User's Manual

Document Name: MARS Box User Manual
Version No: 0.2
Company Name: NextNav, LLC.
Confidential Page 9 10/24/2013
Page 9 of 9
3.2 Tune-up procedure not to exceed maximum TX power
A CSV file (configuration file) per transmitter are created by the NOC engineer based on the
installation parameters such as line lengths, antenna type etc.
The TX output power level setting is contained in the CSV file.
The output power is adjusted by the ‘attenuation’ setting. This value in the CSV file is
calculated by a formula to set the output power (not to exceed 4W EIRP). The variables used
in the calculation include PA Gain (Gpa), TX Antenna Gain (Gant), TX filter insertion loss
(ILflt), internal cable loss (ILint), external cable loss (ILext), and transceiver output power
(PTCVR).
EIRP (W) = 10^((PTCVR - ILint + Gpa - ILflt - ILext + Gant) / 10) / 1000
3.3 GPS Receive Antenna
GPS antenna should be installed such that it has clear view of sky. Ideally, you would keep the
antenna close to the ground away from obstruction
Keep any horizontal blockage smaller than 10 degrees
Obstruction Clearance guideline
If it is 1 ft wide it should be at least 6 ft away
If it is 10 ft wide, it should be at least 60 ft. away.
If it is significantly less than 1 ft wide (like a guy wire, or a post) it should not cause any
measurable effect