GPS internals: Difference between revisions

Various properties exist under gps/config to control behaviour. They can be adjusted at any time, and depend partly on the real-world insturment being modelled, and partly on installed aircraft performance (eg, turn rate). The default values are generally acceptable.

 

- linear-deflection-nm

If positive, the cross-track error (in nm) that corresponds to full-scale CDI deflection output. Internally, this value is used to scale the cdi-deflection property, so that at is maximum value (+/- 10), it corresponds to this deviation in nm.

If this value is negative, the GPS reports angular CDI deflection (like a VOR receiver), in degrees, directly.

- min-runway-length-ft

If positive, the minimum runway length (in feet) suitable for this aircraft. This is used to filters (and airports) from search / nearest results, so that 'nearest airport' does not list close, but unusable, airports.

- hard-surface-runways-only. Flag to indicate if the GPS should consider hard-surfaced or all types of runway. Set this flag for aircraft which cannot land on soft surfaces such as grass or gravel. As above, this is used to filter search results.

- turn-rate-deg-sec - turn rate in degrees per second. Default value is 3, meaning a 180 degree turn takes one minute, which is usually called a 'standard rate turn'. This value is needed to perform accurate turn anticipation.