Navigation: Using GPS / GNSS > Averaging GPS/GNSS

## GNSS Averages Sneak Peek (3:45) -  See how to average mutliple GNSS observations in TPC and improve the accuracy of those survey points.

Example

### In the example shown here, 2 observations were made for point 201, a day apart.

G761  =761

Current Y=836622.315 X=3973572.035 Z=123.36

AVG Y=836622.372 X=3973572.026 Z=42.43 RMS Y=0.037 X=0.038 Z=0.053 PDOP=2.60 Count=352 OBS=2

G761  =761  Date/Time=03/16/23 15:03:06

OBS 1 Y=836622.315 X=3973572.036 Z=42.14 RMS Y=0.033 X=0.034 Z=0.047 PDOP=2.40 Count=51

DIFF Y=0.057  X=-0.009  Z=0.29

G761  =761  Date/Time=10/24/23 11:26:21

OBS 2 Y=836622.429 X=3973572.017 Z=42.72 RMS Y=0.041 X=0.042 Z=0.059 PDOP=2.80 Count=301

DIFF Y=-0.057  X=0.009  Z=-0.29

### The two observations are averaged to compute the position of the point, displayed as the AVG (Average).

NGS User Guidelines

In their User Guidelines, NGS says "RT positioning of important data points cannot be done reliably without some form of redundancy". They provide guidelines on how to create these redundant observations.

Specifying Redundant GNSS Observations in TPC

TPC provides a number of options for specifying redundant GNSS observations.  The method you choose will depend on your equipment (data collector), work flows and personal preferences.

Averaging GNSS Observations

TPC includes a GNSS Averages command you can use to computed the position for any GPS/GNSS point with multiple observations.

## You can reject outlying observations, generate a report of the averages and export GNSS averages to a CSV file.

Averaging GNSS Observations on Import

### TPC also looks for GNSS points with multiple observations when importing GNSS data. If it finds one or more imported points with multiple observations, it displays the GNSS Averages dialog, allowing you to reject any outlying observations, update existing survey points with the computed averages, report the averages or export them to a CSV file.

Reporting GNSS Averages

### From the GNSS Averages dialog, you can use the Summary button to report how averages are computed for GNSS survey points with multiple GNSS observations.

Exporting GNSS Averages

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