Taming the Survey Data "Tower of Babel"

February 6, 2008 © 2008 Mercator Land Surveying
Taming the Survey Data
“Towerof Babel”
J. R. Lemuel Morrison, PLS
Mercator Land Surveying, LLC

February 6, 2008 ©2008 Mercator Land
Taming the Tower
Objectives:
Highlight difference between the types of data
collected
Explain a framework to manage data both for
inside the office and for clients
Outcome:
Show examples using AutoCAD LDD and other
software
. . . but first an introduction. . . but first an introduction

J R Lemuel Morrison, LS
• Buckeye
• Licensed:
NJ, NY & OH
• Instructor, Land
Surveying
NYC College of
Technology
• President & Founder,
Mercator Land
Surveying

The Premise
We can take measurements in
more ways than before
There are more tools in the
surveyor’s tool box
Many more formats available
for our deliverables
Transmitting large files
becomes easier every year
– and will get easier
However, when we combine
data from different
measurement types, are the
‘hazards’ being recognized
and addressed?
However, when we deliver the
submittal to the client, do
we provide them with all
the data that might be
helpful?

Taming the Tower
Data Round UpData Round Up
ExamplesExamples
The Pitfalls of Diverse DataThe Pitfalls of Diverse Data
Data Management During DraftingData Management During Drafting
Data Collection, Analysis & ArchivingData Collection, Analysis & Archiving

Looking Under the Hood
• Will any of the data you collect be seen by
the client?
Is it direct?
Does it need to be
processed?
Does it have depth?
Is it fromothers?
Will the client see it?
Factors to considerwhen we collect data:
• How was the data collected? Was it
“touched” or obtained remotely?
• Is the data type inherently different from
each other? (angle/range, satellite,
stereoscope, astronomic)
• Do we collect more data than can be shown in
a traditional survey? Is there information that
we collected that is outside of our professional
task? (point clouds, imagery or documents)
• Are you showing data that you actually
didn’t collect but may be responsible for?

Data Round Up
Data Source Direct Process Depth
From
Others Client
Conventional Yes,
except RL
Yes, Traverse & w/GPS No No Points, no
CAD, yes
GPS – Static Yes Yes, Process & adjust
network
No No No
GPS -- RTK Yes No, only to modify base
(if needed)
No No Points, no
CAD, yes
Astronomic / Gyro n/a Yes, Process and
network adjustment
No No No
Scan Data No No Yes No Points, no
CAD, yes
Aerial Mapping No No No Yes Yes
Others (GIS, Gov,
prev surveyor,
othos)
n/a Yes, Translation /
Rotation
Yes Yes Yes
Utilities No Yes, Translation /
Rotation & Analysis
Yes Yes Orig, Maybe
CAD, yes
Deeds, Maps &
Images
n/a Yes, Analysis Yes Yes Orig, Maybe
CAD, yes

Data Roundup -- ConclusionsData Roundup -- Conclusions
Use the tools necessary to meet the client’s
need and budget.
Use the tools necessary to meet the client’s
need and budget.
Make sure the data is correct, adjusted, and
properly combined.
Make sure the data is correct, adjusted, and
properly combined.
Keep the data archived (both raw and processed),
while maintaining all the depth.
Keep the data archived (both raw and processed),
while maintaining all the depth.
Convey to the client (and others) what is required.
Also let the client know that there is additional info.
Convey to the client (and others) what is required.
Also let the client know that there is additional info.
. . . Our primary function as surveyors is to show what we find.
And to organize it and make it understandable!
The more tools you use, the
greater is the productivity and
the complexity
Data can be extremely precise, but
complete inaccurate.
You never know when you will
need the originals & losing data
during processing is a crime!
A robust product will serve the
client well and bring them back
Surveyor’s Role Comments

Outline
ExamplesExamples

Data Collection, Analysis & Archiving
Control (GPS-Static,
Traverse & Gyro)
ProcessAdjust
Deeds, Map &
Images
Aerial Mapping
Scan
Total Station
GPS-RTK
FromOthers
Utilities
Balance Import
CheckImport
RegisterClean Extract
CheckField Edit
CheckField Edit
Rectify Plot
Plot Analyze
Archive
Prepare for
CAD
Data Sources Action

Data Collection, Analysis & Archiving--
Workflow
Data Collection, Analysis & Archiving--
Workflow
Total
Station
Deeds &
Maps
Utilities Others
Aerial
Mapping
Scan
GPS RTK
Final
Product
From this point forward I will
focus on the CADMapping
process to create the final
product
Direct
Process (for another session)
Depth
From Others
Client
From this point forward I will
focus on the CADMapping
process to create the final
product
Direct
Process (for another session)
Depth
From Others
Client

Outline
ExamplesExamples
Not all data is
created equal

Pitfalls of Diverse Data
More ‘hazards’ lie in combining this dataMore ‘hazards’ lie in combining this data
Deeds &
Maps
Utilities
Others
Aerial
Mapping
Scan
GPS RTK
Total
Station
Final
Product
Data is familiar, but the quality is not apparent
Good quality “looks” the same as poorquality
Point data is overwhelming --
extracted points are too exact; e.g. can’t tell what
type of MHit is.
Elevations are suspect. All data is
remotely collected.
Provenance of data is unclear
Quality and breadth is unclear. Lots
of non-survey info.
Deeds, maps & images: lots of non-survey
data.

Outline
ExamplesExamples
Data Collection, Analysis & ArchivingData Collection, Analysis & Archiving Background &
Review
OurProcess

Typical Solution Process
Foresight, leadership,
and decisiveness.
Deliberation and clear
implementation.
Followed by

Mercator’s Data Management Process
Given:
1) All data is not created
equal . . .
2) Not everyone may know
that there are differences
(orcare).
3) Typical heavy workload
makes good communication
unlikely
When viewed in CAD, the
difference among data
(namely points) should be
self evident
When viewed in CAD, the
difference among data
(namely points) should be
self evident
Workflow
Visuals
The result:
Showing what we find in a clear and easily understandable manner
The result:
Showing what we find in a clear and easily understandable manner
Critical Point:
Two Methods Governing Data Management

Framework -- Tools
When looking for ways to manage the mess, I
try to remember a lesson that I have a hard
time following:
KI S S
For inside the office process, I look to existing tools:
Field Codes
Layers
xreferences
Nothing new. However . . . a wish:
Easy metadata software to manage our survey data (quality, source, etc.)
Nothing new. However . . . a wish:
Easy metadata software to manage our survey data (quality, source, etc.)
Point Groups
ForClients:
File Folders
Thumbnail Viewers
Point Cloud Viewers

Management – Collected Data
Codes are applied
Points are given a style
Points are grouped
Points are modified as they are imported into the CADenvironment
Typical workflow after we process pointsTypical workflow after we process points
Software modifies the point description, moves points into a
layer& inserts a symbol with a point.
Fordirect points, staff sets a large node and uses vivid
colors. Forindirect points, staff sets a small node and
uses subdued colors.
Software groups the points by date and by type (e.g. scan
orRTK)

Management -- Collected Data
Control (GPS-Static,
Traverse & Gyro)
Deeds, Map &
Images
Aerial Mapping
Scan
Total Station
GPS-RTK
Others
Utilities
W-- Create Report
V -- Lockpoints in CAD
Generally not submitted & only
referenced during CAD
Similar in their limitations
A separate category
W- Workflow V – Visual
Similar in their limitations
A separate category
Crucial frameworkdata, but control is not used much in the drafting process
These are a surveyor’s primary measurements.These are a surveyor’s primary measurements.

Total Station
GPS-RTK
W-- use codes & many layers
V -- Text EL60; Point node shown
with a size respective to scale
Workflow and appearance are
conventionally the same
“Vf” for Survey - Field
W-- use same codes but with
an ”R” prefix
V -- shown as regularpoints
Reflectorless
Workflow and appearance are the same.
Points are in a different layer
“Vd” forSurvey-Digital
W-- use same codes
V – shown as regularpoints
W-- Points are exported with a PNEZDQ
format. Points w/unacceptable or poor quality
have a the text ‘NGCQ’ added to the code.
V – shown as regular points
Workflow and appearance are the
same, but quality needs to monitored
and noted.
“Vf” forSurvey - Field
Quality
Workflow and appearance are the
same, poorquality is flagged
“Vf” forSurvey - Field

Scan -- High-Definition Survey
Extracted
Points
W-- points are exported with “R”
codes.
V -- Text & Node shown at ¼
size; colors are subdued
Workflow is similar. Appearance
makes drafting easier and
clarifies the type of data.
“Vd” for Survey - Digital
Entities
Workflow is different and still
evolving.
“Vd” for Survey - Digital
W– Draw and then export for point cloud
software. Store in a “recycle” directory.
Insert into CADand modify.
V -- colorand layerare created by point-
cloud software and then renamed in CAD
once the entity has been reviewed.

Codes are applied
Points are given a style
Points are grouped
Points are modified as they are imported into the CADenvironment
Typical workflow after we process pointsTypical workflow after we process points
Software modifies the point description, moves points into a
layer& inserts a symbol with a point.
Fordirect points, staff sets a large node and uses vivid
colors. Forindirect points, staff sets a small node and
uses subdued colors.
Software groups points by date and by type (e.g. scan or
RTK)
Simple tools to organize data --
makes the origin and nature of the points self-evident.
Simple tools to organize data --
makes the origin and nature of the points self-evident.

Management – Data from Others
Data fromOthers
Aerial Mapping W-- Keep aerial mapping in its own drawing and
use as an xreference. Field edits go into a new
drawing. Staff moves revised items into a
redundant layer that does not plot.
‘<<layer name >>-R’
V -- use ourline types & line weights.
Redundant layer is visible but shown with a dark
brown colorto signify that it has been changed.
Workflow keeps the aerial
mapping as a separate drawing.
Modified items are not deleted,
but are shown with a subdued
color
Adjacent Survey
GIS
Orthophotography
W-- Keep other workin its own
drawing and use an xreference. Use
XCLIPto hide areas not needed.
V -- change colors and line types
through the xreference, as needed.
Workflow keeps the data by
others in a separate file.
Appearance can be changed
without changing the original
Other disciplines

Management – Records
Deeds, Map &
Images
Utilities
W-- Keep scanned document and analysis
in its own drawing. It is not shared with the
client.
Export only lines that are needed and have
been reviewed. Insert these lines into a new
drawing.
V -- change colors and line types as needed
Workflow keeps the documents and analysis
internal.
Only the workthat has been reviewed is prepared
and provided to the client
Appearance follows a company (orother)
standard.
All line workis drawn on a
“Vd” layer Survey-Digital

Management – DepthManagement – Depth
What does depth mean?
What surveyors collect often has value to the
client and allied professionals that is outside
of a surveyor’s perspective.
Don’t forget about it; share it.
A plan-view survey is limited in showing additional
information (the depth) to the client.

Management – DepthManagement – Depth
Point CloudsPoint Clouds
Utility RecordsUtility Records
Deeds, Map &
Images
Deeds, Map &
Images
Provide clients with a point cloud vieweror
provide segment of the point clouds
Provide clients with digital image of all records
Add a references to collected documents
Provide clients with digital image of all records
Create thumbnail galleries
Data Sources That
Have Depth
How to Show Depth

Outline
ExamplesExamples
Pitfalls of Diverse DataPitfalls of Diverse Data

Layers and Codes
Use a Robust Layering Scheme
Use an existing framework such as:
Discipline -Majo r-Mino r-Ite m -Entity
V is the discipline for Survey
Vf = for direct measurement
Vd = digital and non-direct
Va = aerial mapping
Major – Road, Util, Site, etc.
Minor – Curb, Gas, Ground, etc.
Desc – MH, Valve, Depressed curb
Entities
G- Geometry (lines, circle, etc.)
S – Symbols
T – Text & annotation
H – Hatching
P – Points
R – Redundant Data

Examples -- Layers

Examples -- Codes

Appearance of Points
This is ourstandard format and
common to most firms
When combining conventional
and scan points, the screen
gets too cluttered and
becomes unclear.
We import scan points with a different
style than conventional points.
I preferan absolute size. A relative
size can also be used

Scan Points in AutoCAD

Point Groups
Point Group is a simple tool
customarily used to put together
similarpoints (e.g. trav, check&
existing ground).
It’s good practice to create a group
foreach day that survey workis
imported. That is a date group.
Additionally, we add a designation to
the date group name: such as ‘RTK’
and ‘scan’ points.

Points -- Quality
Using GPS in RTKis a fantastic
productivity tool. Quality must be
monitored continually.
As points are collected good and poor
quality points are generated.
Sometimes you can use the good, the
bad and the ugly (e.g. wetlands).
Most times you can’t.
When the ugly is used in combination
with others, how should the CADuser
be alerted to the nature of the points?
Add ‘NGCQ’ in the notes during the
field collection.
Checkquality when exporting from
GPS software

Points -- Quality

Files from Others
When we use files that were
generated by others (namely aerial
mapping), I like to keep the file in its
original and unchanged state.
Revised entities are moved to a
redundant layer. The layerhas a
subdued color.
Ouradditions are in a separate CADfile
that is xreferenced along with the
original aerial mapping drawing.
The redundant layeris non-plottable.

Xreferences

Depth: Digital Documents
In the digital age, many of the files
we collect can now be easily shared.
(and should be!)
We organize the files so that the
client (and ourteam) can readily find
data.
We also create thumbnail galleries
forthe client. This makes navigation
and finding important images
intuitive and easier.

Depth: Point Clouds
3-Dscanning is a good tool to remotely
collect a fantastic amount of data.
The software formanipulating point
clouds is expensive and hard to use.
The database is enormous and has little
meaning in plan view.
Are there otherformats?
The viewerhas limited functionality, but gives
the client a way to access the data. and to
answerquestions forthemselves!
Animations are cool & sexy. Otherthan the
gee-whiz factor, there is nothing
substantive forthe client.
One option is to provide the client
with a viewer to access the scan.
One option is to provide the client
with a viewer to access the scan.
However, almost of all of it is discarded
and not used forthe client.

ConclusionConclusion
CodesCodes
LayersLayers
xreferencexreference
Digital DeliverablesDigital Deliverables
Point GroupsPoint Groups
Here’s the concluding point:
Show what you find:
the good, the bad and the ugly.
Here’s the concluding point:
Show what you find:
the good, the bad and the ugly.
Tools
If we don’t:
We are missing our rightful place
in the information age: .
If we don’t:
We are missing our rightful place
in the information age: .

ThankYou
Lem Morrison
lmorrison@mercatorgroup.com
646 837 0780
Lem Morrison
lmorrison@mercatorgroup.com
646 837 0780

Taming the Survey Data "Tower of Babel"

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