http://www.crg.ulaval.ca/

GPS TELESCOPIC MAST
Canadian Patent Number 2 097 774

USE OF A GPS TELESCOPIC MAST
A telescopic mast is used to raise the antenna of a GPS receiver above the obstructions (trees, buildings,...) present around the observing site. The goal is to improve the reception of the satellite signals which enhances the quality of the positioning results and increases the productivity of GPS surveys, keeping in  mind the protection of the environment. A telescopic mast yields surveys with a precision at the centimeter level in places where it would otherwise be impossible or unproductive to use GPS.

TECHNICAL DESCRIPTION

Material:
Weight:
Lenght:

Set up:

Height measurement:
Verticality:

Transportation:
aluminum
30 kg
4 meters (undeployed)
10 meters (deployed)
10 minutes (with 2 persons), at about 1 cm of precision
measuring tape
spherical level and
inversed tribach
on a car roof or in a transportation bag with shoulder straps

SET UP VERIFICATION
Comparison on a 500 meters baseline (open field)
Difference between tripod and mast solutions:
                    DN = 1.2 cm    DE = -0.6 cm    Dh = 1.3 cm

RESULTS IN WOODED AND URBAN AREAS
Comparison on baselines of about 1 km established by conventional methods.
The GPS sessions last 30 minutes.

Tripod (rms):

DN = ±13 cm

DE = ±11 cm

Dh = ±39 cm

Mast (rms):

DN = ±2 cm

DE = ±2 cm

Dh = ±2 cm

REFERENCE
Santerre, R. et Roy, Y. 1993, Optimisation de l’utilisation du système GPS en milieu boisé, Geomatica, Vol. 47, No. 1, pp. 39 à 46

     Mât télescopique
MatGPS1de3mStmini.JPG (24779 octets) MatGPS2de3mStmini.JPG (18544 octets) MatGPS3de3mStmini.JPG (12473 octets)

http://Patents1.ic.gc.ca/intro-e.html