Surveying Articles

 I saw an interesting post about a Flat Earth map today over on Google Maps Mania today and found myself wondering why this has gotten this far.    From a land surveyor’s standpoint, Gleason’s 1892 New Standard Map of the World is not evidence of a flat Earth — it is an example of a specific map projection doing exactly what it is designed to do.

Gleason’s map uses an azimuthal equidistant projection, a well-known and legitimate cartographic method that surveyors and geodesists still use today. This projection preserves distance and bearing from one central point (in this case, the North Pole). That’s why the map included rotating “hands” or rulers: they allowed a user to measure accurate azimuths and distances outward from the pole only.

However, as any surveyor knows, no flat map can preserve everything. In an azimuthal equidistant projection:

• Distances and bearings from the center are accurate

• Distortion increases rapidly away from the center

• Distances and directions between non-central locations are wrong

So while the map can function as a practical educational or navigational tool from the pole, it fails for comparing distances or routes elsewhere — exactly what geodetic theory predicts.

The modern interactive version by Khaled Mimoune, including adjustable daylight overlays, further illustrates how cartographic projections can visualize real-world phenomena (like illumination and seasons) on a flat surface. From a surveying perspective, this reinforces the distinction between:

• The Earth (a globe)

• A map (a mathematical projection of that globe)

In short, Gleason’s map doesn’t demonstrate a flat Earth. It demonstrates that projecting a curved surface onto a plane requires distortion, a foundational principle in surveying, geodesy, and every State Plane Coordinate System used in professional practice today.

Flat Earth does not survive real-world surveying practice.
Not philosophically, not mathematically, and definitely not in the field.

Surveying is one of the oldest applied sciences on Earth, and we measure curvature whether we intend to or not.

What Surveyors Actually Observe (Not Theory)

1. Level lines are not parallel

On a flat plane, level lines would remain parallel forever. In reality:

• Level lines converge toward Earth’s center

• This is why level loops close only when curvature is accounted for

• Ignore curvature and your elevations drift

Rule of thumb every surveyor learns:

Curvature drop ≈ 0.667 ft per mile²

That’s not a NASA number — that’s a surveying correction.

2. Long-distance leveling proves curvature

If I run a precise level line:

• 1 mile → negligible difference

• 5 miles → measurable

• 20+ miles → impossible to ignore

State DOTs, USACE, and geodetic surveys require curvature and refraction corrections. If Earth were flat, these corrections would introduce errors — but instead they remove them.

3. Triangulation doesn’t work on a flat Earth

In geodetic control:

• Large triangles do not sum to 180°

• The excess increases with triangle area

• That excess matches spherical geometry exactly

This was proven centuries ago and is still used today.

If Earth were flat:

• Control networks would never close

• State Plane Coordinate Systems wouldn’t work

• GNSS solutions would drift uncontrollably

They don’t.

Coordinate Systems Kill Flat Earth Instantly

State Plane Coordinate System (SPCS)

Every U.S. state uses projected coordinates based on:

• An ellipsoid

• A map projection (Lambert, Transverse Mercator)

Why?
Because Earth is curved and we’re flattening it on purpose, carefully.

If Earth were flat:

• No projections needed

• No scale factor

• No convergence angle

Yet we measure:

• Grid vs ground distance differences

• Meridian convergence

• Scale factor changes by location

You can verify this with a total station and two benchmarks.

GNSS Is the Nail in the Coffin

Survey-grade GNSS works because:

• Satellites orbit a curved Earth

• Signal timing assumes an ellipsoid

• Positions are solved in 3D space

If Earth were flat:

• RTK corrections would fail

• Baselines wouldn’t resolve

• Vertical solutions would collapse

Instead, we routinely get:

• Horizontal accuracy < 0.03 ft

• Vertical accuracy < 0.06 ft

Every day. By county surveyors, not space agencies.

“But I Can See Farther Than Curvature Allows”

Surveyor response:

1. Refraction is real

2. Elevations matter

3. Atmospheric ducting happens

4. Line of sight ≠ line of level

Surveyors distinguish between:

• Optical visibility

• Geometric line of sight

• Level surface

• Geoid vs ellipsoid

Flat Earth arguments usually mix all four into one sentence.

Historical Surveying Perspective

Long before satellites:

• Surveyors in the 1700s measured meridian arcs

• Found Earth’s radius within a fraction of a percent

• Using chains, theodolites, and stars

No rockets. No CGI. Just math and patience.

Professional Reality Check

Here’s the blunt PLS truth:

If Earth were flat, surveying as a profession would not work.

• Boundary surveys wouldn’t close

• Control networks would fail

• Elevation datums would drift

• Engineering projects would not align

Yet highways meet.
Bridges connect.
Pipelines close.
And property corners agree.

Why Flat Earth Persists (From a Mentor’s View)

Not stupidity — but:

• Mistrust of institutions

• Misunderstanding of scale

• Confusion between models and reality

• Lack of exposure to field-grade measurement

Once someone runs:

• A 10-mile level loop

• A geodetic control adjustment

• A GNSS baseline across counties

Flat Earth quietly disappears.

Final Word

I’ve surveyed:

• Coastal projects

• Long pipelines

• Multi-county control networks

• High-precision leveling routes

The Earth curves.
We measure it.
We correct for it.
And we get paid because of it.