[Therion] Combining caves using different co-ordinate systems

[Martin Budaj]

Hi,

the problem is in the Proj4 internal definition of EPSG:25830, which
doesn't specify any geodetic datum or parameters of transformation to
wgs84 datum.

On the other hand, eur79z30 definition in therion specifies
transformation parameters (using +towgs84 keyword).

If Proj4 calculates the transformation beetween coordinate systems and
either source or target system is missing datum specification (using
either +datum, +towgs84 or +nadgrids parameters), the datum
transformation is silently skipped (see the third bullet in
http://trac.osgeo.org/proj/wiki/FAQ#HowdoIdebugproblemswithNAD27NAD83datumshifting)
resulting in positioning errors.

In your dataset, transformation from EPSG:25830 to any cs using other
geodetic datum may be off by a few dozen meters. Coincidentally, the
datum shift between EPSG:25830 (ETRS89 datum) and UTM30 (WGS84 datum)
is really minimal (see e.g. http://www.killetsoft.de/t_1009_e.htm), so
the result in Therion seemed to be correct when you selected UTM30 as
an output cs.

If output cs uses other datum than WGS84 or ETRS89, the difference
will be substantial, as was in your examples.

The issue can be fixed by changing Proj4 definition of EPSG:25830 from

+proj=utm +zone=30 +ellps=GRS80 +units=m +no_defs

to

+proj=utm +zone=30 +ellps=GRS80 +towgs84=0,0,0 +units=m +no_defs

You can do this in therion.ini file using cs-def command.

Martin


On Tue, Sep 23, 2014 at 4:35 PM, Footleg  wrote:
> Yes, adding that different cs declaration to my thconfig file does
> solve the problem.
>
> Thank you for this work around.
>
> Footleg
>
> On 22 September 2014 17:27, Stacho Mudrak  wrote:
>> Something goes definitely wrong here...
>>
>> If no CS is defined in thconfig file, therion uses first CS that it founds
>> as output CS - therefore if you reverse input files, results change.
>>
>> It looks to me, that transformations to coordinate systems you are using do
>> not work as expected. Unfortunatelly, I have no idea why it is like that -
>> it needs some more sophisticated debugging, but using WGS84/UTM as output CS
>> seems to work fine - see attached file.
>>
>> Does it solve your problem?
>>
>> S.
>>
>> On 20 September 2014 23:12, Bruce  wrote:
>>>
>>> Hmm, Seems you are right that it is wrong.
>>> I tried adding explicit select statements to the
>>> thconfig-both_csconfig.thc
>>> and changing the position of the cs within the file, with no change in
>>> behaviour.
>>> Looks like a bug to me.
>>>
>>> Only difference that I can see with how I use it is that I am using
>>> lat-long
>>> (sometimes but not always) and two variants of an EPSG specification
>>> (which
>>> if exhibited same behaiour would give 1000's km error), whereas you have
>>> not
>>> used an EPSG code for eur79z30.
>>>
>>>
>>> Clutching at straws...
>>> Does eur79z30 have an EPSG code, and if it does, does using it's EPSG code
>>> in place of eur79z30 fix the behaviour?
>>>
>>> Bruce
>>>
>>> -Original Message-
>>> From: therion-bounces at speleo.sk [mailto:therion-bounces at speleo.sk] On
>>> Behalf
>>> Of Footleg
>>> Sent: Saturday, 20 September 2014 11:55 p.m.
>>> To: List for Therion users
>>> Subject: Re: [Therion] Combining caves using different co-ordinate systems
>>>
>>> I have checked that both my survey files have date and cs declarations
>>> inside centreline blocks. Each file generates the correct position when I
>>> generate a KML from either file alone.
>>> Next I tried to add a cs statement in my thconfig file. This appears to
>>> over-ride the cs I declared in the centreline block. So if I put a
>>> different
>>> cs declaration in the thconfig file to the cs declared in the survey data
>>> file, then this results in the kml output putting the cave in the wrong
>>> place.
>>>
>>> I have created a bear bones set of examples (attached). The cave should be
>>> on the edge of the open grass area and trees.
>>>
>>> thconfig-eur79Only.thc  Puts the cave declared with Eur79 datum in the
>>> correct place.
>>> thconfig-EPSGOnly.thc Puts the cave declared with EPSG:25830 datum in the
>>> correct place.
>>>
>>> thconfig-eur79csconfig.thc Declares the cave with Eur79 but specifies
>>> EPSG:25830 in the thconfig, and the cave now appears in the wrong place.
>>>
>>> The other files show various ways of including both caves, and they are
>>> rendered always with one in the correct place and one in the wrong place.
>>>
>>> Footleg
>>>
>>> ___
>>> Therion mailing list
>>> Therion at speleo.sk
>>> http://mailman.speleo.sk/mailman/listinfo/therion
>>
>>
>>
>> ___
>> Therion mailing list
>> Therion at speleo.sk
>> http://mailman.speleo.sk/mailman/listinfo/therion
>>
> ___
> Therion mailing list
> Therion at speleo.sk
> http://mailman.speleo.sk/mailman/listinfo/therion

[Therion] Combining caves using different co-ordinate systems

[Stacho Mudrak]

Something goes definitely wrong here...

If no CS is defined in thconfig file, therion uses first CS that it founds
as output CS - therefore if you reverse input files, results change.

It looks to me, that transformations to coordinate systems you are using do
not work as expected. Unfortunatelly, I have no idea why it is like that -
it needs some more sophisticated debugging, but using WGS84/UTM as output
CS seems to work fine - see attached file.

Does it solve your problem?

S.

On 20 September 2014 23:12, Bruce  wrote:

> Hmm, Seems you are right that it is wrong.
> I tried adding explicit select statements to the thconfig-both_csconfig.thc
> and changing the position of the cs within the file, with no change in
> behaviour.
> Looks like a bug to me.
>
> Only difference that I can see with how I use it is that I am using
> lat-long
> (sometimes but not always) and two variants of an EPSG specification (which
> if exhibited same behaiour would give 1000's km error), whereas you have
> not
> used an EPSG code for eur79z30.
>
>
> Clutching at straws...
> Does eur79z30 have an EPSG code, and if it does, does using it's EPSG code
> in place of eur79z30 fix the behaviour?
>
> Bruce
>
> -Original Message-
> From: therion-bounces at speleo.sk [mailto:therion-bounces at speleo.sk] On
> Behalf
> Of Footleg
> Sent: Saturday, 20 September 2014 11:55 p.m.
> To: List for Therion users
> Subject: Re: [Therion] Combining caves using different co-ordinate systems
>
> I have checked that both my survey files have date and cs declarations
> inside centreline blocks. Each file generates the correct position when I
> generate a KML from either file alone.
> Next I tried to add a cs statement in my thconfig file. This appears to
> over-ride the cs I declared in the centreline block. So if I put a
> different
> cs declaration in the thconfig file to the cs declared in the survey data
> file, then this results in the kml output putting the cave in the wrong
> place.
>
> I have created a bear bones set of examples (attached). The cave should be
> on the edge of the open grass area and trees.
>
> thconfig-eur79Only.thc  Puts the cave declared with Eur79 datum in the
> correct place.
> thconfig-EPSGOnly.thc Puts the cave declared with EPSG:25830 datum in the
> correct place.
>
> thconfig-eur79csconfig.thc Declares the cave with Eur79 but specifies
> EPSG:25830 in the thconfig, and the cave now appears in the wrong place.
>
> The other files show various ways of including both caves, and they are
> rendered always with one in the correct place and one in the wrong place.
>
> Footleg
>
> ___
> Therion mailing list
> Therion at speleo.sk
> http://mailman.speleo.sk/mailman/listinfo/therion
>
-- next part --
An HTML attachment was scrubbed...
URL: 
<http://mailman.speleo.sk/pipermail/therion/attachments/20140922/53e502af/attachment.html>
-- next part --
A non-text attachment was scrubbed...
Name: thconfig-both-utm.thc
Type: application/octet-stream
Size: 164 bytes
Desc: not available
URL: 
<http://mailman.speleo.sk/pipermail/therion/attachments/20140922/53e502af/attachment.obj>

[Therion] Combining caves using different co-ordinate systems

[Bruce]

Hmm, Seems you are right that it is wrong.
I tried adding explicit select statements to the thconfig-both_csconfig.thc
and changing the position of the cs within the file, with no change in
behaviour.
Looks like a bug to me.

Only difference that I can see with how I use it is that I am using lat-long
(sometimes but not always) and two variants of an EPSG specification (which
if exhibited same behaiour would give 1000's km error), whereas you have not
used an EPSG code for eur79z30.


Clutching at straws...
Does eur79z30 have an EPSG code, and if it does, does using it's EPSG code
in place of eur79z30 fix the behaviour?

Bruce

-Original Message-
From: therion-bounces at speleo.sk [mailto:therion-boun...@speleo.sk] On Behalf
Of Footleg
Sent: Saturday, 20 September 2014 11:55 p.m.
To: List for Therion users
Subject: Re: [Therion] Combining caves using different co-ordinate systems

I have checked that both my survey files have date and cs declarations
inside centreline blocks. Each file generates the correct position when I
generate a KML from either file alone.
Next I tried to add a cs statement in my thconfig file. This appears to
over-ride the cs I declared in the centreline block. So if I put a different
cs declaration in the thconfig file to the cs declared in the survey data
file, then this results in the kml output putting the cave in the wrong
place.

I have created a bear bones set of examples (attached). The cave should be
on the edge of the open grass area and trees.

thconfig-eur79Only.thc  Puts the cave declared with Eur79 datum in the
correct place.
thconfig-EPSGOnly.thc Puts the cave declared with EPSG:25830 datum in the
correct place.

thconfig-eur79csconfig.thc Declares the cave with Eur79 but specifies
EPSG:25830 in the thconfig, and the cave now appears in the wrong place.

The other files show various ways of including both caves, and they are
rendered always with one in the correct place and one in the wrong place.

Footleg

[Therion] Combining caves using different co-ordinate systems

[Footleg]

I have checked that both my survey files have date and cs declarations
inside centreline blocks. Each file generates the correct position
when I generate a KML from either file alone.
Next I tried to add a cs statement in my thconfig file. This appears
to over-ride the cs I declared in the centreline block. So if I put a
different cs declaration in the thconfig file to the cs declared in
the survey data file, then this results in the kml output putting the
cave in the wrong place.

I have created a bear bones set of examples (attached). The cave
should be on the edge of the open grass area and trees.

thconfig-eur79Only.thc  Puts the cave declared with Eur79 datum in the
correct place.
thconfig-EPSGOnly.thc Puts the cave declared with EPSG:25830 datum in
the correct place.

thconfig-eur79csconfig.thc Declares the cave with Eur79 but specifies
EPSG:25830 in the thconfig, and the cave now appears in the wrong
place.

The other files show various ways of including both caves, and they
are rendered always with one in the correct place and one in the wrong
place.

Footleg
-- next part --
A non-text attachment was scrubbed...
Name: DualCSTests.zip
Type: application/zip
Size: 6821 bytes
Desc: not available
URL: 

[Therion] Combining caves using different co-ordinate systems

[Xavier Pennec]

Could it be that it comes from cs specifications in the same centerline 
environment?

I have been using multiple datums (e.g lat-long, UTM, old and new 
lambert coordinate systems for France) for fixing coordinates in a 
system of multiple caves without any problem. However, I believe that I 
have a single cs statement per centerline.  Indeed, at some point I 
discovered that the equal statements were now working properly outside 
the centerline environment, so that I centerlined individually all my 
pieces of survey, even in the same survey.

My 2 bits

Xavier




Le 19/09/2014 23:10, Bruce a écrit :
> We have been using multiple coordinate systems for a number of years, 
> and it seems to work perfectly.
> We mix and match at will between lat-long, NZMG and NZTM (ie old and 
> new datums) within the same cave survey and between cave surveys.
> So, Footleg, unless you have other reasons to do so, there is no need 
> to convert your old datum coords to new datum coords.
> There seem to be a couple of rules to keep things working smoothly.  
> Have a look at Therion Book pg 14 and 46-47 and keep in mind 
> the distinction between input and output.
>
> 1.
> Each centerline with fix statement(s) should have a date and cs
> specification (prior to the fix I think).
> 2.
> So that you can be sure of the cs applied to the outputs, specify
> the output cs that you want in the th-config (not in a layout).
> 3.
> I have avoided using cs in layout, as, even if Therion is
> consistent in the way it applies it, in the situation where there
> are multiple coordinate systems in use, it is not abundantly clear
> to a user which cs will be used, for example where
> some centrelines have no explicit cs or for the output.  (Although
> reading Therion Book pg 47, maybe that is for Atlas outputs - been
> a while, I forget).
>
> Now that we have output variables in 5.3.15 that echo the cs that has 
> been used for output, it will be possible to have this stamped in the 
> pdf header.  I have a 'proof that it works' layout drafted up, and one 
> day I will make a modular set of layouts to make it readily useable
> The first file embedded on this page 
> http://therion.speleo.sk/wiki/doku.php/templates
> (ie 
> http://therion.speleo.sk/wiki/lib/exe/fetch.php/templates:thconfig-templatesimple.txt)
> shows how I use it in a th-config file.
> Bruce
>
> 
> *From:* therion-bounces at speleo.sk [mailto:therion-bounces at speleo.sk] 
> *On Behalf Of *Footleg
> *Sent:* Saturday, 20 September 2014 4:13 a.m.
> *To:* List for Therion users
> *Subject:* Re: [Therion] Combining caves using different co-ordinate 
> systems
>
> I had put one cave using a cs and gps fix coordinates into one survey 
> block in a .th file. Then a second cave using a different cs and gps 
> fix coordinates in a second .th file.
>
> My project then uses a master.th <http://master.th> file which inputs 
> both of these. If I run my config on either of the individual files 
> then they appear at the correct place on Google Earth from an output 
> kml file. If I include both caves then they appear in different 
> places. The one I include first is in the correct place. If I swap the 
> order they appear in the master.th <http://master.th> file then this 
> confirms the first one is alway put in the correct place, and the 
> second is positioned using the cs of the first one.
>
> The same in a lox model file (except I cannot confirm which is 
> correct, but I see them in different places when I give them the same 
> entrance location to test this).
>
> Footleg
>
> On 19 Sep 2014 14:33, "Andrew Atkinson"  <mailto:andrew at wotcc.org.uk>> wrote:
>
> You can use cs in config file, either inside layout, or outside
> layout (most likely what you want to do) to control the output
> co-ordinate system, which I think is what you are trying to do?
>
> Andrew
>
> On 19 Sep 2014 14:00, "Footleg"  <mailto:drfootleg at gmail.com>> wrote:
>
> I have been converting a project from an old datum to a more
> recent
> one following the issuing of new maps using the newer datum.
> So all my
> entrance GPS coordinates changed. I updated the cs statements
> in my
> survey data files and my KML output is still in the correct
> place. So
> all was looking good. Then I discovered that if I include a
> survey in
> the old cs with one using the new cs then Therion appears to treat
> both caves as having the same cs. Whichever cs is used by the
> 

[Therion] Combining caves using different co-ordinate systems

[Bruce]

We have been using multiple coordinate systems for a number of years, and it
seems to work perfectly.
We mix and match at will between lat-long, NZMG and NZTM (ie old and new
datums) within the same cave survey and between cave surveys.
So, Footleg, unless you have other reasons to do so, there is no need to
convert your old datum coords to new datum coords.

There seem to be a couple of rules to keep things working smoothly.  Have a
look at Therion Book pg 14 and 46-47 and keep in mind the distinction
between input and output.  

1.  

Each centerline with fix statement(s) should have a date and cs
specification (prior to the fix I think).
2.  

So that you can be sure of the cs applied to the outputs, specify
the output cs that you want in the th-config (not in a layout).
3.  

I have avoided using cs in layout, as, even if Therion is consistent
in the way it applies it, in the situation where there are multiple
coordinate systems in use, it is not abundantly clear to a user which cs
will be used, for example where some centrelines have no explicit cs or for
the output.  (Although reading Therion Book pg 47, maybe that is for Atlas
outputs - been a while, I forget).

Now that we have output variables in 5.3.15 that echo the cs that has been
used for output, it will be possible to have this stamped in the pdf header.
I have a 'proof that it works' layout drafted up, and one day I will make a
modular set of layouts to make it readily useable

The first file embedded on this page
http://therion.speleo.sk/wiki/doku.php/templates
(ie
http://therion.speleo.sk/wiki/lib/exe/fetch.php/templates:thconfig-templates
imple.txt)
shows how I use it in a th-config file.

Bruce


  _  

From: therion-bounces at speleo.sk [mailto:therion-boun...@speleo.sk] On Behalf
Of Footleg
Sent: Saturday, 20 September 2014 4:13 a.m.
To: List for Therion users
Subject: Re: [Therion] Combining caves using different co-ordinate systems



I had put one cave using a cs and gps fix coordinates into one survey block
in a .th file. Then a second cave using a different cs and gps fix
coordinates in a second .th file.

My project then uses a master.th file which inputs both of these. If I run
my config on either of the individual files then they appear at the correct
place on Google Earth from an output kml file. If I include both caves then
they appear in different places. The one I include first is in the correct
place. If I swap the order they appear in the master.th file then this
confirms the first one is alway put in the correct place, and the second is
positioned using the cs of the first one.

The same in a lox model file (except I cannot confirm which is correct, but
I see them in different places when I give them the same entrance location
to test this).

Footleg

On 19 Sep 2014 14:33, "Andrew Atkinson"  wrote:


You can use cs in config file, either inside layout, or outside layout (most
likely what you want to do) to control the output co-ordinate system, which
I think is what you are trying to do?

Andrew

On 19 Sep 2014 14:00, "Footleg"  wrote:


I have been converting a project from an old datum to a more recent
one following the issuing of new maps using the newer datum. So all my
entrance GPS coordinates changed. I updated the cs statements in my
survey data files and my KML output is still in the correct place. So
all was looking good. Then I discovered that if I include a survey in
the old cs with one using the new cs then Therion appears to treat
both caves as having the same cs. Whichever cs is used by the first
included cave is applied to subsequent caves too. Is there a way to
deal with this?

Footleg
___
Therion mailing list
Therion at speleo.sk
http://mailman.speleo.sk/mailman/listinfo/therion



___
Therion mailing list
Therion at speleo.sk
http://mailman.speleo.sk/mailman/listinfo/therion



-- next part --
An HTML attachment was scrubbed...
URL: 
<http://mailman.speleo.sk/pipermail/therion/attachments/20140920/840b0c00/attachment.html>

[Therion] Combining caves using different co-ordinate systems

[Footleg]

I had put one cave using a cs and gps fix coordinates into one survey block
in a .th file. Then a second cave using a different cs and gps fix
coordinates in a second .th file.

My project then uses a master.th file which inputs both of these. If I run
my config on either of the individual files then they appear at the correct
place on Google Earth from an output kml file. If I include both caves then
they appear in different places. The one I include first is in the correct
place. If I swap the order they appear in the master.th file then this
confirms the first one is alway put in the correct place, and the second is
positioned using the cs of the first one.

The same in a lox model file (except I cannot confirm which is correct, but
I see them in different places when I give them the same entrance location
to test this).

Footleg
On 19 Sep 2014 14:33, "Andrew Atkinson"  wrote:

> You can use cs in config file, either inside layout, or outside layout
> (most likely what you want to do) to control the output co-ordinate system,
> which I think is what you are trying to do?
>
> Andrew
> On 19 Sep 2014 14:00, "Footleg"  wrote:
>
>> I have been converting a project from an old datum to a more recent
>> one following the issuing of new maps using the newer datum. So all my
>> entrance GPS coordinates changed. I updated the cs statements in my
>> survey data files and my KML output is still in the correct place. So
>> all was looking good. Then I discovered that if I include a survey in
>> the old cs with one using the new cs then Therion appears to treat
>> both caves as having the same cs. Whichever cs is used by the first
>> included cave is applied to subsequent caves too. Is there a way to
>> deal with this?
>>
>> Footleg
>> ___
>> Therion mailing list
>> Therion at speleo.sk
>> http://mailman.speleo.sk/mailman/listinfo/therion
>>
>
> ___
> Therion mailing list
> Therion at speleo.sk
> http://mailman.speleo.sk/mailman/listinfo/therion
>
>
-- next part --
An HTML attachment was scrubbed...
URL: 

[Therion] Combining caves using different co-ordinate systems

[Andrew Atkinson]

You can use cs in config file, either inside layout, or outside layout
(most likely what you want to do) to control the output co-ordinate system,
which I think is what you are trying to do?

Andrew
On 19 Sep 2014 14:00, "Footleg"  wrote:

> I have been converting a project from an old datum to a more recent
> one following the issuing of new maps using the newer datum. So all my
> entrance GPS coordinates changed. I updated the cs statements in my
> survey data files and my KML output is still in the correct place. So
> all was looking good. Then I discovered that if I include a survey in
> the old cs with one using the new cs then Therion appears to treat
> both caves as having the same cs. Whichever cs is used by the first
> included cave is applied to subsequent caves too. Is there a way to
> deal with this?
>
> Footleg
> ___
> Therion mailing list
> Therion at speleo.sk
> http://mailman.speleo.sk/mailman/listinfo/therion
>
-- next part --
An HTML attachment was scrubbed...
URL: 

[Therion] Combining caves using different co-ordinate systems

[Footleg]

I have been converting a project from an old datum to a more recent
one following the issuing of new maps using the newer datum. So all my
entrance GPS coordinates changed. I updated the cs statements in my
survey data files and my KML output is still in the correct place. So
all was looking good. Then I discovered that if I include a survey in
the old cs with one using the new cs then Therion appears to treat
both caves as having the same cs. Whichever cs is used by the first
included cave is applied to subsequent caves too. Is there a way to
deal with this?

Footleg