Christopher R. Bennett EASTR GIS Data Collection Christopher R. Bennett EASTR

Overview of Presentation Introduction Spatial Data Options for Collecting GPS Data Examples of Output 2

Introduction

Background to Project Sponsored by EAP Innovation Fund $30k to investigate spatial tools for project preparation and supervision Project looked at Opportunities for spatial data on projects Data collection techniques Ways of managing data 4

Findings Project completed January 2006 Recommended EAP commit to using spatial data on projects Proposed: Using GPS Enabled Camera to collect data Google Earth to manage data 5

Spatial Data

Spatial Referencing Any location can be expressed as the latitude and longitude A unique and permanent way of identifying location 7

Types of Data Vector Raster Points, lines (two or more points) and polygons (multiple lines) Each point is represented by (x,y) co-ordinates corresponding to latitude and longitude Raster Usually images 8

Ways of Collecting Data GPS Surveys Data collected using Global Positioning System (GPS) GPS uses satellites and triangulation to get the location Digitizing Existing maps are converted to digital Aerial Photos and Satellites 9

Principles of GPS Measurement Run by US Department of Defense 24 satellites at 20,200 km altitude Normally 5 satellites can be viewed anywhere in the earth Satellite sends a radio timing signal Time measurements used to establish distance from satellite 10

GPS Locations By observing a minimum of 4 satellites (3 position; 1 for time) location can be established More satellites in view gives better accuracy 11

GPS Accuracy Depends on The number of satellites in view The equipment Typical consumer equipment +/- 8 – 10m with 95% confidence Survey grade instruments +/- 2 m or better Accuracy improved by: Differential correction Signal from GPS base station or similar 12

Example of GPS Accuracy Uncorrected: +/- 1.2 – 6.3 m; Corrected: +/- 1.1 – 1.6 m 13

Example of GPS Accuracy - Apia 14

Options for Collecting GPS Data

Overview Project field tested different equipment Handheld GPS receiver Personal digital assistant GPS enabled camera All were found to be suitable for us 16

Data Needs GPS data Point data: data at a single location (x,y) Continuous data: set of (x,y) data representing a line (eg road) Most preparation and supervision projects need point data Spatially referenced digital photographs valuable 17

Data Definitions Area Issue Safeguards – Environment (SE) Air Pollution Dust Pollution Noise Pollution Property/Land Damage Water Pollution Other Safeguards – Resettlement (SR) Compensation Level Completion of House Demolition Completion of Land Acquisition Property Replacement Engineering (E) Construction Quality Design Issue Safety Issue Inventory (I) Clinic/Hospital Casting Yard Construction Camp Materials Storage School Important to ensure consistency when defining what data collected Identified simple codes for range of issues 18

Handheld GPS Receivers Many different types available Consumer models cost < $200 Project use Garmin e-Trex Garmin most widely supported by 3rd party software Can store about 10,000 points 12 channels so should give good accuracy 19

Garmin Findings Robust unit with good battery life (17 h for 2 x AA batteries) Very simple to use in the field For continuous data travel to site and turn on Useful to have windscreen mount for unit Not easy to enter point data description 20

Personal Digital Assistants (PDAs) Tested Windows based PDA with CF-Card GPS Data Collected with: Custom software Data Logging GPS2Googe Earth 21

PDA - Pocket PC Creations Software designed for rapid development Data ported to access Good for proof-of-concept Several problems: Was not able to collect continuous data Difficult to install Expensive to deploy 22

PDA - GPS Data Logging Many applications store GPS data Simple to use: Turn on GPS Software logs data Only disadvantage was inability to store point data 23

PDA - GPS2Google Earth Low cost (<$20) Simple application to record point and continuous data and export GE files Simple to use and with some refinements ideal for Bank data collection 24

Digital Photographs and GPS Digital photos (.JPG files) can have spatial co-ordinates added to header When read into GIS/GE image correctly postioned. Two options Link digital photos to GPS log data GPS enabled camera 25

Digital Photos – Linking To GPS Time of photo matched to GPS log data Used Robogeo (v 3) ($50) software After GPS data matched created GE file 26

Robogeo Matching 27

Digital Photos – GPS Camera Camera with embedded GPS records spatial data along with photo Very easy to use Project tested Ricoh Pro-G3 More details in next presentation 28

Examples of Outputs

Comparison of 3 Devices Recorded data in same location with Handheld GPS, PDA and GPS Camera Excellent agreement 30

Shiman Highway Project – 1 31

Shiman Highway Project - 2 32

Shiman Highway Project - 3 33

Cambodia GIS Import 34

Thailand GPS Image 35

Satellite Image 36

For More Details Download the report ‘Using Google Earth on World Bank Projects’ from www.lpcb.org 37

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