Hie guys, I have a challenge here. I have been placed on a new site, working with another surveyor from a different company. We all used same initial control points and transferred to local control on the site. He is working on the deck and  i am working on the foundation. One of the days he wasn't around and i was asked to put some marks on the decks for grid lines. When the other surveyor came back he checked my points and they were varying from his by 15mm on the X and 21mm on the Y consistently on all the points. I concluded the problem must be with the control points he had transferred to or i had transferred to. The site manager wasn't happy about it and doesn't care who is right or wrong. he wants us to harmonize our control. how do we do that considering that i have been using the same control for the foundation whilst he has been using his own for the decks. Or preferably is there any other way of dealing with such a scenario. Most importantly, the tolerance for the job is -5mm to +10mm.

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

Views: 691

See Your Saved Posts Timeline

☇ Reply to this

Replies to This Discussion

Have you checked you used the correct prism constants?

Have you checked that you haven't transposed some of the coords?

Maybe both you guys need to re-establish the main site control.

Can you get around it on this building by adopting his control from now on, the tolerances on the foundations should permit this.

Use Geolab to adjust the points. The other issue is what datum you are in? Are you using grid coordinates or ground coordinates?

We have this all the time at my survey office here in Canada

 Hi Killivien, This can happen on a construction site, it has happen to me, if you two are using the same coordinates system you can compare other points before checking your  equipment , it maybe something went wrong that day. work with him and test both guns on a side ,angle side triangle and see if both are the same under the same conditions, this will give you a test of both equipment it maybe a rod is out, either way

this will test dist and angle of each gun and compare calculated dist to shot dist of the missing side this will check your gun and his, also swap rods on a dist check. I have found that working with someone is better than not , but this is a two way street. Good luck

thanks guys, great ideas, I will make use of your suggestions. Maurice, I am working on ground coordinates which were used to come up with the grids.

Killivien, If the both of you use mixed tribrach and rods make sure they are the same dist. in reason of each other, is this error all base on total sta.  Data, that is what i was assuming . this could also be accumulated error how many setup was involved to set or check these points.

Create the Triangle with new coordinates, both of you should have a very close triangle data, about 200 meters are150 meters dist, the triangle will check your equipment do a side, angle side, then shoot the dist. on all the points if you like check all three angles, they should match in reason of the calculated triangle if there is anything wrong it will show up here.then you will know where the error is, and if something needs to be fixed. also is there heavy vibration going on around the survey, there can be a lot reason for this. First make sure you both turn the same angles and shoot the same dist. then go from there.

Hi Sithole. Did you survey in all the point you set out? I would say take all his point surveyed and yours put it into modelmaker and overlay it in 2 different projects. Then in Project 3 put the design point and check whos is over lapping the most using the control points as the main point of transformation.

Regards

If you work for contractor,the consultant should provide approved values of controled to be used,so if you have used those and do your job it is ok,can't find fault with contractor,
This matter has to be directed to consultants and get an approved solution,otherwise some fault will have to be beared by you,
As I was the consultat surveyor in some projects and contractor surveyor for some projects.
I came across problems like that most were rectified without delaying construction!
Regards,
Lalith
There are a number of possible causes. I think what Mr. Herter said is the most probable cause. Geodetic control, State Plane coordinates or whatever geodetic grid you are working with is great for control of boundaries and reference points. Control for a structure or a building is generally done on a local grid. Within the small area usually associated with a building, there is no significant error due to curvature of the earth or the mapping angle. There is enough discrepancy between the two to cause problems with contractors & architects that like their buildings to be square. You introduce errors when you try to "Hammer Fit", as the U.S., N.G.S. has called it, a rectilinear (regular theodolite/ EDM ) survey to a GPS/Geodetic survey that is based on true latitude & longitude. The two surveys are not the same. The difference between the two is not great but it can be enough to create concern. I would refer the problem to a "higher up" or at least adopt a local grid where a 90 deg. angle is exactly 90 deg. (not almost) & 100 meters is 100 meters on the ground as apposed to on the grid.

I am confused, maybe i ASSuME something, I was under the impression that this survey was in reference to a total station survey, and these points were to a grid layout to a building.SO please someone explain i am lost. Where is the GPS ???, get the hammer out again.

Good Day Mr. Billy

I remember you helped me before with a great reply.

Most of projects managers try to safe cost more than getting accurate job.

so like me i forgot working with GPS. (only when project start)

I think this problem in the prism  constant, or he should check the other surveyor grid.

Regards

Hi Ahmed, Good to here from you,hope you are do well.  No matter what the problem is these two have to work with each other and get on the same page ,if they are using the same coors this is great they can compare northing and easting  or what every they are using,if they came off the same controls with the same values, then they should be in reason of each other.If they can not work together  to solve this, then who is correct.People around the world do things in different ways,so what i think and what i tell you i would do may not be what someone else see's as a solution to the problem. When all else fails go back to the basic,check angles and dist.sums from each equipment to see if they match if it's not equipment problems,then something happen in the process .Do them over ,many times i have been told i was wrong and when i checked i was right and then i proved it. It maybe there is no solution between them this is a give and take. Check everything before you start to adjust anything, You maybe already correct. And do not mix apples and oranges, and make clear when you say you are using this type and the Grid were calculated from them, what kind of Grids.the word grid is used many ways in surveying some prefer to layout buildings by Grid lines plus staking the corners, You can have a defined projection Grid that has it's on Grid Azimuth North that is only good in that Grid, make plain what you are doing,then the solution will be more at hand

Yes, if the other survey was not based on geodetic coordinates, that can't be the problem. Maybe I assumed to much or missed something in your post. That type of disagreement is typical of what happens when you mix the two datum bases so I thought maybe that was the problem. Sorry about that if I was wrong.

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