200 likes | 229 Views
AUSLIG Online GPS Processing Service (AUSPOS) John Dawson, Ramesh Govind, John Manning Concepts AUSPOS Background How it works. STEP 1. Local Survey Mark. Geodetic Survey Mark. STEP 2. New Survey Marks. Local Survey Mark. STEP 1. www.auslig.gov.au. GPS data via Internet.
E N D
AUSLIG Online GPS Processing Service (AUSPOS) John Dawson, Ramesh Govind, John Manning Concepts AUSPOS Background How it works
STEP 1 Local Survey Mark Geodetic Survey Mark STEP 2 New Survey Marks Local Survey Mark
STEP 1 www.auslig.gov.au GPS data via Internet New Survey Marks Local Survey Mark
What is AUSPOS? • Internet web application • users submit geodetic quality GPS via web-browser • rapid turn-around precise positions via email • cm level coordinates anywhere in the World! • including Antarctica • position quality depends on data quantity/quality • local datum within Australia (GDA94) • ITRF coordinates outside of Australia • FREE service
What do you Need? • GPS data • dual frequency data • > 6 hrs of continuous • Internet web browser • i.e. netscape, Internet Explorer • Email address
User GPS Data Processing Results Coordinates (email)
What do you Submit? • GPS data (RINEX) • Your email address • the height of your GPS antenna • the type of your GPS antenna } height
Speed and accuracy • 6 hour data file • results delivered in ~ 3 minutes • 20 mm horizontal, 50 mm vertical • 24 hour data file • results delivered in ~15 minutes • <10 mm horizontal and 10-20 mm vertical
How it works • International GPS Service (IGS) • worldwide network of permanent GPS receivers • ‘baseline’ from three closest GPS • station to station distances • Antarctica -- typically 1000 km to 3500 km IGS IGS User GPS IGS
AUSPOS, GPS Errors and Models • state-of-the-art processing system (MicroCosm) • IERS96 conventions • orbit error • uses IGS precise orbits • receiver and satellite clock error • eliminated by double difference • troposphere refraction • scale factor estimated • ionospheric refraction • dual frequency observations • antenna phase centre variations • uses IGS phase centre models
AUSPOS Applications • DGPS reference station positioning • Remote GPS station positioning • Ultra-long GPS baseline positioning • GPS connections to IGS and ARGN stations • High accuracy vertical GPS positioning • In the field high-accuracy processing • GPS network quality control
AUSPOS Applications in the Antarctic • provides access to high-accuracy GPS processing • free and easy to use • high level ITRF geodetic control • remote Antarctic locations • single GPS receiver
Useful Internet GPS Resources AUSLIG home page www.auslig.gov.au AUSLIG Geodesy home page www.auslig.gov.au/geodesy/newhome.htm AUSPOS home page www.auslig.gov.au/geodesy/sgc/wwwgps/wwwgps.htm IGS home page igscb.jpl.nasa.gov