[OSM-newbies] Wiki documentation on GPS devices - please help answer some questions

[Dudley Ibbett]

Hi

Battery life and replaceable batteries are likely to be a debate for anyone purchasing a dedicate handheld gps, phone, tablet or logger.  If you need a device that lasts for the longest time possible in the field then having the capacity to replace the batteries is probably going to be the most important consideration.  I don't think this is an option for a tablet but it will be for all the other devices.  There's nothing more annoying that having a device die on you half way through a mapping survey.  If you have the money then a backup logger is a good idea and will enable you to compare gps signals and asses where reception/accuracy might be poor.

Other issue when choosing a device will be whether it is waterproof/showerproof.  Loggers tend not to be but you can just put them in a plastic bag.  I believe you can get waterproof/showerproof phones but if there anything like cameras, in this respect, you will pay a premium.  Waterproof bags are also available for phones.  Dedicated gps navigation devices (i.e. that support navigation and possibly maps) will generally be waterproof and more robust should you drop them as they intended to be used in all types of weather.    

Software compatibility with your operating system can be problematic.  Older devices may not work on the latest version of MS windows and support for Linux and iOS is likely to be more limited.  Third party software such as BT747 may work but I'd always take at a look at the reviews to see if there is useful information on this.

If you want to use your gps to record information against a waypoint then a gps logger should be avoided as they wont do this. They will however record a waypoint and using a cheap digital camera and photomapping is a very easy and much quicker alternative.

The lightest and smallest devices are likely to be gps loggers.  People attach them to the tops of cycle helmets and put them under caps to get good reception.  The size and weight of other types of devices will vary but they are all designed to be held for extended periods.

I think that determining how accurate a device is in terms of its suitability for mapping is quite difficult.  They're all designed to provide an accurate position and I suspect they will provided this if an adequate number of satellites is in view and the satellites are in a broad geometry.   My original Garmin etrex use to loose the gps signal under trees and in narrow valleys.  My Garmin 62s doesn't do this (it has an external aerial) but I'm not entirely convinced that the recorded position is very accurate in these circumstances when it comes to mapping.  

GPS loggers will the cheapest device to purchase.   When you add 
in priority maps the cost of the other devices can start to really stack
 up by comparison.  Which brings me to the last point which must be that
 if your going to have a gps with a screen that supports maps it must surely support OSM maps!!!

Kind Regards

Dudley
 

 

> Date: Sat, 26 Jan 2013 11:08:30 +0000
> From: lists at mail.atownsend.org.uk
> To: newbies at openstreetmap.org
> Subject: Re: [OSM-newbies] Wiki documentation on GPS devices - please help answer some questions
> 
> Neil Taylor wrote:
> > To pick up on Andrew's point. The battery life we have seen on lower end smartphones (Samsung Galaxy Pocket) deployed in the field (in Cebu in the Philippines) when using GPS to send regular location traces to a server (not OSM, but would be indicative of battery life of doing this) is 3-4 hrs depending on conditions and intensity of use.
> 3-4 hours does seem a tad low - In my experience (Blackberry 9700) 
> continual GPS tracking would reduce the battery life (perhaps from 24 
> hours to 12), but not be anything like to that extent, and not anything 
> like as much as if I was keeping an eye on the football or cricket 
> scores.  Maybe it's the "server access" part that brought life down to 
> 3-4 hours?
> 
> How often the software's accessing the GPS (in OSM applications it's 
> going to be "hot" the whole time, in others perhaps not) and other 
> servers is going to be key - and obviously phones vary in terms of 
> battery life anyway - bigger/smaller screens, bigger/smaller batteries, 
> different OSes etc.
> 
> Cheers,
> Andy
> 
> 
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