How to OCAD map onto phone/tablet and use GPS

[Paul Frost]

I know this is possible but have failed to manage it.
I read the Ocad blog post how to do it, but whatever I try I get "Map not referenced". That method uses Avenza PDF maps on an iPad.

What I want is to to be able to view a map produced in Ocad on my mobile screen with a little dot showing my actual position on the map, just like looking at a Google map. I don't want to be able to draw on it or do updates.
I have Ocad and the original map files, so I can export whatever file type is needed. I have an Android phone (Sony Z3 compact), and an iPad (running latest IOS) and it would be good to have it on both.

[Angry Haggis]

OpenOrienteering Mapper, which can read OCAD map files (v6-11) and save them as OCAD v8, has an Android client:

http://www.openorienteering.org/mapper- ... d-app.html

"GPS position display toggle

This will show a dot at your current position. In addition, in case an accuracy estimate is available, this shows a circle around the dot which indicates the positioning accuracy. The chance of your real position being in the circle is approximately 70%."

Download at http://www.openorienteering.org/apps/mapper/

[Jagge]

You can also do it quite easily with ad-hoc RouteGadget. It does just that and plenty of other things. It should work just fine on latest IOS and Android. And no need to install anything, you can use it directly from RG's web site. All you need is map image (jpg/png/gif) and a web site to host your image file, like dropbox.

I suggest studying what it can do if you haven't tried it yet.

[Paul Frost]

Jagge, How do you drag a file into the box when using it on a phone?

[Jagge]

you paste image URL to the text field in that box and press enter. Example, copy paste this URL there and see what happens.

Alternatively you can make direct link and share it. So all those who open the link with their browser can locate them themselves on your map. example

[Paul Frost]

I had tried using a dropbox link but that didn't work, so I uploaded it to a normal server and that worked.
It looks like it's all working OK in Chrome on my Android phone, but in Safari on my iPad the map image doesn't resize when you zoom in and out and then ends up in the wrong place.

[Jagge]

I have seen that happening with older ipad. Worked fine with the more recent iphone (iphone 6), at least last time I tried it.

For dropbox you need to use the direct link, not a share link.

[Paul Frost]

I installed OpenOrienteering mapper on my phone OK and everything seems to be working, except I can't get a location dot on the map.
The manual shows which icon toggles the position display, but it is greyed out and doesn't work. I've checked the permissions for the app and they allow use of GPS. The north alignment seems to be working. Any ideas?

[Paul Frost]

ad-hoc RouteGadget worked whilst I was near home (I don't have a 3G connection locally). So the map image and tiles that were loaded from my WiFi meant that I could click on the pin and my position was updated. But when I got further away and needed to move the map to show my position I got a timeout message and it didn't work, so I'm guessing that it needs a constant internet connection to work. So not ideal for when you are in the middle of nowhere (at least as far as 3G is concerned).

[Jagge]

That must have been gps/location service timeout not network timeout. Maybe you had some kind of network positioning on instead of plain GPS and without wifi it could not locate you any longer. That might also explain why OOMapper behaved like that, maybe it expects GPS positioning being on? That page works just fine with network off after map image getting loaded. But true, not optimal solution for remote areas, if you close your browser by accident or your browser crash you may not be able to open it again.

The objective with this is having easy way to provide service like this to novices or anyone who like to get outdoors and do O with GPS as an additional support. All you need is set link like that up and make it available.

[Simon E]

I installed OpenOrienteering mapper on my phone OK and everything seems to be working, except I can't get a location dot on the map.

I'm assuming you are importing to OOM from OCAD. This seems to lose the georeferencing information every time I do it, and you end up with no GPS as you found. The solution:

1) Import OCAD to OOM.

2) Click on "Map..Georeferencing.."

3) Set "Coordinate reference system" in the dropdown to "Custom Proj.4"

4) Paste your Proj.4 string in the new text box. If you are using British National Grid then you need:

+proj=tmerc +lat_0=49 +lon_0=-2 +k=0.9996012717 +x_0=400000 +y_0=-100000 +ellps=airy +datum=OSGB36 +units=m +no_defs

5) Save as OOM and things should now work.

[Paul Frost]

Thanks Simon, that's working now. That dot is very small though.
Perhaps I'm just not smart enough, but this seems very complicated for what seemed like a fairly simple task.
So where would I have found that string if you hadn't told me?
Is there an explanation of how you are supposed to arrive at that specific answer?
Why Custom.Proj.4 ?

When I open a map that I'm told has just been adjusted to the latest magnetic north by the mapper and it says the Declination is -1.50 degrees, but if I click the Lookup button it tells me the corrected Declination is -2.97 degrees. Which is most likely to be correct?

[Paul Frost]

Jagge, my phone has a setting of "High Accuracy", which uses GPS, WiFi and network to determine location. It does also have GPS only, I'll try that next time to see if that makes a difference. But it was working fine until I moved the map.

[Nimby]

I read the Ocad blog post how to do it, but whatever I try I get "Map not referenced".

FWIW I get the same error with our georeferenced maps. Maybe it doesn't understand British / OS grid? (Or is georeferencing converted internally to a single standard?)

[Jagge]

Jagge, my phone has a setting of "High Accuracy"

That explains it. After exiting wifi range it had to turn gps on and it did not get fix in time resulting as a timeout message. Nothing to do with map panning you would have got that without any panning.

After plenty of experimets I have ended up using gps only for live tracking and all other outdoor sports use. It is far more reliable and accurate for outdoor use than google's that "high" accuracy.