GPS - entry by OS grid ref

[RogerL]

I'm finally going to take my head out of the sand on sat-nav.

I need one for driving and walking - I want to be able to define the route, myself, by OS grid ref waypoints (rather than letting the system select the route).

I haven't even found a website or product test that compares features like this.

Any suggestions?

 

[rob_jax]

Hi Roger,

You may need to buy two devices, one for walking and one for the car.

The dedicated car systems, like the TomTom One or Garmin i3, all the way up to the TomTom GO 700 or similar that map all of Europe, are designed to follow roads. You can see the lat. and long., and on the TomTom you can plan the route with multiple "go via"

Some of these have internal batteries so they can be used away from the car for between 1 and 4 hours, but if you are serious about walking, rambling, or orienteering then you would be better served with a Garmin eTrex - they have very long life and allow you to have total control over the way points.

I use one of the eTrex models in my Libelle 301b glider - it allows you to set way points and doesn't expect you to follow the roads.

Robert

 

[rob_jax]

Roger,

Sory I didn't answer your question about the website - take a look at www.expansys.co.uk

Robert

 

[ProfJohnL]

Hello RogerL

Just to reemphasise Rob-jax point about car GPS systems, In my area there has been a lot of new road building, which has not yet been include on the common mapping platforms (i.e. Tom Tom, Medion etc).

When travelling on some of these unmapped roads the car Satnav seems to read my position, then tries to display me on a road that runs close by. I have tried to establish how far this 'snapping' effect tries to correct for positioning errors, and so far its typically 30meters but at worst its nearly 300 meters! then it gives up and shows me moving over virgin space. For that reason alone they are not suitable for hiking.

It's worth adding that when you are on a mapped road the positional accuracy can be much better - given enough satellites to lock onto it will be at best 3 meters but more typically 10 to 20 meters

I don't know of any dedicated car Satnav that allows you to enter OS grid references, But as Rob says the Garmin Etrex range certainly will, but they wont do the same job as a car Satnav and give you turn by turn directions.

Microsoft auto route and some of the other PC based systems will allow OS grids and Lat & Long entries, but, you have to know which meridian reference scheme the system uses for its data - The UK along with most other nations have their own specific Lat & Long references, and the differences between the schemes are sufficiently large to give some positional differences.

Currently all the Satnav systems use the American GPS satellites, which give data based on the American Grid, The Etrex systems allow you to compensate for these different grids, and it can recalculate for the UK OS coordinates. It also offers several other compensation schemes for other parts of the Globe. The point being, My Medion car GPS can produce Lat & Long reading, but if you trace it onto an OS map, there can be a significant positional error (I tied last year on our canal holiday and it placed me several meters of to the side of the canal!. By comparison, my Etrex compensated for the OS grid references produced results that were very accurate, almost identifying which side of the canal I was on!

I do not know of a consumer Satnav system that performs both Street navigation suitable for cars, and as a trekking/hiking aid. It's horses for courses I'm afraid.

 

[Mark_5040952]

Hi Roger

Have a look at the Garmin Quest.

I have one for use on my motorbike as I can plumb it in to my autocom system so that I can hear it through my helmet, I use it in the car as it comes with all the leads etc and I also stick it in my pocket for walking around towns etc.

The unit is about the same size as a mobile phone, is totally waterproof to a depth of one meter, and has internal batteries so that you can use hand held.

You can also get all the routing software so that you can plot your own waypoints etc. If you are off road ie walking etc then it will chart your path and guide you back if you need it to.

I would really suggest getting a friend to show it to you, or if near Weymouth I will!

The unit can be bought online for about 220 pounds.

Hope this helps,

Mark

 

[Mark_5040952]

Sorry Roger,

Forgot to mention, you can also set it up to accept OS Grid references.

To do this, go into

Settings - Units - Datum - then scroll down to OS Grid UK.

By doing this you'll find Robert's your dad's brother!

Cheers

Mark

 

[Mark_5040952]

Also!

You need to change Location Format to British National Grid,

Settings - Units - Location Format.

Officers and maps eh!!

Toodle Pip

Mark

 

[RogerL]

Thanks, both.

Mark, I need to checkout the Garmin Quest in greater detail.

John L - I specifically want a system that I can choose the route, not rely on the system. I don't need turn-by-turn instructions, just direction and distance to next way point. I think I want GPS but don't need sat-nav but I don't know what's available. It's not rocket science to accurately convert UK OS grid ref to lat/long or vice versa, surely all of these systems can handle that!

 

[Steve L]

I have a Garmin i3. This is able to be hand held and 2 aa ni-cad batteries last approx 6 hours. By coincidence we use the same batteries to power the digital camera sowe have plenty of spares.

It can be set to do uk grid reference, andfor it's size I think it performs well.

Ease of use impressed me, as I'm a new starter to gps like you.

Cost was good too. About

 

[ProfJohnL]

Hello Roger,

I bow to the greater experience of other members. I am not familiar with the Garmin Quest that Mark suggests, It sound like it could be what you are looking for.

The point about conversion from Lat & Long to OS grid references is significant if you intend to try and use a car type Satnav to fix your position on an OS map. The differences in the way the Lat & Long grids are Datumed, will generate false positional information ulsess you have the correction codes. It is imperative as Mark suggest that to use a GPS with and OS maps, you must select the correct Datum, and location formats to British National Grid. It sounds as though the Garmin Quest may do this.

The other diffence between Street mapping and wayfinding, is that with wayfinding, you pre-define the OS grid references you want to visit. The system will point to the next way point as the crow flies. It is not inteligent about obstacles.

The Street Pilots work by routing along mapped roads, but as there are no roads in many of the places you may wish to hike then clearly they can't be relied on.

I have just done some research on the internet about the Garmin Quest, and whilst it seems it will provide some directional information it is primarilaly a street Pilot system. I sugegst you very carfully check out its capabilities against your expectatins before purchase, as i am sure you will

 

[Lord Braykewynde]

The Garmin Quest has an inbuilt battery with a life of approx. 20 hours before it needs recharging. Garmin have brought out the Quest 2 now which is more expensive but allows you to download Points of Interest.

 

[BarryP_5039912]

Hi Rogerl

i use a Garmin vista c for both driving and in hills and it does the job really well.You can programme it to suit road or off road.Good road detail but you need to buy extra software to get upto date changes. I would certainly recommend this unit.

Barry

 

[cris_408518]

Steve in Leo. Can you explain how you can set it to grid ref for the UK as I have all the latest upgrades on mine and can't find how this is possible.

I hvae used the I3 to set my start point so I find my way back if I get lost in the countryside walking the dogs and I'm interested in what you say about grid ref.