Importing UK maps into OziExplorer

Hi John

As you appear to have established you just use the DRG import option.

Just wondering what Zone you selected during the import process of the calibration data from the TFW files. Most of Great Britain appears to be zone 30 but Im not sure that applies to all the 250K maps? Did you use Zone 30 for all of then? I dont have time at moment to check UTM zones for the area. If there are several UTM zones across Great Brittain you will need to import the calibration data from the TFW files in subsets of maps that are in the same zone. Importing the data all at once using one zone setting will results in errors (if a map falls into another zone).

Cheers
Greg

Hi
Just looked at Google Earth and Great Britain covers three UTM Zones, 29, 30 and 31...so if the calibration data you are importing is in UTM (the copy I have is) you will need to figure out which maps fall into each zone before importing as OziExplorer asks for the Zone during the import process. This maybe easy if you can figure out what the map names mean..there must be a system.

I have assumed also that the datum is WGS84 - though cant see this confirmed anywhere.

Someone has surely done this before...maybe a set of calibration files out there already?

Cheers
Greg

Hi

Thank you for your thoughts. Zones??? Ozi didn't ask about that. There is a box to tick "Use Geotiff if available" which I ticked - not sure what that means, but I trust Ozi to do the best it can with available resources. "If available" is a nice touch too which shows that Ozi is very much on the ball!

I've now got 40 or more (?) map images and .map files each covering a 100 km square area, and Ozi seems able to select the one to the N, E,S etc reliably and move between them, so I'm assuming that any zone considerations have been dealt with. (Obviously since I'm currently in Australia I don't know how moving map will work on the ground!)

The only big thing I'm missing that we expect in our Australian Natmap 250k set is the "map view" image of the whole country. That would be really useful so one could select the area of interest. At present each of the 100 km square tiles provides its own "map view" which isn't very helpful when one is stumbling around. Bit like trying to follow the CSR without knowing that you are looking at Victoria! Is there a simple way of creating a single file from those calibrated tiles to create something similar to the Aus arrangement?

Another minor irk is the very comprehensive "place names" list which appears to reference something other than lat/long. Since it's required to be in db4 format that's no problem, provided I can first find out what it is referring to. (eg "Abbey Dore*COUNTY OF HEREFORDSHIRE*338460*230630" just doesn't have an obvious relationship with lat and long!)

Why the interest in UK when we normally aim to travel in Australia? One of our sons is over there for a year or so, and we'd like to see what's holding him there! With a base there and the A$ encouraging overseas expenditure there'll never be a better time to see why everyone wants to come here!

Why Ozi in the UK? We want to explore with the help of a familiar friend. The savings in car hire alone will easily buy an android tablet to run Ozi.

Again, thank you for your input Greg.

Cheers

John

Hi John

I may be barking up the wrong tree ..not sure. You got me interested so I downloaded what I assume to be the same maps you have (250K maps called HP.tiff, HT.tiff etc etc from the ordinance website).

The ones I have cant be imported using the geotiff function as they are not geotiffs. The world files are however included (*.TFW) so these can be used to import the calibration data ...but they appear to be in UTM format. Hence my previous comments...

GB covers three UTM zones so you just cant import all the data at once as Ozi needs to be told what zone each map is in - this information is not included in the TFW file...anyway to cut along story short this is what I discovered with the maps I have...if your maps are geotiff thats fine - as full info should be included...though I would be interested to know where you aquired them from.

I would however double check them all by cross referencing locations in Google Earth or similar just to be on the safe side. Just because ozi can move around Ok doesnt confirm correct calibration.

RE: Place Names - they, like the TFW files appear to be in UTM. e.g. 338460*230630 - one is the easting and one is the northing in metres. This is no problem unless different locations are in different zones as Ozi needs to know the zone before it can use the coords as, for example 338460*230630 could refer to a location in a number of different zones. Look up UTM zones via google to get an idea of what I'm talking about.

Cheers
Greg

John

Figured it out. The images are not Geotiff..but I'll have a guess and say you also had the supplied *.tab files in the same folder as the map images when you did the import in OziExplorer?

The tab files are used by Ozi to get the full calibration information - hence your successful import (p.s. you dont need to have the geotiff option ticked for this to work by the way). I tried using the TFW files - these didnt work without adding addition info manually.

I didnt know *.tab files could be used so learnt something new.

Also the coords in the place name file you have are not UTM as I suspected but Tranverse Mercator ...using "Ord Srvy Grt Brtn" datum. Using this information you could make a waypoint file from the data (create and save a csv file in excel) and then convert this to a Name search file using Name Search Creator available on the Ozi web page.

Happy travels

Sorry for talking to myself for most of the way through this :)

Cheers
Greg