LOS Survey Process Tutorial

  Survey Process consists of five basic steps;

a) Prepare the Site documentation
b) verify the Site location
c) Finding Problems in-between the path
d) Path profile
e) Overall survey report.
Site Documents
a) Site location maps to be find with Location Land Mark.
b) If it is existing site means, get site information from other customer.
Collection of details of the proposed site;
a) Observe the Absolute Mean Sea Level, height of tower, heights of antenna and angles.
b) Take photographs of site, it used for verification in future.
c) Marking of tower center from minimum three reference points
transmitters and receivers Antennae frequencies.
e) Soil samples can be taken for laboratory testing. This will be useful for economical design of the tower.
Identification of critical points along the path
a) On the maps two sites are joined by a thin straight line.
b) Determine the height, width of all obstructions along the path and HASL at each point for all potential obstructions.
c) Visit every likely critical point to ascertain its height and check other parameters.
d) Determine the width of water bodies, other reflecting points falling along the route.
e) Take mirror tests if after calculations, it is found, that, it is feasible
Generating LOS path profile;
a) It can be manually or by computerized software.
b) Hop wise data required is given below.
About hop
AMSL of each site
Hop distance (If co-ordinates are fed to computer software, you get hop distance    and azimuth angles)
HASL of each obstruction and its height including near-end obstructions, Clearance criteria being adopted. Say  Cl=k 4/3 + 100% FFZ and OR Cl=k 2/3 + 60% FFZ
Frequency band of operation.
c) With the above parameters antenna heights in each direction of operation can be worked out and hence the tower height at each sight.
Generating LOS report
a) Site Data( Height, Angle , Azimuth)
b)Any Disturbance in Path
c)Photograph about Site for Future Identification.
Detailed Survey Report
a) Determine following parameters.
Transmitter power, Size and gain of antenna’s for main and diversity, transmission line losses, Receiver threshold  Signal to noise ratio, Fade Margin
b)The complete exercise can be worked out manually with the help of a calculator or different Software’s available for Path Loss Calculations.