Mapping with GPS/integrating location based

information with GIS databases

Agenda

GPS Data CollectionCensus Mapping with TrimbleGPS Data MaintenanceSummary

GPS Segments

ControlSegment

Monitor Stations

User Segment

Space Segment

ControlSegment

<20 m

Standard Positioning Service - Autonomous GPS

<12 m

Precise Positioning Service-PPS P(Y) Code GPS

<2m

Base Station

Mapping Grade Receiver-DGPS

<1mBase Station

High Quality Mapping Receiver SPS-DGPS

<1cm

RTK Base Station

Real-Time Kinematic Surveying

<1/2 cm

Base Station

Survey Grade GPS

20 m2m

1m12m

1/2cm

1cm

Where Do You Need to Be?

50 m2m

1m12m

1/2cm

1cm

Real-Time or Postprocessed?

Examples of Different Accuracy Requirements

Code Phase GPS40 m - Navigation at sea10 m - Navigation to section corners2 m - Rural GIS data capture1 m - GIS data collection in urban area

Carrier Phase GPS1 cm - Stake out½ cm - Control Surveys

Differential Correction

Base Station generates corrections for all satellites in view

Roving GPS receiver uses corrections to reduce errors

Differential correction can be performed in either real-time or postprocessed mode

BASE

Time, t

t + 1GPS Positions

Absolute ReferencePosition

Differential Correction (Simplified)

If you collect data at one location, there will be errors

Each of these errors are tagged with GPS time

ROVER

Time, t

t + 1

?

Differential Correction (Cont.) At the same time, the

errors occurring at one location are occurring everywhere within the same vicinity

Satellites Seen1 2 3 4 5 6 7 8

Satellites Used1 2 3 41 3 5 6Any Combination of Base satellites

ROVER

Time, t

t + 1

?BASE

Time, t

t + 1

Differential Correction (Cont.)

Example of Uncorrected File

Example of Corrected File

Base Station: 15° Rover: 15°

Poor Situation – Satellite visible to Rover only. Base Station is not tracking it.

Possible Problem...

setting the elevation masks

1° per 100 km distance between base and rover

Base Station: 10° Rover: 15°

Ideal Situation – Satellite is being tracked by both Rover and Base Station.

Solution...

Set base elevation mask less than rover

Why GPS ? Satellite-based.Digital CoordinatesFast & Acceptable AccuracyEasy integration with Most GIS SoftwareMore suitable for extended application of GIS

e.g. Census Data Analysis Emergency Services Location Based Services Disaster Management Asset Management

GPS Data Collection

Collection of Geographic Data (GI) Points, Lines, Areas Offset locations 1 to 5 meter precision

Customized attributeinformation

Menu lists, Text, Numeric, Dates and times Multiple data dictionary support Infield data dictionary creation

2. Census Mapping with Trimble

Trimble Mapping is High-end Mapping Grade Receiver to be used for

Recording something, somewhere (What do I have?)

Navigation Finding something, somewhere (Where is

it?) Updating

Verifying something, somewhere.

(Is the information I have correct?)

Juno ST GPS Handheld

Stylus holder Headset connector

Reset button

GPS antenna connector

Power button

Lock switch

Power/USB socket

SD card slot

Directional button

Contacts

MessagingToday screen

Calendar

Performance Postprocessing

Improve the overall quality and consistency of your data by postprocessing …

Juno ST AutonomousHRMS 2.11mBias 0.63mWorst 5.6m

Juno ST PostprocessedHRMS 1.12mBias 0.55mWorst 4.6m

Recon XC GPS Receiver The GPS Pathfinder® XC receiver is totally enclosed beneath the

extended CF-Cap™ No receiver or antenna cables to snag or break Plug and play with CompactFlash

Achieve 2 to 5 meter postprocessed accuracy Requires field software capable of logging data

for postprocessing TerraSync™ software ArcPad with the Trimble GPScorrect ™ extension Applications created with the GPS Pathfinder

Tools Software Development Kit SDK Also requires office processing software

GPS Pathfinder Office software Trimble GPS Analyst ™ extension for ESRI

ArcGIS software

Rugged and weatherproof IP 67

Sand and dust: MIL-STD-810F, Method 510.4, Procedures I and II

Water: MIL-STD-810F, Method 512.4, Procedure I (submersion in 1 meter of water for 30 minutes)

Wide operating temperature range –10 °C to 50 °C (14 °F to 122 °F)

Drop specification 4 ft (1.22 m) MIL-STD-810F, Method 516.5, Procedure IV

Vibration resistant MIL-STD-810F, Method 514.5

Trimble Recon GPS XB edition Affordable

Equip your entire mobile workforce

Reliable 2 to 5 meter accuracy Using SBAS or

postprocessing Rugged field computer Cable-free

Bluetooth® wireless technology connection to GPS Pathfinder® XB receiver

Choice of field software

Compared withTrimble Recon GPS XC edition

Trimble Recon GPS XB edition

Trimble Recon GPS XC edition

Built-in Bluetooth wireless technology

No built-in wireless

External GPS receiver Internal GPS receiver

SBAS for real-time 2 to 5 meter DGPS accuracy

Can also post-process

No SBAS

Use post-processing to achieve 2 to 5 meter accuracy

Trimble Recon handheld Key Features

Ultra-rugged and lightweight IP 67

Integrated wireless options Optional built-in Bluetooth® wireless

technology and wireless LAN Range of systems to best meet your needs

Select from 3 different Trimble Recon handheld systems

GPS functionality easily added TrimPix™ technology wireless camera

support

GeoExplorer 2005 series Three models: three levels of accuracy

GeoXH™ handheld—Subfoot (with H-Star™ technology) GeoXT™ handheld—Submeter GeoXM™ handheld—1–3 m

Microsoft® Windows Mobile® version 5.0 software Maximum flexibility in software choice

512 MB onboard storage plus removable SD card storage

Bluetooth® and 802.11b Wireless LAN connectivity options Rugged handheld with all day battery TrimPix™ technology for wireless

camera support

Voice Message

Pocket PC Voice Recording System Ideal for Diverse Data Collection with various

groups of people using the unitSave time Accurate and Detailed Database

TrimPix technology support

Support for digital image transfer using wireless LANUsing built-in wireless LAN or

wireless LAN CF cardReceive high resolution digital

images from selected Nikon digital cameras

The easy way to integrate digital images into your GIS

Photographs are rich in detail Photographs can be used

as evidence

Hence : No cost in describing the site Add minimal extra cost but add

more details to GIS datau Free to download from

www.trimble.com/trimpix

Adding Photo to your GIS data

Need to know...

How many people... Where they are … What are the people

nationality in the area... What condition they are… Who are they ? Why?

Answers Tools for better Decision Making

3. GPS Data Maintenance

Building a GIS database is a bit like building a bridge...

It has a design and construction stage…

Data Maintenance

But if its not maintained, it becomes useless and can create problems.

Data Maintenance

Maintenance for a GIS means keeping its data up-to-date, accurate, and reliable.

Features may need to be: added modified deleted restructured

Data Maintenance

Data becomes out-of-date for many reasons, such as:

new infrastructure storm damage changing user

requirements New analysis criteria

Data Maintenance

The Data Collection/Maintenance Cycle

1. GIS to Field

2. Field Update

3. Field to GIS

The way we are heading…

Data UseData Maintenance

Where we have been

Where we are headed

Data Collection

The Future

Further Improvements on GPSCheaper price with more capabilitiesMore accessible to all usersMore Flexible applicationMore Accurate CoordinatesBetter Data Communication

Better GIS data

SummaryGPS is a reliable source of GIS dataTrimble continues to provide the most reliable

GPS ReceiversMore functionalities are added into GPS

ReceiversWhen the Data Collection is done, Data

Maintenance must already been planed and committed

Better Decision Making & Analysis

Thank You.