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Putting GNSS technology into perspective
Kendall James
Segment Manager Africa
Asset Collection & Management
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Leica Zeno GIS
The value in spatial information
What will this data be used for? By whom?
What important operational/economical/business decisions depend
on this information?
How important is accuracy to me?
How much time do I have?
Do I really understand what I’m doing or do I want it to be simple?
Being able to share this information and look back over time will
help me do a better job?
What is my budget?
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Positional accuracy (or quantitative accuracy)
Spatial in nature
Horizontal (distance from true location), vertical (distance from true height) and
temporal (difference from actual time and/or date)
Leica Zeno GIS
Accuracy has four legs
High accuracy
High precision
High accuracy
Low precision
Low accuracy
Low precision
Low accuracy
High precision
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Leica Zeno GIS
Accuracy has four legs
Attribute accuracy or consistency
Validity by nature
A feature in GIS is what it what it is on the ground e.g. a road on the map is a
road on the ground; a soil sample agrees with the type mapped; a planted
species is what is says in the plan
Variety N27
ID: 13.32
Var: N47
Plot: 1A
ID: 13.32
Var: N47
Plot: 1A
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Leica Zeno GIS
Accuracy has four legs
Completeness
Reliability by nature
Is everything the map claims to include in fact there
E.g. when does the road become a track
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Logical consistency
Non-spatial
Data from one area is 2001 while another is 2003
Use of different criteria or technique
Spatial
Data gaps or incompleteness
Poor topological relationships
Leica Zeno GIS
Accuracy has four legs
Sliver
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Leica Zeno GIS
Impact of differing device accuracies
CS25 GNSS Plus L1/L2 RTK 1-2cm
Area: 4341.432 m²
Zeno 5 (pole mounted)
internal antenna 2-4m
Area: 4414.946 m²
Zeno 5 w/ GG03 (pole mounted)
L1/L2 RTK 1-2cm
Area: 4411.895 m²
ArcGIS Collector app on iPhone 5S
Area: 4876.629 m²
Other handheld device
internal antenna 2-5m
Area: 4687.511 m²
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Leica Zeno GIS
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Leica Zeno GIS
Many devices to suit your needs
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Leica Zeno GIS
Thank you
Kendall James
Segment Manager Africa: Asset Collection & Management (GIS)
+27 (0)79 649 1270
www.facebook.com\leicazeno
@LeicaZenoAfrica
