Projection bug ?

PoWa · July 2011

Hi,

I noticed a bug:
if I add a raster map (Scan25 IGN in .tif) with a raster ortho (BdOrtho IGN in .ecw), I find myself with a lag.
I compared with other software: Mapinfo, i used the function of Bboxes in GlobalMapper to create area features and add this vector in mapinfo , the lag can be observed easily on the same mapfile (see picture).

I'm working in Lambert93

mapdecal.jpg

In red the real coordinates
In blue GlobalMapper's coordinates.

The result in GlobalMapper (see the highway+bridge) :

glut.jpg

I havent bug when i drape my mnt (lidar .asc) with orthophoto.

My version is GM v12.02 b07211 (the lastest)

thank you in advance

global_mapper · July 2011

It looks like maybe the datum for one layer is incorrect. Are you being prompted to select the projection/datum for any of the layers when loading?

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

PoWa · July 2011

All my layers are in Lambert93 with RGF93 datum, i checked this before posting.

The metadata :

Attachment not found.

It's strange, if i open my map catalogue (build by IGN : a big ecw with algorythm), the projection is good (i can drape my MNT from globalmapper catalogue) but if i open directly one ecw from this IGN catalogue or one rastermap, they are wrong (same metadata => the googlemap's datum is wrong

??).

PoWa · July 2011

The good attachment :rolleyes:

metadata.jpg

http://img29.imageshack.us/img29/351/metadata.png

global_mapper · July 2011

It does look like the datum is coming in differently for some of the ECW files, one as just a GRS80 ellipsoid (basically the same as WGS84) and the other as the Google Maps datum (much different). Can you scroll down one line in the metadata for the ECW files so I can see what datum name is used in the ECW file itself. This is right below the PROJ_NAME line.

Note that you can correct the projection/datum interpretation for the layer on the Projection tab of the Options dialog for the layer.

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

PoWa · July 2011

Thanks Mike,
I was a previous user of globalmapper

, so I used my old version (v11) to load my workspace (mnt+ortho+map) and check (before i had not this problem of projection). The same workspace used on the v12 (same parameters logically), it works perfectly, no problem. If i load this workspace in my v12, there is this problem. I check the metadata to compare, there is a slightly difference in the datum. So i go to my map's option/projection to change, parameters are same (RGF93, no change)

but in metadata, the same file has metadata different (datum google... see the quote). I don't understand

I save my projection of v11 in projection file .prj to load in v12, doesn't work.

For your information :

FILENAME=ECW
DESCRIPTION=44-2004-0350-6700-LA93-C07.ECW
UPPER LEFT X=350000.000
UPPER LEFT Y=6700000.000
LOWER RIGHT X=355000.000
LOWER RIGHT Y=6695000.000
WEST LONGITUDE=1.63514291° W
NORTH LATITUDE=47.31046342° N
EAST LONGITUDE=1.56525117° W
SOUTH LATITUDE=47.26290672° N
PROJ_DESC=Lambert-93 / RGF-93 / meters
PROJ_DATUM=RGF-93
PROJ_UNITS=meters
EPSG_CODE=2154
COVERED AREA=25000004 sq m
NUM COLUMNS=10000
NUM ROWS=10000
NUM_BANDS=3
PIXEL WIDTH=0.5 meters
PIXEL HEIGHT=0.5 meters
BIT_DEPTH=24
PROJ_NAME=LMFRAN93
DATUM_NAME=RGF93
TARGET_COMPRESSION=1:7

My map
In my v11

FILENAME=SCAN25_44.gmc
DESCRIPTION=SCAN25_44
UPPER LEFT X=270000.000
UPPER LEFT Y=6760000.000
LOWER RIGHT X=410000.000
LOWER RIGHT Y=6640000.000
WEST LONGITUDE=2.74899521° W
NORTH LATITUDE=47.87624131° N
EAST LONGITUDE=0.80366966° W
SOUTH LATITUDE=46.72196729° N
PROJ_DESC=Lambert-93 / WGS84 / meters
PROJ_DATUM=WGS84
PROJ_UNITS=meters
COVERED AREA=16800002911 sq m
BIT_DEPTH=24
MAPS IN CATALOG=104

In my v12 :

FILENAME=SCAN25_44.gmc
DESCRIPTION=SCAN25_44
UPPER LEFT X=270000.000
UPPER LEFT Y=6760000.000
LOWER RIGHT X=410000.000
LOWER RIGHT Y=6640000.000
WEST LONGITUDE=2.75940352° W
NORTH LATITUDE=47.87457780° N
EAST LONGITUDE=0.81043218° W
SOUTH LATITUDE=46.72115715° N
PROJ_DESC=Lambert-93 / GOOGLE / meters
PROJ_DATUM=GOOGLE MAPS (SPHERE RADIUS 6378137)
PROJ_UNITS=meters
COVERED AREA=16800002911 sq m
NUM_BANDS=1
BIT_DEPTH=24
MAPS IN CATALOG=104

I hope this helps clarify the "mystery"

global_mapper · July 2011

It looks like the datum in your map catalog is what is set to Google Maps. Can you post your .gmc file here so that I can take a look at it? The datum is stored right in the .gmc file itself.

Thanks,

Mike

PoWa · July 2011

Thanks Mike for the tip

.

In my .gmc

<projection name="LAMBERT_93_ZONE1_GOOGLE_MAPS_SPHERE_RADIUS_6378137">
Projection Lambert-93
Datum D_WGS_1984_MAJOR_AUXILIARY_SPHERE
Zunits NO
Units METERS
Zone 1
Xshift 0.000000
Yshift 0.000000
Parameters
</projection>

I replaced by (from my other catalogue)

<projection name="LAMBERT_93_ZONE1_RGF-93">
Projection Lambert-93
Datum RGF-93
Zunits NO
Units METERS
Zone 1
Xshift 0.000000
Yshift 0.000000
Parameters
</projection>

+ <prj_name>LAMBERT_93_ZONE1_RGF-93</prj_name> in <map>

Now it's works \o/

I do not understand why this setting was in the catalog (I used the same procedure as usual). I try to create a new catalogue to test, by default, this setting (datum D_WGS_1984_MAJOR_AUXILIARY_SPHERE) is used (not RGF-93). When i tried to modify the setting, the datum RGF-93 was selected (see my previous posts).

Mystery

?

global_mapper · July 2011

The projection/datum used in the catalog should default to that of the first file added to the map catalog. What is the projection/datum of the first file that you added. Can you provide a sample file here or to support@globalmapper.com?

Thanks,

Mike

mtb · July 2011

Hi,

I observe a very similar bug... I have a workspace which contains
a) some geotiffs and DEMs (also geotiff) in Gauss Krueger Germany with Potsdam/DHDN
b) several gpx-files (gps track logs).

Everything works (displays) fine in GM11 and GM 12.02 (up to build b062211!). However with b072211 I see a displacement of about 100 to 200 meters between the gpx-files and the geotiff files. I don't now if there was a build between these dates, but maybe this helps to find the bug.

Best regards,
mtb

global_mapper · July 2011

That is unexpected! Can you provide a sample workspace that demonstrates this so that I can investigate? You can email to support@globalmapper.com or if it's large FTP it to ftp.globalmapper.com with a username of 'upload' and a password of 'upload'.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

mtb · July 2011

I have sent two files to you email address.

regards,
mtb

global_mapper · July 2011

mtb,

Thanks for the files, it looks like a change made to Bursa-Wolfe transformations inadvertantly broke some of the datum conversions. I have placed a new build at http://www.globalmapper.com/global_mapper12.zip with the change for you to try. Simply download that file and extract the contents into your existing v12.xx installation folder to give it a try. If you are using the 64-bit v12 version there is a new build at http://www.globalmapper.com/global_mapper12_64bit.zip .

Let me know if I can be of further assistance.

Thanks,

Mike
Global Mapper Support
support@globalmapper.com

mtb · July 2011

Thanks, Mike.

Everything works as expected with the new build.

Best regards,
mtb

Projection bug ?

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