1 1

Amy Anderson

Katie Lima

Melissa Pierce

August 4, 2013

Comparing Trail Mapping

Approaches

2 2

Content

Proposal review

Adjustments to project

Data dictionary

Methodology flow charts

Precision comparison maps

Advantages and disadvantages of technology

Comparison table

Assessment of project

Lessons learned

Sources

3

What are the advantages and disadvantages of using

different technology for deriving trail maps?

Recapitulate Original Proposal

Figure 1: Study area and trail

USC Wrigley Institute

Pacific Ocean

Catalina Island

Deer Valley Trail

4

- Order of project

- Digitization interface

- Adjusted data focus

Adjustments to Original Proposal

Figure 2: iOS data collection at trail head

5

Google Earth Trimble Juno 3B iOS MotionX app

create/test data dictionary

send data dictionary to device

set parameters set parameters set parameters

digitize path collect data (x,y, not z) collect data (x,y, not z)

send field data file to pathfinder

differential correct

export as kml export .cor to ArcGis shape file share gpx file via email

convert gpx to features

convert KML to layer import to ArcMap convert points to line

2 Maps: 3 lines + 1 polygon 2 Maps: 3 lines + 1 polygon 2 Maps: 3 lines + 1 polygon

Lin

es

Feat

ure

to

Po

lygo

n

1. Assess study area

2. Collect data 3 times for each method described below

3. Compare and analyze data created:

Pre

-Co

lle

ctio

nD

evi

ce W

ork

Arc

Map

SHP SHP

⌂ ⌂ ⌂

SHP SHP SHP SHPlyr lyr lyr

KML KML KML GPX GPX GPX

Each gray box represents 1 map

M

E

T

H

O

D

O

L

O

G

Y

Figure 3: Methodology chart

6

Google Earth Trimble Juno 3B iOS MotionX app

create/test data dictionary

send data dictionary to device

set parameters set parameters set parameters

digitize path collect data (x,y, not z) collect data (x,y, not z)

send field data file to pathfinder

differential correct

export as kml export .cor to ArcGis shape file share gpx file via email

convert gpx to features

convert KML to layer import to ArcMap convert points to line

2 Maps: 3 lines + 1 polygon 2 Maps: 3 lines + 1 polygon 2 Maps: 3 lines + 1 polygon

Lin

es

Feat

ure

to

Po

lygo

n

1. Assess study area

2. Collect data 3 times for each method described below

3. Compare and analyze data created:

Pre

-Co

lle

ctio

nD

evi

ce W

ork

Arc

Map

SHP SHP

⌂ ⌂ ⌂

SHP SHP SHP SHPlyr lyr lyr

KML KML KML GPX GPX GPX

Each gray box represents 1 map

M

E

T

H

O

D

O

L

O

G

Y

Feature to polygon example

7

Results: Google Earth Digitization

Polygon area: 73,628.93 sq. ft. Figure 4: GE precision comparison

8

Advantages of GE Digitization

- Inexpensive

- Can be used by an inexperienced data collector

- Little preparation and processing

- Does not require ground truth

- Not time consuming

Disadvantages of GE Digitization

- Not as precise as other technology

- Digitization accuracy will depend date of imagery

- Minimal attribute editing ability

- Accuracy unknown

9

Google Earth Trimble Juno 3B iOS MotionX app

create/test data dictionary

send data dictionary to device

set parameters set parameters set parameters

digitize path collect data (x,y, not z) collect data (x,y, not z)

send field data file to pathfinder

differential correct

export as kml export .cor to ArcGis shape file share gpx file via email

convert gpx to features

convert KML to layer import to ArcMap convert points to line

2 Maps: 3 lines + 1 polygon 2 Maps: 3 lines + 1 polygon 2 Maps: 3 lines + 1 polygon

Lin

es

Feat

ure

to

Po

lygo

n

1. Assess study area

2. Collect data 3 times for each method described below

3. Compare and analyze data created:

Pre

-Co

lle

ctio

nD

evi

ce W

ork

Arc

Map

SHP SHP

⌂ ⌂ ⌂

SHP SHP SHP SHPlyr lyr lyr

KML KML KML GPX GPX GPX

Each gray box represents 1 map

M

E

T

H

O

D

O

L

O

G

Y

10

Data Dictionary

Trail (Line) Log Interval: 1 Second Offset: 0

Comment Length 100

Date of Collection MDY format Auto Generate on Creation

Time of Collection 24 hour format Auto Generate on Creation

Hazard (Point)

Type of Hazard Rock Cactus Tree Branch Tree Root Other

Photo

Action Needed? Yes No

Comment Length 100

Date of Collection MDY format Auto Generate on Creation

Time of Collection MDY format Auto Generate on Creation

Trail Sign (Point)

Sign Subject Length 100

Photo

Comment Length 100

Date of Collection MDY format Auto Generate on Creation

Time of Collection 24 hour format Auto Generate on Creation

If Yes…

Comment Length 100

Figure 5: Trimble Juno 3B

11

Parameters

WHAT IS A HAZARD? • Blocks 1/3 of the trail

• Sticks up jagged out of ground any items that could easily trip a person

• Any part of a cactus over any part of the trail

• Anything hanging six feet or lower over the top of the trail

• ‘Other’ is up to your discretion

Figures 6-10: Root, multiple hazards, rock, cactus, tree branch

12

Results: Trimble Juno 3B

Polygon area: 11,598.87 sq. ft.

Figure 11: Trimble Juno precision comparison

13

- Highly accurate and precise

- Reliable in field

- Files can be manipulated

- Attributes of features easily collected

- Relatively lengthy set-up processing time

- Requires several components

- Must upload imagery

- Not intuitive

- Expensive

Advantages of Trimble Juno 3B

Disadvantages of Trimble Juno 3B

14

Google Earth Trimble Juno 3B iOS MotionX app

create/test data dictionary

send data dictionary to device

set parameters set parameters set parameters

digitize path collect data (x,y, not z) collect data (x,y, not z)

send field data file to pathfinder

differential correct

export as kml export .cor to ArcGis shape file share gpx file via email

convert gpx to features

convert KML to layer import to ArcMap convert points to line

2 Maps: 3 lines + 1 polygon 2 Maps: 3 lines + 1 polygon 2 Maps: 3 lines + 1 polygon

Lin

es

Feat

ure

to

Po

lygo

n

1. Assess study area

2. Collect data 3 times for each method described below

3. Compare and analyze data created:

Pre

-Co

lle

ctio

nD

evi

ce W

ork

Arc

Map

SHP SHP

⌂ ⌂ ⌂

SHP SHP SHP SHPlyr lyr lyr

KML KML KML GPX GPX GPX

Each gray box represents 1 map

M

E

T

H

O

D

O

L

O

G

Y

15

Results: iOS

Polygon area: 66,520.12 sq. ft.

Figure 12: iOS precision comparison

16

- Limited attribute collection and manipulation

- Temperamental application

- Unreliable if cellphone coverage is spotty

- Not intuitive

- Wide range of accuracy

- Storage problem

Advantages of iOS

Disadvantages of iOS

- Relatively inexpensive

- Minimal processing time

- Yields clearer photos

17

Results Map: Three Technical Devices

Figure 13: polygon comparison of three technologies

GE 73,628.93 sq. ft. Trimble 11,598.87 sq. ft. iOS 66,520.12 sq. ft.

18

Google Earth Trimble Juno

3B

iOS MotionX

appSetup time L K

Time to digitize / collect data L K

Postprocessing time L K

Total Time (in hours) K L

Equipment / software needed L K

Accuracy of device n/a K

Field Reliability n/a L

File Manipulability L K

Precision (based on calculated area) L K

Access of imagery base maps L K

Photo capabilities n/a K

Ground level data attribute collection capabilities L K

Skill to use (Novice vs. Expert) L L

CO

ST

Associated costs L K

5 5 3

K 1 2 9

L 4 6 1

n/a 3 - -

TIM

ETE

CH

NO

LOG

YU

SAB

ILIT

Y

Table: Advantages/Disadvantages of Technology

Figure 14: comparison of three technologies

19

What worked well?

- Team cohesion

- Completed data collection with two days to spare

- Lack of tree coverage, favorable terrain and weather

- Used other teams as a resource

- Conducted pilot tests of the trail and devices

What did not work well?

- Initial interface for digitization

- Importing, differential correcting, projecting

- MotionX GPS service

20

- Each method has merit in certain situations

- Visualization tools can easily illustrate precision

without complicated formulas

- Planning and pilots are key

Take Always

21

Sources

Brown, Kevin. “GPS/GIS Workshop.” USC GPS/GIS Field Exercise. USC Wrigley Institute, Catalina Island,

CA. 30 July 2013. Workshop.

Esri. ArcGIS Resources. “Feature to Polygon” and “Projection.” help.arcgis.com/en/arcgisonline/help/. 7 July

2013. Web. 1 August 2013.

Esri, DeLorme, NAVTEQ © 2013. ArcMap Service Credit Layers. Web. 2 August 2013.

Fullpower Technologies, Inc. 2013. MotionX-GPS. http://www.motionx.com/.

Google Earth. Google Earth application. http://www.google.com/earth/index.html. Web. 31 July 2013.

Trimble. “Juno 3 Series Handhelds.” http://www.trimble.com/mappingGIS/juno3.aspx?dtID=applications&.

30 July 2010. Web. 2 August 2013.

22

Conclusion

QUESTIONS?

Melissa Pierce: piercem@usc.edu Amy Anderson: bartlow@usc.edu Katie Lima: katielim@usc.edu