Missing geoid

tahvos

New Member
I want to use finnish FIN2005-geoid but I can't find it from J-Field. Can I import it somehow?
 

Kelly Bellis

ME PLS 2099
5PLS
FIN2005N00.png


Hi tahvos,

For starters, I don't know.

Also, if you are able to find a file format acceptable to J-Field, the manual adding of that file to your Triumph-LS may possibly be overwritten at the next update of GeoData. If you're up to a little experiment, read on.

Do you have an account at the Finnish Geodetic Institute?
If yes, then give this a try:
Visit http://coordtrans.fgi.fi/geoidModels.jsp

At that page, the geoid model is offered in (3) formats: Box, Grid and List. Which format to use? I don't know and it's about here that we might begin to wonder what other Javad softwares can import geoid models. The List format was able to be read by Justin; however, we're not out of the woods as it appears that J-Field isn't too interested in looking at ASCII type models. Instead - and I'm just guessing; playing along at home - the geoid model will need to be in some binary format. Being able to read FIN2005N00.lst into Justin is one thing, but coaxing it to export a binary form of that modeled surface will be another. At this point in just trying to think through things, I must stop and hope Vlad Prasolov will pinch hit for us.

And of course, waiting to hear from Vlad is the best answer I can give you now.

Once you've gotten that format nailed down and the file ready to go, connect your Triumph-LS to your PC using a USB cable and the WMDC program. In Windows Explorer, navigate to Computer\Compact\\\Mounted Volume\GeoData.

Please let us hear from you and how you resolve this.

Kind regards,

Kelly
 

tahvos

New Member
Dear Kelly,

Thank you for quick answer. Yes, I have an account at FGI and have already downloaded geoid model in List format ( Lat Lon Hgt). But I don't know how to convert this txt-file to binary *.bin, *.las, *.los files to Mounted Volume\GeoData folder.
 

Kelly Bellis

ME PLS 2099
5PLS
Dear Kelly,

Thank you for quick answer. Yes, I have an account at FGI and have already downloaded geoid model in List format ( Lat Lon Hgt). But I don't know how to convert this txt-file to binary *.bin, *.las, *.los files to Mounted Volume\GeoData folder.
This is where we hope to hear from Vlad Prasolov or somebody else more knowledgeable than me. I think the Moscow crew is on holiday until the 11th or 12th.

Most of my experience has been dealing with various softwares reading various geoid models and in most cases, they have either been in ASCII, or when in binary, they've been compliant with NGS formatting. But now we are looking for a bit of software to convert the ASCII to binary. It may be free or not. The solutions that I've found so far cost money and were part of a larger program (QINSy). I'll keep looking for an answer for you and will report back if there's any luck.
 

Vladimir Prasolov

Well-Known Member
JAVAD GNSS
Sorry for delay. I just returned to office. I hope to add FIN2005 soon. I have program to convert geoids to our format. I will send you the program link and description.
 

Vladimir Prasolov

Well-Known Member
JAVAD GNSS
I did convert original FIN2005N00.lst to FIN2005N00.bin. Also I compared it to values in pisteet.txt. The geoid undulations are exact. I will update GeoData today, so it could be released tomorrow after test group approval.
Custom geoid creation for user is not simple process. It includes usage of following programs:
JGeoids - for converting from some popular formats to our internal format and verifying it,
Coordinate System Editor in Justin Link for adding vertical datum,
and Justin Link itself for uploading custom geoid file to device's GeoData.
I think to reduce complications by adding custom geoid importing feature directly on device. What you think about that?

upload_2015-1-12_10-52-37.png

 

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Kelly Bellis

ME PLS 2099
5PLS
This is great Vladimir - thank you so very much, and welcome back. Hope that you had a wonderful holiday.

I had tried using Dan Roman's program, xntg, but it kept crashing even when run in XP mode. I've written to him a couple of weeks ago or so, but haven't heard back from yet.
 

Vladimir Prasolov

Well-Known Member
JAVAD GNSS
It was just started as my small project that allows uploading custom geoid into receiver. It is mostly important for hydrographic automated systems with sonic depth-finder, where GNSS receiver's nmea GGA sentences are used for coordinates with orthometric height. Later I fount that application is useful for converting geoids from various formats.
 

Kelly Bellis

ME PLS 2099
5PLS
possible issue with chrome download.PNG


I'm not sure what is the problem; however, I suspect that Chrome and its zealous security concerns has prevented me from downloading this file twice, so far. Chrome complains that it is dangerous. Maybe zipping up as .zip will work.
 
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