### Measurements in Land Surveying

When reading legal land survey descriptions there are several things a land surveyor must keep in mind to conduct a proper survey. For example, the following legal description is for a 42- acre parcel – T39N, R23W, Sec. 4, NW1/4 SE1/4.

First, one must understand that punctuation is crucial in reading legal land surveys.  If a comma were included in between the “NW1/4” and “SE1/4” of this legal measurement/description then it would alter the reading to be for a 320 acre parcel.  Second, all legal descriptions are read backwards.  The legal land survey description is read from right to left, going from the smallest unit of measurement to the largest unit of measurement.  Understanding these key points will enable you to conduct a more precise and accurate survey.

The Rectangular Survey System

Land surveying consists largely of determining the measurements of parcels of land.  The Rectangular Survey System or the Public Land Survey System (PLSS) is the primary type of land survey measurement system that the majority of the United States has been surveyed by.  It is a system that is setup on a grid in which the primary objective is to determine approximate values of square sections measuring 1 square mile each (1 square mile = 5,280 feet).  The rectangular survey system is the most common system land surveyors use throughout their career to define accurate and precise measurements.

In order to apply the rectangular survey system you must first understand a couple terms.  These include prime meridiansbaselines, and principal meridians.  Prime Meridians are north-south lines (lines of longitude), at which longitude is defined to be 0°.  The Prime Meridian starts at the North Pole and extends south to the South Pole.  Baselines are lines that extend east-west.  Principal meridians are the true north-south lines that run through the initial point of the area that is being covered.

All measurement starts at an initial point.  Initial points in land surveying are usually set by astronomical observation.  Across the United States there are 37 points where a principal meridian and baseline intersect.  From each of these initial points, a prime meridian extends north-south, and a baseline extends east-west.  Along the north-south prime meridian, initial points are marked at 24 mile intervals.  Baselines extend from east to west from these points as well.  Along the east-west baselines, points are marked at 24 mile intervals as beginning from the north-south prime meridian.  The parallel points created from these points are called standard corners.

For each standard corner a line runs true north.  These lines are called guide meridians.  Due to the Earth’s curvature, guide meridians do not intersect through standard corners along the next standard parallel, 24 miles to the north.  The intersections they cross are called closing corners.  Each standard now contains a set of both standard and closing corners.

Each 24-mile tract is divided up into 16 townships. Townships are roughly 6 miles x 6 miles.  Starting at the southeast corner of the 24-mile tract, corners are established six miles apart along the east-west parallel and the north-south meridians. From these corners, range lines run true north to the next parallel, and township lines run west to the next prime meridian.  With that said, each township is now divided into 36 sections, a piece of land roughly 1 square mile x 1 square mile, or approximately 640 acres.  This process is also used in defining corners and running lines from the southeast corner of the township.  Each of the 36 sections is then divided into 16 forties.  These forties are further subdivided, and subdivided, and subdivided.

Survey Legend

Land Surveyors United Community

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

### Featured Land Surveying Articles

Surveying Articles is a place for members to Share Land Surveying related articles, presentations and knowledge with the Land Surveyors United Community. Post or embed articles for future generations of land surveyors.

### Surveying Articles and Presentations

Do you have an article about Land Surveying that you would like to share?

Land Surveying is a timeless art and science and it is therefore, evergreen! You may also know that a lot of older publications have gone away, unfortunately.   If you have written or published land surveying articles in the past, we would be honored for you to share them here with us.  If it is an older article, you can even republish it here with updates and reflections.

class="block"Tip:   If you published an article in the past on one of the older sites which no longer exist, you can use the Wayback Machine to find it.  Then just copy/paste the old article inside a new post here.  Just be sure to tell us where it was previously posted.

Want to embed a PDF Document?

If you have a PDF document or article related to land surveying that you would like to embed inside an article post, simply copy/paste the following code block into the HTML view of the post editor and replace the BOLD part of the code with the URL of the PDF you'd like to embed.

Code to use:

TIP:  You can also upload your PDF using the file upload button and then copy/paste the URL of the document you uploaded with the BOLD part of the code above to get a flippable PDF like so:

Differences between Forums, Blogs and Article posts

Blog Postsdiffer from Forum posts because you can embed and upload different kinds of information.  Blog posts are best for presenting information and updates for feedback and sharing.  When posting a Blog Post, you can also publish a short excerpt at the bottom which is what most members will see before reading the blog post.  Blog posts are also great for posting new surveying projects and digests of links to multiple surveying topics or your own website.   Things that can be embedded into Blog Posts are videos, images, slideshows, powerpoints, spreadsheets, PDFs, documents and more.

Articles are similar to Blog Posts in all ways except one.  Articles allow for you to post an Author Block at the bottom with links to your contact info, website information, credentials, etc. Similar to Blog Posts, things that can be embedded into Blog Posts are videos, images, slideshows, powerpoints, spreadsheets, PDFs, documents and more.  Similar to both types above, Hub Owners can add article sections and features to any hub they control on the community.

### Surveying Jobs

Representing Land Surveyors in 190 Countries
and all 50 US States. Contribute to your local
chapter and promote Land Surveying globally.

Surveyor Hubs

We have members in every region of the planet. Add
your local Land Surveyor events to the calendar and turn
them into Land Surveyors United Meetups worldwide.

Surveyor Events

Inspire the next generation by contributing
your expertise and experience in Land Surveying
to our 20k+ Surveyor Hive Mind. Mentor the Green!

Mentorship