Map Viewing Service (WMS) of the dataset: Areas and Areas of Release linked to easements PT2 (Radio Reception Centres) in Eure-et-Loir (28) as of April 15, 2021

The attitude of an easement is the spatial field (i.e., the geographical area) within which the easement applies. This spatial field may be defined either in 2D or in 3D in particular in the particular cases of clearance easements at airports, easements for the protection of radio transmission centres.The attitude shall include primary clearance zones, secondary clearance zones, special clearance zones and clearance areas.The maximum distance separating the limit of a radio station and the perimeter of the easement areas may not exceed:- 2 000 metres in the case of a secondary clearance zone;- 400 metres in the case of a primary clearance zone surrounding an aeronautical safety facility or a radio-gonometric centre;- 200 metres in the case of a radio area not exceeding a maximum area of clearance. In practice, the beam shall be assimilated to a band and the attitude shall not exceed 50 m on either side of the axis.The maximum width of a clearance area protecting a radio tracking or navigation station may not exceed the width of the angular area explored by the station, increased, where appropriate, by a safety margin of not more than one degree beyond the two limits of that area.地役权（easement）的适用幅限空间场域（即地理范围），是地役权得以适用的空间区域。该空间场域可采用二维或三维方式界定，尤其适用于机场净空地役权（clearance easement）、无线电传输中心保护地役权等特定场景。该适用幅限应包含一级净空区、二级净空区、特种净空区以及净空区域。无线电发射台站边界与地役权区域周长之间的最大间距不得超过以下限值：- 二级净空区情形下为2000米；- 环绕航空安全设施或无线电测向中心（radio-gonometric centre）的一级净空区情形下为400米；- 净空面积不超过最大许可净空面积的无线电区域情形下为200米。实际应用中，波束应被类比为带状区域，且该适用幅限在轴线两侧的延伸范围均不得超过50米。保护无线电跟踪或导航站的净空区域的最大宽度，不得超过该台站探测的角域范围宽度；若有必要，可在该区域的两个边界外额外增加不超过1度的安全裕度。