This section presents some specific aspects related to the planning of access networks to provide air navigation service such as Radar, ILS, VOR, etc.

Despite these services being commonly designed using a single transmitter instead of a network of transmitters, the planning process is based on common steps specified in the section on access network planning, although some aspects are presented here to better adapt to this kind of projects.

Then, steps of access network planning process are listed, highlighting in each of them, and when necessary, the points to which the user must pay special attention in the case of planning air navigation services.

NEEDS ANALYIS - CONFIGURATION

•Cartography. Considering that, in general, this type of services are oriented to the communication between groud and an aircraft flying at certain altitude above the sea level, the cartography to use is not a determining factor, so a terrain model with 100-meter resolution is enough.

•Calculation methods. ITU-R Rec. 528 is the method commonly used in this kind of communications. This method is based on interpolation from empirically derived basic transmission loss curves, valid for ground-air links, as functions of distance, antenna height, frequency and percentage time.

PARAMETERIZING STATIONS

•Transmitting end. It radiates the signal, in an omnidirectional way, as in the case of VOR or radar (where it is dispersed to the receiver for detection), or in a directional way, as in the case of ILS.

•Receiving end. Where, in the case of radar studies, the user can set up the target surface and searching criteria, defining a distance above sea level to create different steps to analyze (in case minimum and maximum are the same, it will be an only fixed height). For the rest of the cases, it is possible to configure the reception threshold.

NETWORK PLANNING

•Best server by signal. For radar, the user must define each step height where the target is. Multiple signal maps will be generated where each pixel represents the power level received by the transmitter considering that there is a target at the height specified by the layer. For the rest of the cases, a signal level map will be generated, taking into account the reception threshold set by the user.

•Receivers Orientation. Only in radar studies. The user must define the reception threshold to determine the minimum value where it is possible to detect a target. Therefore, the value in each pixel of this result will be the minimum height above sea level where the received signal exceeds the threshold.