gps antennas

i need to fix wireless antennas in two points, i have gps co ordinates on both sides , how to calculate the exact height on both ends to fix that antennas

http://www.google.co.uk/search?sourceid= navclient&ie=UTF-8&rlz=1T4ADBR_e nGB297GB297&q=wireless+antennas+usin g+gps%3f

2009-06-19 12:31:13 by jsaran77

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I have a garmin etrex legend and i want to take some measurements by driving my car. But the gps looses the signal inside the car. So I was wondering.. Is garmin etrex legend compatible with external antennas? If so could you suggest some models compatible?

I am assuming that you have an earlier one with the gray scale screen and a serial port interface. The new ones receive signals much better.

The basic answer is no. There is no official way to attach an external antenna.

Some people have created "reradiating" antennas for them. It is an external antenna that is attached to a transmitter with an antenna that you set next to your GPS.
This link will give you a search on some of them - http://www.google.com/search?hl=en&r ls=org.mozilla%3Aen-US%3Aofficial&hs =G5Q&q=etrex+reradiating+antenna& ;btnG=Search&aq=f&oq=&aqi=
For creating tracks, visibility of the GPS is not as important.
Make sure that you have the GPS in position where there is no metal or parts of your body between it and the sky, like as far forward possible on the dash or taped to the windshield. Metal and moisture block the signal.

The big buck option is to buy an etrex with H after it. That indicates the high sensitivity receiver. I rarely get drop outs with my Vista HCx. It will even record tracks inside my house or if I sit on it in my car.

The x versions use MicroSD cards for effectively unlimited storage of tracks. It will record as many points as you can (up to a point a second) as long as the GPS is turned on. It breaks the files every 24 hours of recording.