PDOP column

[routeconverter]

Is there any means to calculate an accuracy in terms of distance based on any of those DOP values?

Is PDOP the only value that you get from your device?

The Columbus 9xx, GPX and NMEA formats contain fields for PDOP, HDOP, PDOP but not GDOP or TDOP which would be more interesting if I understand the page that Alf Onico found correctly:

GDOP : Geometrical Dilution of Precision, (measure of accuracy in 3-D position and time)
PDOP : Position Dilution of Precision (measure of accuracy in 3-D position), also called spherical DOP
HDOP : Horizontal Dilution of Precision (measure of accuracy in 2-D position, for example Latitude and Longitude)
VDOP : Vertical Dilution of Precision (measure of accuracy in 1-D position, Height)
TDOP : Time Dilution of Precision (measure of accuracy in Time)

One could the PDOP values into classes with a descriptive name like the Wikipedia article suggests:

Code:

Value    Rating     
1        Ideal     
1-2      Excellent         
2-5      Good     
5-10     Moderate     
10-20    Fair         
>20      Poor

This page claims rather the same

A low PDOP is better. A PDOP of 4 to 6 is considered good. Position solutions calculated when the PDOP is from 6 to 10 should be used cautiously because they may have significant error. A PDOP that is above 10 indicates unacceptable error. The ICAO (International Civil Aviation Organization) states that a PDOP of less than 6 is required for en route navigation, with a PDOP of 3 or less required for nonprecision approaches [i.e., not ILS (instrument landing system) types].

So would about having a column "Signal Quality (PDOP)" filled with values "Good (3)", "Moderate (5)", "Ideal (1)"?