How to set your working height

Wind speed is not constant at all levels above the ground, and it typically increases with height. For crane operation, drone flight or spraying, the conditions at your own working height matter. A ground-level reading would misrepresent work at 50 metres. The instrument works out the modelled wind speed and direction at the height you specify, which is more relevant than a 10 m figure. It is still a forecast, not a measurement. You can read more in Why the number changes with height.

On the main instrument page (/app) the Height control sits in the top bar. It is a stepper with minus and plus buttons, and you can also type into the box. On a phone-sized screen the same control is repeated inside the inspector panel. The allowed range is 2 to 300 metres, and each button press moves the height by 5 metres, so from the default 10 m you step to 15 m, then 20 m. Typing is not limited to steps of five: a value such as 45 is accepted, and anything outside the range is pulled back to the nearest limit. The height is remembered on this device along with your last place, limit, unit and persona.

The instrument uses model wind at four native levels: 10, 80, 120 and 180 metres. At exactly one of those heights, the fidelity reads Native model level. For any other height between 10 and 180 metres, the instrument interpolates on a logarithmic height scale between the levels above and below, reported as Interpolated between native levels (log-height). Below 10 metres or above 180 metres it extrapolates with a neutral log law and a surface roughness of 0.03 m, labelled EXTRAPOLATED. The agreement spine tick named Height fidelity is more forgiving: it holds within 10 m of a model level, turns hollow when you are further away, and fails when the height is extrapolated or unknown.

Example: a crane supervisor with a jib at 45 metres sets the Height to 45 m, and the instrument interpolates between the 10 m and 80 m levels. You can learn more in Height-matched wind for cranes. Example: a drone pilot at 100 metres sets 100 m, interpolated between the 80 m and 120 m levels. Example: a spray contractor with a boom 2 metres off the ground types 2. That is below the 10 m level, so the value is extrapolated.

If you set a Height below 10 metres or above 180 metres, the instrument extrapolates from the nearest model level. The fidelity text then reads EXTRAPOLATED with the log law note, the Height fidelity tick on the agreement spine fails, and the agent may point out that the height is extrapolated. Extrapolated values are less precise than native or interpolated ones, so treat them with extra caution. The neutral log law assumes open, level ground and does not account for buildings, trees or stability. You can read more in Log law wind profile.

Each persona preset in the top bar sets a starting Height: Crane 80 m, Drone 120 m, Wind ops 120 m, and Spray, Marine, Golf, Motorsport and Event 10 m. Choosing a persona overwrites your current height, unit and limit with the preset's values, so pick the persona first and adjust the height afterwards. Saved sites keep their own working height, which you enter in the Add site panel on your account page (1 to 500 m, starting from the persona height). Opening a saved site from that page loads the instrument with that height. The height on screen is not copied into a saved site automatically. See Save your first site.