Line-of-Sight (LoS) survey is the first and most crucial milestone in any microwave link project.

LoS is an integral part of Link Design and the accuracy of the data collected during this stage is vital to the operating performance of the link. Line-of-Sight Surveys must be conducted by specially trained and equipped personnel.

A line-of-sight report must be prepared for every proposed microwave link and provide the following information as a minimum:

• Information on both ends points of the link (site ID's, names, co-ordinates, heights for existing towers, address and/or location details, photos)
• LoS result (such as Yes/No/Not recommended, Good/Bad/Marginal)
• Recommended antenna heights and/or locations for both ends
• Whether the antenna heights include Fresnel zone clearance and if they do, clearance criteria used for the calculation
• Proposed antenna locations on existing towers or rooftop sites
• Whether there are reflective surfaces on path and their description ( such as "lake between 5.5 and 7.2 km" or "flat paddocks on entire path that can be reflective when wet")
• LoS photos; typically one wideangle and one zoom
• Path profile, if required by client
• Any other information that may be relevant to link design and site acquisition, such as possible future obstructions