Viavi CellAdvisor 5G, Руководство пользователя, Страница: 45 / 359

CellAdvisor 5G User's Guide
33
▪
External - 13 MHz :
▪
External - 15 MHz :
Setting up the GPS
You can configure the GPS setting by clicking the GPS icon on the System screen. You are required to configure GPS settings if
you need the GPS location or need to use it as a frequency and clock source.
1 Select the System icon, then select GPS .
Specifying GPS settings
You can configure the settings depending on what you need but turning GNSS on and Antenna Power on should make it work for
most cases.
1 In GPS, turn on Antenna Power if required. The antenna power setting enables the external antenna power, so it depends on
what you plug into the instrument. If you have an externally powered antenna, you will not need to turn on antenna power.
2 Select the required Fix Type from the following choices:
▪
2D Mode : A 2D (two dimensional) position fix that includes only horizontal coordinates. It requires a minimum of three
visible satellites.
▪
3D Mode : A 3D (three dimensional) position fix that includes horizontal coordinates plus altitude. It requires a minimum of
four visible satellite.
▪
Any : Calculates a 3D position fix if possible but reverts to 2D position if necessary.
3 Turn the GNSS value on if using GPS.
4 Select the value representing the GNSS System supported in the region where you intend to conduct testing. If you want to use
Satellite Based Augmentation Systems (SBAS) to augment the GNSS System, select the option that provides SBAS (indicated
with + SBAS).
5 Select the desired Survey Mode from the following choices:
▪
Dynamic : Continuously calculates positioning for continuous location information
▪
Auto : Calculates positioning until accurate location information is determined and switches to fixed position using accurate
location information and switches to determine timing accuracy
6 In Elevation Limit (deg) , specify the elevation limit in degrees. This value represents the lowest point on the horizon on which
the receiver will try to locate and obtain information from GNSS satellites. The default elevation is set to 10 degrees. Using
satellites near the horizon may degrade performance.
7 In Minimum C/No (dBHz) , specify the minimum Carrier to Noise Ratio (C/ No) for the satellite signals that will be used by the
module’s GNSS receiver. The C/No is an indication of signal strength ranging from 0 to 50 dBHz. The default value is 9 dBHz.
Using satellites with a weak C/No may degrade performance.
8 Specify the Antenna Time Bias value. The default Antenna Time Bias value is 28 (the optimal value for the VIAVI qualified
antenna). If you are using a different antenna, determine the optimal bias value by referring to the vendor specifications for the
antenna (and, if applicable, splitter or amplifier), then specify the bias value in nanoseconds. This value represents the bias that
is used to compensate for the
delay introduced by your antenna, the antenna’s cable, and if applicable, an inline splitter or
amplifier where absolute accuracy of PPS is important.
Checking GPS results
In the GPS result screen, the items indicate as below:
▪
Latitude (deg) : Distance north or south of the equator measured by degrees (°) from 90° to +90°.