1983, Alaska

NAR-B

NORTH AMERICAN 1983, Canada

NAR-C

NORTH AMERICAN 1983, CONUS

NAR-D

NORTH AMERICAN 1983, Mexico

NAR-E

NORTH AMERICAN 1983, Aleutian

NAR-H

NORTH AMERICAN 1983, Hawai'i

NAS-A

NORTH AMERICAN 1927, Eastern US

NAS-B

NORTH AMERICAN 1927, Western US

NAS-C

NORTH AMERICAN 1927, CONUS

NAS-D

NORTH AMERICAN 1927, Alaska

NAS-E

NORTH AMERICAN 1927, Canada

NAS-F

NORTH AMERICAN 1927, Alberta/BC

NAS-G

NORTH AMERICAN 1927, E. Canada

NAS-H

NORTH AMERICAN 1927, Man/Ont

NAS-I

NORTH AMERICAN 1927, NW Terr.

NAS-J

NORTH AMERICAN 1927, Yukon

NAS-L

NORTH AMERICAN 1927, Mexico

NAS-N

NORTH AMERICAN 1927, C. America

NAS-O

NORTH AMERICAN 1927, Canal Zone

NAS-P

NORTH AMERICAN 1927, Caribbean

NAS-Q

NORTH AMERICAN 1927, Bahamas

NAS-R

NORTH AMERICAN 1927, San Salv.

NAS-T

NORTH AMERICAN 1927, Cuba

NAS-U

NORTH AMERICAN 1927, Greenland

NAS-V

NORTH AMERICAN 1927, Aleutian E

NAS-W

NORTH AMERICAN 1927, Aleutian W

NSD

NORTH SAHARA 1959, Algeria

OEG

OLD EGYPTIAN 1907

OGB_7

ORDNANCE GB 1936, Mean (7-Parameter)

OGB-A

ORDNANCE GB 1936, England

OGB-B

ORDNANCE GB 1936, Eng., Wales

OGB-C

ORDNANCE GB 1936, Scotland

OGB-D

ORDNANCE GB 1936, Wales

OGB-M

ORDNANCE GB 1936, Mean (3-Parameter)

OHA-A

OLD HAWAI'IAN (CC), Hawai'i

OHA-B

OLD HAWAI'IAN (CC), Kauai

OHA-C

OLD HAWAI'IAN (CC), Maui

OHA-D

OLD HAWAI'IAN (CC), Oahu

OHA-M

OLD HAWAI'IAN (CC), Mean

OHI-A

OLD HAWAI'IAN (IN), Hawai'i

OHI-B

OLD HAWAI'IAN (IN), Kauai

OHI-C

OLD HAWAI'IAN (IN), Maui

OHI-D

OLD HAWAI'IAN (IN), Oahu

OHI-M

OLD HAWAI'IAN (IN), Mean

PHA

AYABELLA LIGHTHOUSE, Bjibouti

PIT

PITCAIRN ASTRO 1967

PLN

PICO DE LAS NIEVES, Canary Is.

POS

PORTO SANTO 1936, Madeira Is.

PRP-A

PROV. S AMERICAN 1956, Bolivia

PRP-B

PROV. S AMERICAN 1956, N Chile

PRP-C

PROV. S AMERICAN 1956, S Chile

PRP-D

PROV. S AMERICAN 1956, Colombia

PRP-E

PROV. S AMERICAN 1956, Ecuador

PRP-F

PROV. S AMERICAN 1956, Guyana

PRP-G

PROV. S AMERICAN 1956, Peru

PRP-H

PROV. S AMERICAN 1956, Venezuela

PRP-M

PROV. S AMERICAN 1956, Mean

PTB

POINT 58, Burkina Faso & Niger

PTN

POINT NOIRE 1948

PUK

PULKOVO 1942, Russia

PUR

PUERTO RICO & Virgin Is.

QAT

QATAR NATIONAL

QUO

QORNOQ, South Greenland

REU

REUNION, Mascarene Is.

SAE

SANTO (DOS) 1965

SAN-A

SOUTH AMERICAN 1969, Argentina

SAN-B

SOUTH AMERICAN 1969, Bolivia

SAN-C

SOUTH AMERICAN 1969, Brazil

SAN-D

SOUTH AMERICAN 1969, Chile

SAN-E

SOUTH AMERICAN 1969, Colombia

SAN-F

SOUTH AMERICAN 1969, Ecuador

SAN-G

SOUTH AMERICAN 1969, Guyana

SAN-H

SOUTH AMERICAN 1969, Paraguay

SAN-I

SOUTH AMERICAN 1969, Peru

SAN-J

SOUTH AMERICAN 1969, Baltra

SAN-K

SOUTH AMERICAN 1969, Trinidad

SAN-L

SOUTH AMERICAN 1969, Venezuela

SAN-M

SOUTH AMERICAN 1969, Mean

SAO

SAO BRAZ, Santa Maria Is.

SAP

SAPPER HILL 1943, E Falkland Is

SCK

SCHWARZECK, Namibia

SGM

SELVAGEM GRADE 1938, Salvage Is

SHB

ASTRO DOS 71/4, St. Helena Is.

SOA

SOUTH ASIA, Singapore

SPK

S-42 (PULKOVO 1942), Hungary

TAN

TANANARIVE OBSERVATORY 1925

TDC

TRISTAN ASTRO 1968

TIL

TIMBALAI 1948, Brunei & E Malay

TOY-A

TOKYO, Japan

TOY-C

TOKYO, Okinawa

TOY-B

TOKYO, South Korea

TOY-M

TOKYO, Mean

TRN

ASTRO TERN ISLAND (FRIG) 1961

VOR

VOIROL 1960, Algeria

WAK

WAKE ISLAND ASTRO 1952

YAC

YACARE, Uruguay

ZAN

ZANDERIJ, Suriname

 

Example

// Convert from HJORSEY (Iceland) to WGS84

...

{"NAD Conversion", "HJO", "WGS84",}

 

 

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