> ----------
> From: Ilwis Support
> Sent: Tuesday, October 05, 1999 1:29:36 PM
> To: Ilwis-List
> Cc: '[EMAIL PROTECTED]'; '[EMAIL PROTECTED]'
> Subject: RE: How to keep coordinates !
> Auto forwarded by a Rule
>
Carlos,
The shift you notice after glueing the segment (sub-)maps is not caused by
malfunctioning of the GlueSeg operation.
The shift can be explained by the fact that ILWIS is internally using a
different resolution for the segment maps. Internally, ILWIS stores
coordinates of segments in 2 shorts (and uses a translation). This means
that the area of interest is stored in a maximum of 32000 units. The unit
size depends on the boundaries (map extend) of the segment map. Smaller
boundary limits mean smaller unit sizes and thus higher resolution. To avoid
the shift after glueing, use the same boundary coordinates for all submaps
AND the final combined map. By using the same boundaries, the same unit size
is used for all maps.
Regards,
Jelger
-------------------------------------------
Jelger Kooistra, ILWIS Support Officer
ITC - ILWIS Department
PO Box 6, 7500 AA Enschede, The Netherlands
phone: +31 53 4874217 fax: +31 53 4874484
e-mail: [EMAIL PROTECTED]
http://www.itc.nl/ilwis/dev/support
-------------------------------------------
> ----------
> From: Clas[SMTP:[EMAIL PROTECTED]]
> Sent: Monday, September 27, 1999 4:13:54 PM
> To: [EMAIL PROTECTED]
> Subject: How to keep coordinates !
> Auto forwarded by a Rule
>
> Hello!
>
> I would like to know if someone else had this problem with Ilwis and if
> he/she solved:
>
> I digitized on screen parcel's boundaries using as map boundaries only the
> coordinates I need to cover each block. So, I ended with as many files as
> blocks. But when I tried to have a map of the whole city, using GLUESEG,
> the new map does not match to the original ones, having a shift of 5-10
> cm. I tried using the clip boundary option but is also wrong, giving me a
> thir map.
>
> To do things worst, using as a base map the original parcel's boundaries,
> we digitized buildings, and when we glue them, the new map, for the whole
> city,have a different shift of the map of boundaries.
>
> You can realize that if you want to make an operation using this two maps
> we will end with slivers representing buildings on the streets.
>
> Is anybody facing the same problems ?
> Please help me with your work around.
> -------------------------------------------------------------------
> Centro de Levantamientos Aerospaciales y Aplicaciones SIG para el
> Desarrollo
> Sostenible de los Recursos Naturales. - CLAS -
> Edificio Multiacademico 2do piso. UMSS
> Casilla 5294
> Tel/Fax +591 - (0)42-56551
> E-mail: [EMAIL PROTECTED]
> http://www.umss.edu.bo
> Cochabamba - Bolivia
