[Qgis-user] New starter on QGIS & I need help!!!!!

[DB]

On 05/16/2011 06:01 PM, pcreso at pcreso.com wrote:
> Click plugins, manage plugins then locate and enable Georeferencer
> (you may need to download Python plugins first)
>
> Use this tool to click on points on the map, & specify/enter the UTM
>  coordinates for these points.
>
> Do this for several points scattered throughout the image. Once done
>  (accurately!) QGIS will correctly locate the image on the map, and
> therefore properly place any points or lines overlaid on it.
>
> This is not the only way, but is perhaps the simplest.
>
>
> HTH,
>
> Brent Wood

>> Hello Dave,
>
> I believe that QGIS is in fact the right tool for you to use.
>
> In a normal case you would need to load both .map file in QGIS. Then
> using the georeferencer plugin, load the JPG and start giving known
> coordinates (the ozi file points, using the "From map canvas tool")
> to places on your image. After at you will be able to georeference
> the imagem and load it in QGIS.
>
> With a bit of luck, all the points in your ozi file are in the same
> coordinate system (It would be very strange if it didn't...),
> probably WGS84 geographic coordinates and you don't need to worry at
> all.
> Hope I have helped.
>
> Alexandre Neto


> --- On *Tue, 5/17/11, DB /<Freddog_de at yahoo.co.uk>/* wrote:
>
>
> From: DB <Freddog_de at yahoo.co.uk> Subject: [Qgis-user] New starter on
> QGIS & I need help!!!!! To: qgis-user at lists.osgeo.org Date: Tuesday,
> May 17, 2011, 2:12 AM
>
> Hi all,
>
> I've just loaded Qgis under Fedora 14 to try and do some of the
> things that happen in Oziexplorer. (I'm an official at a number of
> Hot Air Balloon competitions where Ozi is currently used for
> evaluating GPS tracks)
>
> I've managed to get our (next)competition map loaded into qgis, but
> haven't yet found a way to fix the scale of the map. It is a 50000
> map which has been scanned to jpeg. We also have an ozi .map file
> which would appear to my pretty much untrained eye to be the info
> which identifies the UTM coordinate system in use on the map.
>
> My first question to you guys is... how do I tell qgis to convert the
> pixel(?) counts to UTM grid?
>

Hi Brent & Alexandre,

Thanks for your help....  B u t.. after a lot of playing with qgis &
Georeferencer, I'm still stuck!

I guess there must be a clarification hidden in a document "Somewhere
over the rainbow", but I have to confess, I can't find it - usual
problem of an otsider coming in & expecting everything to work
automatically, RTFM only to be done as a last step!

OK... so I started Georef, saw how the information got put out & made a
file containing the 9 UTM cross points as given in Ozi's .map file.
Restarted, danced 3 times round the maypole & eventually got my 9 points
to plot on the Georef mini-map & the QGIS big map - yippee!  and in the 
right places!!  BUT I don't
seem to be able to tell anything what these 9 points represent.

In Ozi .map, I have

point01,xy,2412, 2380,in,deg, , ,N, , , W,grid,31,704000,5552000,N
point02..... etc.  In Georef all I appear to be able to input is
2411.496,-2379.907 under SrcX & Y, which turns into

mapX,mapY,pixelX,pixelY,enable
2412.000000000000000,-2380.000000000000000,2412.909978693178800,-2382.054865056816197,1
in the GCP "points" file
  Nowhere for the UTM 31 N 704000 5552000.

If I double click on any of the boxes in the table, I get sent of to a
transformation panel which might as well be written in hieroglyphs for
all I understand of it!

I selected
Transformation Type: Linear
Resampling method: Linear
Output raster: /home/Dave/Desktop/Luxgsm/map/trial_01
Target SRS: EPSG:32631
Set Target Resolution: on
Horizontal: 1.00000
Vertical: -1.00000
Load in QGIS when done: on

With this I get on the Georef window bottom panel:
Transform: Linear Translation (-0.326581, 0.800639) Scale (1.00004,
1.00008) Rotation: 0 Mean error 0.717116, followed by the current mouse
coordinates.

I guess (!) I'm quite a long way into my trial, but, like Hansel &
Gretel, I can't see wood for trees!!!  I've tried the qgis "easy
guide", but it doesn't appear to go where I want;  I tried the Georef
help....  At least I now know that a GCP is a Ground Control Point!

So, my plaintive voice in the wilderness(!!), can someone either give me
a cook-book sequence of How-tos to make Qgis recognise my UTM grid(s) or
point me to a Beginners Guide somewhere in I'net space????

BTW, I have to deal with 2 UTM bands 31N & 32N.

Many, many thanks for any help

Dave