i have 2 control points created by GPS on my new project, and my Total station without Scale factor (Leica 407)

So, the Orientation get 16 cm difference 

What should i Do?

This Content Originally Published by a land surveyor to Land Surveyors United Network

Views: 2241

See Your Saved Posts Timeline

☇ Reply to this

Replies to This Discussion

First point... GPS ALWAYS works on WGS84. The only issue you can do is to transform those coordinates to whatever system you are interested.

Second Point, making a projection with a GIS means... nothing? Depends of which projection are you interested in... (Projection is not the correct word, it is only for geometry, for us it is a transformation)

I will put an example... You made your observations with GPS, and then you have used your GIS software to transform it on some other system, for example, UTM. If you are using UTM, this system have always a factor scale, so whatever you are designing, will have a factor scale in our ground.

If you want to use GPS and TS data without taking care of a factor scale, you should setup your GIS software for the Datum you are interested in, the coordinates system you are interested in and a factor scale = 1.0000000. Then, you can use data from one or another source.

But keep in mind that in order to make this transformation, GIS software won´t do that, because they have implemented global transformations as UTM, for example, so it is required to place some benchmarks with global coordinates and no factor scale, and force to your GIS software to make a transformation between the global coordinates without factor scale to your GPS Data.

Clear example... You need to survey an area when you can make some observations with GPS and some observations with TS. So first of all you should place some benchmarks and observe it without factor scale (It means, forget your GPS and use your TS to bring non-factor scale coordinates). Once that you have that coordinates, the observ that benchmarks with your GPS and force your GPS to make a transformation between WGS84 to your local system without factor scale. Once that you have it, you can use GPS or TS freely.

But if you have made your GPS observations, you have transform it with any GIS system, then you got a projected coordinates that USUALLY will have a factor scale. So if you are using a TS upon this data, you will get some closing errors. If that points are very closed, it will seem that it is an instrumental error, but if they are very far, you will have huge errors... Depends on the projection you are using in your GIS system and your position in the projection area.

hello sir I have two gps wgs84 coordinate with scale factor of0.9996 how can I convert it to local coordinates with scale factor of 1

Dear Raymond...

Is not as simple as this.

WGS84 is just a elipsoid, so you have Lat and Long, not X&Y.

In order to get there you need a Datum and a Projection.

Which Datum are you using? (Maybe Umm Er Rus Datum, Midra Jinubi Alignment, Clark 1866)

Which Projection are you using? (ARAMCO Gauss-Krüger Transverse Mercator?)

With these data, we can know how to transform Lat/Long to X/Y, and later we can talk regarding factor scale. If you can provide me those data, we will manage

sir but the client gived me two xy coordinates and they told me this is wgs 84 coordinate 37q zone with scale factor of0.9996

Dear Raymond:

Take a look to https://en.wikipedia.org/wiki/World_Geodetic_System and you will see that there are no coordinates on WGS84.

But your client told you that you are on zone 37q, so you are using an UTM system (take a look at https://en.wikipedia.org/wiki/Universal_Transverse_Mercator_coordin...) and you are in Saudi Arabia.

In Saudi Arabia, the oficial Datum is Umm Er Rus, with Midra Jinubi Alignment using Clark 1866 elipsoid (not WGS84). The official projection in Saudi Arabia is ARAMCO Gauss-Krüger Tranverse Mercator.

Please, ask to your client if they have used this Datum and Projection and then we will bring new coordinates.

Regards

Means is it a utm coordinate sir....
Is utm is a cartesian coordinate system

UTM is a projection system. It is cartesian but every single point has a different factor scale. Please, send me a sketch of what you have an will give you and idea.

yes it's really useful 

hello  Amhed, i am DONE!!

RSS

Where Thousands of Professional Land Surveyors, Students of Surveying and Educators are United through Collaborative Knowledge and Purpose.

Dedicated to the Memory of Skip Farrow (1953-2015)

+ Surveyor Sharer

Drag Button to bookmark bar and view submitted links here.Will soon be moved to a directory

AFGHANISTAN SURVEYORS ALBANIA SURVEYORS ALGERIA SURVEYORS AMERICAN SAMOA SURVEYORS ANDORRA SURVEYORS
ANGOLA SURVEYORS ANGUILLA SURVEYORS ANTIGUA & BARBUDA SURVEYORS ARGENTINA SURVEYORS ARMENIA SURVEYORS
ARUBA SURVEYORS AUSTRALIA SURVEYORS AUSTRIA SURVEYORS AZERBAIJAN SURVEYORS BAHAMAS SURVEYORS
BAHRAIN SURVEYORS BANGLADESH SURVEYORS BARBADOS SURVEYORS BELARUS SURVEYORS BELGIUM SURVEYORS
BELIZE SURVEYORS BENIN SURVEYORS BERMUDA SURVEYORS BHUTAN SURVEYORS BOLIVIA SURVEYORS
BOSNIA & HERZEGOWINA SURVEYORS BOTSWANA SURVEYORS BRAZIL SURVEYORS BRITISH INDIAN OCEAN TERRITORY SURVEYORS
BRUNEI DARUSSALAM SURVEYORS BULGARIA SURVEYORS BURKINA FASO SURVEYORS BURUNDI SURVEYORS CAMBODIA SURVEYORS
CAMEROON SURVEYORS CANADA SURVEYORS CAPE VERDE SURVEYORS CAYMAN ISLANDS SURVEYORS CENTRAL AFRICAN REPUBLIC SURVEYORS
CHAD SURVEYORS CHILE SURVEYORS CHINA SURVEYORS COLOMBIA SURVEYORS COMOROS SURVEYORS
CONGO SURVEYORS DEMOCRATIC REPUBLIC OF THE CONGO SURVEYORS COOK ISLANDS SURVEYORS COSTA RICA SURVEYORS COTE D'IVOIRE SURVEYORS
CROATIA SURVEYORS CUBA SURVEYORS CURACAO SURVEYORS CYPRUS SURVEYORS CZECH REPUBLIC SURVEYORS
DENMARK SURVEYORS DJIBOUTI SURVEYORS DOMINICA SURVEYORS DOMINICAN REPUBLIC SURVEYORS ECUADOR SURVEYORS
EGYPT SURVEYORS EL SALVADOR SURVEYORS EQUATORIAL GUINEA SURVEYORS ERITREA SURVEYORS ESTONIA SURVEYORS
ETHIOPIA SURVEYORS EUROPEAN UNION SURVEYORS FAROE ISLANDS SURVEYORS FIJI SURVEYORS FINLAND SURVEYORS
FRANCE SURVEYORS FRENCH GUIANA SURVEYORS FRENCH POLYNESIA SURVEYORS GABON SURVEYORS GAMBIA SURVEYORS
GEORGIA SURVEYORS GERMANY SURVEYORS GHANA SURVEYORS GIBRALTAR SURVEYORS GREECE SURVEYORS
GREENLAND SURVEYORS GRENADA SURVEYORS GUADELOUPE SURVEYORS GUAM SURVEYORS GUATEMALA SURVEYORS
GUERNSEY SURVEYORS GUINEA SURVEYORS GUINEA-BISSAU SURVEYORS GUYANA SURVEYORS HAITI SURVEYORS
HOLY SEE SURVEYORS HONDURAS SURVEYORS HONG KONG SURVEYORS HUNGARY SURVEYORS ICELAND SURVEYORS
INDIA SURVEYORS INDONESIA SURVEYORS IRAN SURVEYORS IRAQ SURVEYORS IRELAND SURVEYORS
ISLE OF MAN SURVEYORS ISRAEL SURVEYORS ITALY SURVEYORS JAMAICA SURVEYORS JAPAN SURVEYORS
JERSEY SURVEYORS JORDAN SURVEYORS KAZAKHSTAN SURVEYORS KENYA SURVEYORS KIRIBATI SURVEYORS
KOREA SURVEYORS KOREA REPUBLIC OF SURVEYORS KUWAIT SURVEYORS KYRGYZSTAN SURVEYORS LAO PEOPLE'S DEMOCRATIC REPUBLIC SURVEYORS
LATVIA SURVEYORS LEBANON SURVEYORS LESOTHO SURVEYORS LIBERIA SURVEYORS LIBYAN ARAB JAMAHIRIYA SURVEYORS
LIECHTENSTEIN SURVEYORS LITHUANIA SURVEYORS LUXEMBOURG SURVEYORS MACAU SURVEYORS MACEDONIA SURVEYORS
MADAGASCAR SURVEYORS MALAWI SURVEYORS MALAYSIA SURVEYORS MALDIVES SURVEYORS MALI SURVEYORS
MALTA SURVEYORS MARSHALL ISLANDS SURVEYORS MARTINIQUE SURVEYORS MAURITANIA SURVEYORS MAURITIUS SURVEYORS
MAYOTTE SURVEYORS MEXICO SURVEYORS MICRONESIA SURVEYORS MOLDOVA SURVEYORS MONACO SURVEYORS
MONGOLIA SURVEYORS MONTENEGRO SURVEYORS MONTSERRAT SURVEYORS MOROCCO SURVEYORS MOZAMBIQUE SURVEYORS
MYANMAR SURVEYORS NAMIBIA SURVEYORS NAURU SURVEYORS NEPAL SURVEYORS NETHERLANDS SURVEYORS
NEW CALEDONIA SURVEYORS NEW ZEALAND SURVEYORS NICARAGUA SURVEYORS NIGER SURVEYORS NIGERIA SURVEYORS
NIUE SURVEYORS NON-SPEC ASIA PAS LOCATION SURVEYORS NORFOLK ISLAND SURVEYORS NORTHERN MARIANA ISLANDS SURVEYORS NORWAY SURVEYORS
OMAN SURVEYORS PAKISTAN SURVEYORS PALAU SURVEYORS PALESTINIAN TERRITORY OCCUPIED SURVEYORS PANAMA SURVEYORS
PAPUA NEW GUINEA SURVEYORS PARAGUAY SURVEYORS PERU SURVEYORS PHILIPPINES SURVEYORS POLAND SURVEYORS
PORTUGAL SURVEYORS PUERTO RICO SURVEYORS QATAR SURVEYORS RESERVED SURVEYORS REUNION SURVEYORS
ROMANIA SURVEYORS RUSSIAN FEDERATION SURVEYORS RWANDA SURVEYORS SAINT KITTS & NEVIS SURVEYORS SAINT LUCIA SURVEYORS
SAINT MARTIN SURVEYORS SAINT VINCENT & THE GRENADINES SURVEYORS SAMOA SURVEYORS SAN MARINO SURVEYORS SAO TOME & PRINCIPE SURVEYORS
SAUDI ARABIA SURVEYORS SENEGAL SURVEYORS SERBIA SURVEYORS SEYCHELLES SURVEYORS SIERRA LEONE SURVEYORS
SINGAPORE SURVEYORS SINT MAARTEN SURVEYORS SLOVAKIA (SLOVAK REPUBLIC) SURVEYORS SLOVENIA SURVEYORS SOLOMON ISLANDS SURVEYORS
SOMALIA SURVEYORS SOUTH AFRICA SURVEYORS SOUTH SUDAN SURVEYORS SPAIN SURVEYORS SRI LANKA SURVEYORS
ST. PIERRE AND MIQUELON SURVEYORS SUDAN SURVEYORS SURINAME SURVEYORS SWAZILAND SURVEYORS SWEDEN SURVEYORS
SWITZERLAND SURVEYORS SYRIAN ARAB REPUBLIC SURVEYORS TAIWAN; REPUBLIC OF CHINA (ROC) SURVEYORS TAJIKISTAN SURVEYORS TANZANIA UNITED REPUBLIC OF SURVEYORS
THAILAND SURVEYORS TIMOR-LESTE SURVEYORS TOGO SURVEYORS TOKELAU SURVEYORS TONGA SURVEYORS
TRINIDAD AND TOBAGO SURVEYORS TUNISIA SURVEYORS TURKEY SURVEYORS TURKMENISTAN SURVEYORS TURKS AND CAICOS ISLANDS SURVEYORS
TUVALU SURVEYORS UGANDA SURVEYORS UKRAINE SURVEYORS UNITED ARAB EMIRATES SURVEYORS UNITED KINGDOM SURVEYORS
UNITED STATES SURVEYORS URUGUAY SURVEYORS UZBEKISTAN SURVEYORS VANUATU SURVEYORS VENEZUELA SURVEYORS
VIET NAM SURVEYORS VIRGIN ISLANDS (BRITISH) SURVEYORS VIRGIN ISLANDS (U.S.) SURVEYORS WALLIS AND FUTUNA ISLANDS SURVEYORS YEMEN SURVEYORS
ZAMBIA SURVEYORS ZIMBABWE SURVEYORS SURVEYORS

Location Based Surveying Practices

Land Surveyors United is the world's FIRST Global Social Network for geospatial professionals. We have dedicated, geolocated support groups for practically every country, continent and state on earth, for you to utilize for building your personal network. We are all essentially concerned with the same issues, no matter where we are located on earth. However, surveying practices and methods vary depending on the geographic location where we work. If you have noticed similarities and differences between the conditions, laws and practices between two or more areas of the world,discuss it in this forum. Build your reputation online by posting relevant discussions in your local group below.

Join and Introduce Yourself in Your Local Geosocial Forum:

Alabama Alaska Arizona Arkansas California
Colorado Connecticut Delaware Florida Georgia
Hawaii Idaho Illinois Indiana Iowa
Kansas Kentucky Louisiana Maine Maryland
Massachusetts Michigan Minnesota Mississippi Missouri
Montana Nebraska Nevada New Hampshire New Jersey
New Mexico New York North Carolina North Dakota Ohio
Oklahoma Oregon Pennsylvania Rhode Island South Carolina
South Dakota Tennessee Texas Utah Vermont
Virginia Washington West Virginia Wisconsin Wyoming

Not based in the US? Here are other groups for surveyors around the world to join and contribute knowledge and experiences as a land surveyor:

Africa Asia Australia Europe Russia Canada
Antarctica S.America N. America India Malaysia Caribbean

And more... Find your group forum based on location.

Choose Your Equipment Group Here

Handheld US Social Support for Land SurveyorsNIKON Social Support for Land SurveyorsTrimble Social Support for Land SurveyorsTopcon Social Support for Land SurveyorsSokkia Social Support for Land SurveyorsAshtech Social Support for Land SurveyorsNAVCOM Social Support for Land SurveyorsMagellan Social Support for Land SurveyorsLeica Social Support for Land SurveyorsAltus Positioning Social Support for Land SurveyorsMicroSurvey Social Support for Land SurveyorsJuniper Systems Social Support for Land SurveyorsTraverse PC Social Support for Land SurveyorsCarlson Software Social Support for Land Surveyors

what where  
job title, keywords or company
city, state or zip jobs by job search

PLEASE DONATE TODAY. Your generosity preserves surveying and mapping knowledge for future generations. Thank you.

Survey Equipment Troubles?

Geo Visitors Map

Choose Your Group Here

Surveying Equipment Support for Leica, Carlson, Sokkia, Trimble, Topcon, Altus, Nikon equipment


Surveyor Birthdays

© 2017   © Created by Land Surveyors United   Powered by

Badges  |  Contact LSU  |  Privacy Policy  |  Terms of Service

Live Support