Why does the Kinsman app use three different height systems?

Our app supports three height systems because each one serves a different purpose in real-world construction and surveying workflows. Together, they give you both accuracy and flexibility on-site.

1. Sea Level (NAVD88) — Default Display

The primary height you see throughout the app is based on North American Vertical Datum of 1988 (NAVD88).

• This represents elevation relative to mean sea level.
• It’s the standard for construction and surveying projects in the U.S.
• All points are automatically converted into NAVD88 so your elevations match plans, benchmarks, and engineering data.

In short: This is your “real-world” elevation.

2. Benchmark (Manual Adjustment) — User-Controlled Display

The Benchmark feature lets you change displayed elevations to match job site needs.

• You can select any point and assign it a known elevation (this is called setting a benchmark).
• The app will then adjust all other displayed heights relative to that value.

Common uses:

• Set a reference elevation (e.g., make a point = 100.00 ft so everything reads relative to it).
• Correct small offsets in sea level data:
  • Example: If NAVD88 shows 420.00 ft but the surveyed value is 421.35 ft, set a benchmark to 421.35 ft.
  • The app shifts all elevations so everything aligns correctly.

In short: This is your “job site display height adjustment tool.”

3. GNSS (WGS84) — Raw Measurement

All points in the system are originally measured using World Geodetic System 1984 (WGS84).

• This is ellipsoidal height, based on satellite positioning.
• It’s the raw value coming directly from the GNSS receiver.
• These values are typically not used directly in construction because they don’t match sea level elevations without conversion.

In short: This is the “source data” from satellites.

How they work together

• WGS84 (GNSS) → raw measurement from satellites
• NAVD88 (Sea Level) → converted, real-world elevation (default)
• Benchmark → optional adjustment for site-specific accuracy

Quick summary

• Use NAVD88 for standard elevations
• Use Benchmark to match site conditions or plans
• Use WGS84 only if you need raw GNSS data