Show us why the public should always call a land surveyor

Where are you surveying?

Land Surveyor

The Excel Resection by Angles Computation is a surveying calculation method used to determine the coordinates of an unknown point (station) by measuring angles and distances from three or more known points (reference objects or ROs) with known coordinates.

The Excel Resection by Angles Computation

The input data required for this computation include the measured azimuth, the known coordinates of the reference objects (ROs), and the angles observed between the ROs and the unknown point (station).

The computation involves several steps, including converting the measured azimuth to a computed bearing, calculating the interior angles between the ROs and the unknown point, and applying trigonometric functions to determine the unknown point's coordinates.

The computation is performed using an Excel spreadsheet, which simplifies the calculations and allows for easy manipulation of the input data and results.

It is important to note that the known RO coordinates must be entered or observed in a clockwise direction to ensure the correct computation of the interior angles.


You need to be a member of Land Surveyors United - Global Surveying Community to add thoughts!

Join Land Surveyors United - Global Surveying Community

Email me when people reply –


  • Land Surveyor

    What's never pointed out when discussing three-point resection is, fromĀ,

    When planning to perform a resection, the surveyor must first plot the locations of the known points along with the approximate unknown point of observation. If all points, including the unknown point, lie close to a circle that can be placed on all four points, then there is no solution or the high risk of an erroneous solution. This is known as observing on the "danger circle". The poor solution stems from the property of a chord subtending equal angles to any other point on the circle.

    Position resection and intersection
    Position resection and intersection are methods for determining an unknown geographic position (position finding) by measuring angles with respect to…
  • This is my Excel sheet from 2009 and can be found here (along with others):

This reply was deleted.

Answer As your Facebook Page

Global Surveyor Forum

Latest Discussions by Category

Add Your Expertise

How to Utilize Surveyor Forums

How to use Forums
Our forums on Land Surveyors United are here to be used as much for finding help with problems in the field as the are for you to express your opinions on anything that has to do with land surveying in general. Feel free to share anything that is on your mind, as long as it isn't meant to damage another member's reputation. Please keep it clean and help insure that everyone has the opportunity to enjoy the benefits of being part of a community that grows together.

We are committed to allowing freedom of expression for all of our members, and that includes maintaining a safe space for people with opposing views to express themselves. We get posts from all over the country and even the globe, so needless to say, people come with different viewpoints on lad surveying practices and processes. We see this diversity and variety as a real strength-- dialogue and debate are an integral part of the educational process, as well as an important tool in exploring different sides of complex issues.

All Community Hubs inside the community have their own forum for asking specific questions to other surveyors, by location, equipment type, etc.

Global Forums

Blog Topics by Tags

Monthly Archives