High Sierra Topix

I’ve read conflicting information regarding Globalstar satellite phone coverage in the Sierra. There’s a plan available where you get the phone for $250 and unlimited usage for $9.95 a month, but they don’t guarantee coverage and say I should ask people who've used one in the area. Since the SPOT messenger is also Globalstar, I’m assuming the coverage for the SPOT would be the same as for a Globalstar phone. Anyone have any information/experience on this?

Second hand: A friend had one, and wasn't happy. If the phone loses line of sight with the constellation (which is very common through the hills and valleys of the Sierra), you don't have signal. Quite often you're forced to climb up a south facing slope and find a clear southern viewshed to make a call.

SPOT uses the L-band for communication. Most of the problems associated with globalstar phones are due to the manner in which the sats communicate with gateway stations (see below as taken from wikipedia).

SPOT does not share this problem because it continues to send it's beacon until any sat is within view.

HTH

Globalstar satellites are simple "bent pipe" repeaters. A network of ground gateway stations provides connectivity from the 40 satellites to the public switched telephone network; users are assigned telephone numbers on the North American Numbering Plan in North America or the appropriate telephone numbering plan for the country that the overseas gateway is located in, except for Brazil, where the official Globalstar country code (+8818) is used. Because there is no inter-satellite linking, a satellite must have a gateway station in view to provide service to any users it may see. Because there are no gateway stations to cover certain remote areas (such as oceans areas far from land), no service can be provided in those areas even though the satellites fly over them.

Thanks for the info Eric and Shawn. I now understand that with a “bent pipe” receiver system the satellite will need a ground system to bounce to and from. I don’t think that should be too serious a problem in the Sierra with Bishop, Mammoth, etc., as the ground gateway. But what I’ve found in my research is that as the satellites move, the reception goes in and out so you may only have a minute or so of connect time. That’s not a problem for me since I just want to be able to tell my wife “I’m fine” or (worst case) reach 911. What I’m wondering is how long a lapse there may be between connect times. Is it 10-20 minutes or an hour or more?

Have a look at this thread in TT:

http://www.telemarktalk.com/phpBB/viewt ... globalstar

Thanks Shawn. That answers my question. I guess my wife will have to settle for a SPOT, win the lottery to afford an iridium, or settle for the cell phone like she has for the last 10 years.

I used both the Iridium and Globalstar Sat phones this summer. Iridium seemed to be better, though still pretty frustrating if you expect to have an actual conversation. I was rarely able to get a signal with Gloabalstar from a point without a full horizon. With Iridium, I was able to do so from the same location, but rarely for more than about 3 minutes. Still, in an emergency, that's enough. Ideally, that's all you're carrying the gizmo for in the first place. Obviously, the better your full horizon, the better your chances of a connection.

g.

PS:

They don't seem to work at all through a cloud cover either.

g.

I second gdurkee! I too used both sat phones this summer (the Iridium and Globalstar). I used the Iridium in the NWT - Canadian bush and I was able to have great conversations most of the time, at all hours, locations, and conditions. I used the Globalstar in Nunavut - Canadian Arctic and had to reserve communication for email - very frustrating. No doubt my wife preferred the Iridium. I have also used the SPOT on many occasions to check in. It does work all over the world. We have to take them out with us when we travel and work in remote locations. The SPOT check subscription also includes an insurance policy option I think where the sat phones do not. I think you can subscribe for up to a 100K dollar policy which may come in handy god forbid. Although, we did tested the accuracy of the coordinates the SPOT provides this summer and it did not give me much confidence if I was disabled or injured such that I could not travel. My brother-in-law and wife flew over my location in a Cesena and were way off from where I was. I saw them fly over but like a click or two NNE of my location. If I was in an emergency situation and needed to be located via SPOT coordinates I wouldn't be at ease, but SPOT does work well for checking in!! I think I would rather rely on smoke signals in some instances.

Bad Man From Bodie wrote: Although, we did tested the accuracy of the coordinates the SPOT provides this summer and it did not give me much confidence if I was disabled or injured such that I could not travel. My brother-in-law and wife flew over my location in a Cesena and were way off from where I was. I saw them fly over but like a click or two NNE of my location. If I was in an emergency situation and needed to be located via SPOT coordinates I wouldn't be at ease, but SPOT does work well for checking in!! I think I would rather rely on smoke signals in some instances.

Thanks for the info. As for the spot accuracy, I list myself as a contact so I can check the accuracy via google maps when I get back home. It's never been more than 100 meters off. I don't know how this would work if someone else had a GPS and was trying to find me.