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Australia | Tim,
Our support team can handle this for you but here goes anyway.
In order of asking:
1) You want both the whip and GPS antenna as close as possible to the base to reduce RF loss. If you want to go high with the whip or far with the GPS antenna then you will need 'low loss' cable or even a booster. You will need your local two-way radio specialist to help here as he will need to eyeball your situation for a cable recommendation.
2) Maxstream repeaters can be permanently fixed to repeat the correction into a poor coverage area say in a valley or in a wooded area.
3) Go to www.maxstream.net and look at their repeater specs (Xtend NEMA RF Modem). 5 miles should not be a problem.
4) If you wanted two base-stations you would need to set-up each "mini-network" on two separate frequencies so they don't clash. So on the mojoRTK console you would need to change channels when you move to the other area.
5) The repeaters will only work for the base-station they are connected to. You cannot have two base stations sending different correction information on the same channel so its not practical anyway. DOT networks have this capability because they spend millions on products like Leica Spidernet and Trimble VRS.
6) We estimate that it is not wise to 'repeat' the signal more than two hops. You start geting 'lag' in the corrections which reduces reliability and accuracy. You can repeat in opposite directions (use directinal antennas) where the repeaters cannot hear each other though. The GPS 'baseline range' of the mojoRTK is 16 miles radius so hopping beyond 16 miles is pointless as you will begin to lose accuracy. On a 'good constellation' day you can get up to 24 miles with Leica RTK but this will not be consistent. It is important to understand that 'radio range' and 'GPS baseline range' are different concepts. There are two papers on this on our website.
7) Someone in the middle would need to select the right channel on the mojoRTK console to use the right base.
8) It doesn't matter which base a user chooses as long as they have good signal strength and they are within 16 miles of that base. As said above they can be further than 16 miles but we don't guarantee the performance.
9) The mojoRTK correction data is encrypted to stop anyone using it who doesn't own the station. If you buy a CMR or RTCM upgrade for the base then receivers that can accept these correction standards can use the base stations but it will be open for all to use... which you may not have a problem with.
10) The standard baseline that comes with the mojoRTK console is 4 miles. The accuracy begins to gracefully degrade after this. The next step is 8 miles which costs $1290 one off; and the last step is 16+ miles which is $2490. We use Virtual Wrench for the upgrading. Most people who use the base as a portable unit will never need more than 4 miles. Note the base station does not need to be upgraded, just the console. The base will transmit the corrections as far as physically possible.
11) The baseline upgrades do not care whether a repeater is there or not. The range is calculated from the base station GPS antenna position.
You can see this is complicated and we do recommend you use the RF skills of your local radio specialist. This stuff is bread and butter for them.
Cheers
John | |
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Thank you guys
