Introduction
Since purchasing the Trimble
GeoXH 6000 I have taken over 100 SQC’s (Standard Quality Control) from the same
datum point to test the Trimble’s precision.
During this time the Trimble’s accuracy has been tested against the
known accuracy and precision of the Leica GS15 that is jointly owned by Myrddyn
Phillips, John Barnard and Graham Jackson.
For one hour’s data collection the Leica GS15 is around +/- 0.07m (3
standard deviations) and for three hours data collection it is around +/- 0.03m
(3 standard deviations).
The comparative data sets
produced by each instrument are detailed in the Trimble / Leica – Comparison
Spreadsheet.
To see the
Trimble / Leica - Comparison Spreadsheet please click {here}
The spreadsheet consists of
the following:
Date: This is the date of
each survey conducted with the Trimble GeoXH 6000. If the summit or bwlch has been surveyed more
than once, these respective surveys are then grouped together and therefore not
listed in chronological order.
Name: This is considered the
most appropriate name of the hill. Sometimes the name used does not
correspond to current Ordnance Survey map spelling or the name may not appear on any map.
Where no appropriate name has been discovered for the hill from any source, the
Pt. (for example; Point 444m) notation is used rather than making up a name
that has no local or historical evidence of use.
1:50,000 Map: This column gives the number of the 1:50,000
Ordnance Survey Landranger map that the point surveyed appears on.
1:25,000 Map: This column gives the number
of the 1:25,000 Ordnance Survey Explorer map that the point surveyed appears
on.
Position: This column refers to
the position being surveyed, which will either be Summit or Bwlch.
Grid Reference: This is the six figure
grid reference produced by the GPS / GNSS receiver
for the point surveyed.
Trimble - Height (m): This is the processed
height in metric attained by the Trimble GeoXH 6000.
Difference (metric): This is the difference in metric between the height attained by
the Trimbe and the Leica equipment.
Leica – Height (m): This is the processed height in metric attained by the Leica GS15.
Leica – Height (m): This is the processed height in metric attained by the Leica GS15.
Trimble – Collection Time
(minutes):
This column details the total time in minutes that data were collected by the Trimble GeoXH 6000.
Leica – Collection Time
(minutes):
This column details the total time in minutes that data were collected by the Leica GS15.
Line Survey: This column details
the drop value in metric attained from a line survey (if one has taken
place). This form of survey gives the
most accurate method to determine the height gain from bwlch to summit.
Comments: The last column is
used to document any other detail of note not listed in the other columns.
To see the
Trimble / Leica - Comparison Spreadsheet please click {here}
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