Tool 03 · COGO calculator

Four survey computations
with no tables and no signal.

Inverse, radiation, intersection and area by coordinates — each on its own tab, with an angle unit you set once that applies to all of them. Every result copies with one tap.

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4 computations
2 angle units
0 signal required
GeoKantar — COGO calculator, inverse and radiation
Tool

Four computations

The same calculations normally done on a total station or back at the office, with input that fits on one screen.

InverseFrom the coordinates of A and B, returns the bearing and distance of line A→B
Radiation (polar)From a station, bearing and distance, returns the coordinates of a new point
Line intersectionTwo lines, each defined by a point and a bearing
Circle intersectionTwo circles, each defined by a point and a radius — up to two solutions
AreaArea and perimeter from a list of typed coordinates, without a map
Angle unitDegrees (°) or gons, set once for all tabs
ResultEvery value has a copy icon that puts it on the clipboard
Procedure

How to use it

01

Set the angle unit

Degrees or gons, at the top of the screen. The choice applies to all four tabs, so units cannot get mixed up.

02

Open a computation tab

Inverse, Radiation, Intersection or Area — the tabs sit along the top.

03

Enter the known values

For inverse, two point coordinates; for radiation, a station, bearing and distance; for intersection, two lines or two circles.

04

Read and copy

The result computes immediately. Tap the icon beside a value to copy it into your field notes or another tool.

Details

When to use which

Inverse — checking and preparing

Inverse returns the bearing and distance between two known points. It is used to check measurements (does the measured distance match the computed one) and to prepare a stakeout.

Radiation — a new point

The reverse of inverse: from a station, with a known bearing and distance, you get the coordinates of a new point. The classic polar method of fixing a position.

Intersection — two kinds

Line–line is for two directions from two points; if they are parallel the tool says so instead of returning a number. Distance–distance (circle intersection) gives up to two solutions, so you pick the one that matches the ground.

Gons instead of degrees

A full circle is 400 gons rather than 360 degrees. If your instrument reads in gons, switch the unit at the top and both input and output stay in that measure.

Questions

Frequently asked questions

Does the COGO calculator work offline?

Yes. None of the four computations call a server — everything runs on the device.

What is the difference between inverse and radiation?

Inverse computes a bearing and distance from two known coordinates. Radiation works the other way: from a station, a bearing and a distance it returns the coordinates of a new point.

Why does circle intersection return two points?

Two circles that intersect always meet at two points, unless they are tangent. The tool shows both, and you choose the one that matches the actual position on site.

Can I compute area without a map?

Yes. The Area tab takes coordinates entered one at a time and, from the third point on, returns area and perimeter without loading a map.

Get GeoKantar

This tool ships inside the GeoKantar app. Available on the App Store and Google Play.

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