## Wndsn Telemeter Introduction

*Idea and principle.*

A tool for makeshift navigation, surveying, and rangefinding, the flagship Wndsn Telemeter enables you to do more than merely guessing distances. Find an object of known size at the distance you need to measure and let the baked in trigonometry do the rest for you; all by aligning the provided string across the scales.

## The principle

The distance from eye to measured object, and the height of the measured object, form two sides of a right triangle, and thus determine an angle:

`D = S * d / s`

where `D`

is the distance to the object, `S`

is the size of the object observed, `d`

is the distance from the measurement device to the observer's eye, and `s`

is the apparent size of the object observed.

We are making use of trigonometry to determine the relationships between values we have, values we are able to measure, and the values we need to calculate.

### Telemeter?

The word *Telemetry* is derived from Greek roots: tele = remote, and metron = measure; and we do exactly that; measuring from afar.

A telemeter is a device used to remotely measure any quantity. It consists of a sensor, a transmission path, and a display, recording, or control device. Telemeters are the physical devices used in telemetry. Electronic devices are widely used in telemetry and can be wireless or hard-wired, analog or digital. Other technologies are also possible, such as mechanical, hydraulic and optical. (Wikipedia)

For our distance measuring instruments, for mission-critical durability and reliability, we prefer the analog and graphical kind of telemetry.