---
name: "fgelev"
section: "1"
platform: "linux"
package: "flightgear"
version: "1:2020.3.19+dfsg-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/fgelev"
---

# fgelev(1)

Compute FlightGear scenery elevation for a given list of points

## NAME

fgelev - Compute FlightGear scenery elevation for a given list of points

## SYNOPSIS

**fgelev** \[**--expire** *num*\] \[**--print-solidness**\] \[**--fg-root** *rootdir*\] \[**--fg-scenery** *scenerydir*\]

## DESCRIPTION

**fgelev** is a standalone utility that, given a list of points on standard input, prints the corresponding elevation for each of them on standard output. It can also (optionally) print whether the material covering that point is solid or not.

The list of points must be in the following form:

    *id lon lat*

where *id* is an arbitrary identifier for the point, *lon* is the longitude of the point and *lat* is the latitude of the point. Positive longitudes (latitudes) correspond to points located in the Eastern (Northern) hemisphere; negative ones correspond to points located in the Western (Southern) hemisphere.

The list of elevations returned by **fgelev** is in the following form:

    *id: elev solid*

where *id* is the identifier of the point passed as input, *elev* is the elevation of the point in meters (or **-1000** if the elevation of the given point was not found) and *solid* is:

- •

  the string **solid** if the parameter **--print-solidness** was passed to **fgelev** and the material covering the point is solid;

- •

  the string **-** if the parameter **--print-solidness** was passed to **fgelev** and the material covering the point is not solid;

- •

  absent if the parameter **--print-solidness** was not passed to **fgelev**.

## OPTIONS

- **--expire** *num*

  To speed up elevation data retrieval, **fgelev** uses an internal cache. This option lets the user specify the number of requests after which, if a point was not queried in them, it should be marked as expired. By default, **fgelev** expires points not queried in the last **10** requests.

- **--print-solidness**

  Require **fgelev** to print the solidness of the material covering the queried point. See the **DESCRIPTION** section for more details.

- **--fg-root** *rootdir*

  Set the FlightGear data root directory (**$FG\_ROOT**) to *rootdir*. If this option is not set, **fgelev** uses the path specified in the **FG\_ROOT** environment variable or, absent that, the FlightGear data directory chosen at the time the program was compiled.

- **--fg-scenery** *scenerydir*

  Set the FlightGear scenery directory (**$FG\_SCENERY**) to *scenerydir*. If this option is not set, **fgelev** uses the path specified in the **FG\_SCENERY** environment variable or, absent that, the **Scenery** subdirectory inside **$FG\_ROOT**.

## EXIT STATUS

**fgelev** exits with **EXIT\_SUCCESS** on success, with **EXIT\_FAILURE** if it is unable to read data from standard input or to load the scenery.

## ENVIRONMENT

- **FG\_ROOT**

  If **FG\_ROOT** is set and **--fg-root** is not set, it specifies the root data directory to use.

- **FG\_SCENERY**

  If **FG\_SCENERY** is set and **--fg-scenery** is not set, it specifies the scenery directory to use.

## SEE ALSO

[**fgfs**(1)](/fgfs/1.md)