Oruxmaps desktop and Spanish datums - technical questions

Started by MapMan, May 29, 2014, 10:09:13 PM

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MapMan

May 29, 2014, 10:09:13 PM Last Edit: January 01, 1970, 01:00:00 AM by Guest
I use OruxMapsDesktop to create offline maps to use on my phone. One of the inputs to this program is a calibration file, which is in OziExplorer .map format. Unfortunately, I don't own a copy of OziExplorer but I am a software developer with a mapping application that I wrote myself (MapMan - you can Google it if you are interested). My application can generate OziExplorer map files, but currently only for maps that use the WGS84 datum.



I want to create an Orux-compatible map for a region of Spain I shall be visiting later this year. I have scanned in a paper map and my application is capable of calibrating it. On my Spanish map is written: "Datum Europeo 1950".



Now as I understand it, the European 1950 datum comes in different variants. There is EURA, which is the mean for Western Europe. There's EURD for Portugal/Spain, EUR7S for Spain excluding the NW and EUR7SNW for NW Spain. Which of these is my "Europeo 1950" map likely to be?



Once I have identified the precise datum, I need to know exactly what OziExplorer would call it. For a WGS84 map, the fourth line of an OziExplorer .map file reads:

     WGS 84,,   0.0000,   0.0000,WGS 84

What character string should I use to replace "WGS 84" for my Spanish map?



Any help with the above would be greatly appreciated. If anyone has a sample OziExplorer .map file for anywhere in Spain, that might be a help too.



Kind Regards

Keith ("MapMan").

orux

#1
June 02, 2014, 06:09:33 PM Last Edit: January 01, 1970, 01:00:00 AM by Guest
Quote from: "MapMan"I use OruxMapsDesktop to create offline maps to use on my phone. One of the inputs to this program is a calibration file, which is in OziExplorer .map format. Unfortunately, I don't own a copy of OziExplorer but I am a software developer with a mapping application that I wrote myself (MapMan - you can Google it if you are interested). My application can generate OziExplorer map files, but currently only for maps that use the WGS84 datum.



I want to create an Orux-compatible map for a region of Spain I shall be visiting later this year. I have scanned in a paper map and my application is capable of calibrating it. On my Spanish map is written: "Datum Europeo 1950".



Now as I understand it, the European 1950 datum comes in different variants. There is EURA, which is the mean for Western Europe. There's EURD for Portugal/Spain, EUR7S for Spain excluding the NW and EUR7SNW for NW Spain. Which of these is my "Europeo 1950" map likely to be?



Once I have identified the precise datum, I need to know exactly what OziExplorer would call it. For a WGS84 map, the fourth line of an OziExplorer .map file reads:

     WGS 84,,   0.0000,   0.0000,WGS 84

What character string should I use to replace "WGS 84" for my Spanish map?



Any help with the above would be greatly appreciated. If anyone has a sample OziExplorer .map file for anywhere in Spain, that might be a help too.



Kind Regards

Keith ("MapMan").


Hi, Keith



The European Datum 1950 is unique. What changes are the parameters of the formulas used to transform coordinates to WGS84 Datum. The error is greater the farther the point for which the parameters were calculated. So you will see many variations of some Datum; one set of parameters for country, more or less, if using Molodensky transformation formulas.



An example of a map of Spain with that Datum.



But if you want, you can use the map with all coordinates in WGS84 Datum.


Code Select

OziExplorer Map Data File Version 2.2
Sierra nevada.jpg
Sierra Nevada.ozf2
1 ,Map Code,
European 1950,WGS 84,   0.0000,   0.0000,WGS 84
Reserved 1
Reserved 2
Magnetic Variation,,,E
Map Projection,(UTM) Universal Transverse Mercator,PolyCal,No,AutoCalOnly,No,BSBUseWPX,No
Point01,xy,   75,   75,in, deg,    ,        ,N,    ,        ,W, grid, 30,     446000,    4113593,N
Point02,xy, 5596,   75,in, deg,    ,        ,N,    ,        ,W, grid, 30,     483395,    4113593,N
Point03,xy, 5595, 4592,in, deg,    ,        ,N,    ,        ,W, grid, 30,     483395,    4083000,N
Point04,xy,   75, 4592,in, deg,    ,        ,N,    ,        ,W, grid, 30,     446000,    4083000,N
Point05,xy,     ,     ,in, deg,    ,        ,N,    ,        ,W, grid,   ,           ,           ,N
Point06,xy,     ,     ,in, deg,    ,        ,N,    ,        ,W, grid,   ,           ,           ,N
Point07,xy,     ,     ,in, deg,    ,        ,N,    ,        ,W, grid,   ,           ,           ,N
Point08,xy,     ,     ,in, deg,    ,        ,N,    ,        ,W, grid,   ,           ,           ,N
Point09,xy,     ,     ,in, deg,    ,        ,N,    ,        ,W, grid,   ,           ,           ,N
Point10,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point11,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point12,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point13,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point14,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point15,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point16,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point17,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point18,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point19,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point20,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point21,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point22,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point23,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point24,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point25,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point26,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point27,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point28,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point29,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Point30,xy,     ,     ,in, deg,    ,        ,,    ,        ,, grid,   ,           ,           ,
Projection Setup,,,,,,,,,,
Map Feature = MF ; Map Comment = MC     These follow if they exist
Track File = TF      These follow if they exist
Moving Map Parameters = MM?    These follow if they exist
MM0,Yes
MMPNUM,4
MMPXY,1,0,0
MMPXY,2,5671,0
MMPXY,3,5671,4667
MMPXY,4,0,4667
MMPLL,1,  -3.613981,  37.171138
MMPLL,2,  -3.181298,  37.172589
MMPLL,3,  -3.180583,  36.887659
MMPLL,4,  -3.611652,  36.886223
MM1B,6.773810
LL Grid Setup
LLGRID,No,No Grid,Yes,255,16711680,0,No Labels,0,16777215,7,1,Yes,x
Other Grid Setup
GRGRID,No,No Grid,Yes,255,16711680,No Labels,0,16777215,8,1,Yes,No,No,x
MOP,Map Open Position,0,0
IWH,Map Image Width/Height,5671,4667

MapMan

#2
June 03, 2014, 01:06:50 AM Last Edit: January 01, 1970, 01:00:00 AM by Guest
Thanks. That was really helpful. I have now successfully converted my Spanish map into Oruxmaps format and it works fine.
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