Jump to content

 
Photo

problem with projection while exporting to arcgis

- - - - -

  • Please log in to reply
4 replies to this topic

#1
gregory

gregory

    Key Contributor

  • Validated Member
  • PipPipPip
  • 96 posts
  • Gender:Male
  • Location:Cracow
  • Poland

Hello,
I posted that topic http://forum.manifol.../forum/t57588.0 and waiting for reply, i will try a lucky here, so:

I would like to convert SRTM file *.hgt to bil format to open the last in arcmap. The manifold opens correctly SRTM showing me the hgt is in Lat/Long projection. It also exports it correctly to *.bil. It comes to problem when i want to open in arcgis bil . It load it but shows corrdinates like 000'19,734'' E 000'49,261 "N and so on. I checked datum and projection under arcmap. Seems to be the same like in manifold (lat/long). Also projection assiging in arcmap to (lat/long) doesnt change the display. In that case is intelligibly that the rest of the data doesn't fit.

To check what is going on i also opened project that im working on in arcmap with other projection (UTM 34N) but with the same datum, to check how will the exported *.bil behave "on the fly" while adding. The msg i got is like "GCS_Unknown datum based upon the GRS ellipsoid" ... alingment and accuracy problems may arise...

There is transformation under the menu which could let me convert it correctly but i cannot find any transformation to do it correctly. The SRTM file comes from

http://www.viewfinde...s.org/dem3.html and i think it may be a problem , cause there is no problem with any SRTM i got from cgiar or any other official sources.
I know i could try to open hgt directly in arcmap without using manifold creating text file with info about projection, but i want to learn as much manifold as I can and this is one of first problem with unterstanding its behave.

Many thanks for any comment and suggestion how to deal with it

regards

Gregory

#2
gregory

gregory

    Key Contributor

  • Validated Member
  • PipPipPip
  • 96 posts
  • Gender:Male
  • Location:Cracow
  • Poland

Hi,

It was easier I could suspect. All i had to do was to delete *.prj, reimport bil to arcgis, reproject to (lat/long).
Thanks to AdamW.
http://forum.manifold.net/forum/t57588

gregory

#3
rudy

rudy

    Ultimate Contributor

  • Validated Member
  • PipPipPipPipPipPip
  • 754 posts
  • Gender:Male
  • Location:Canada
  • Canada

I've always found it easier to work with SRTM files in Manifold than in ArcGIS.

#4
ProMapper

ProMapper

    Master Contributor

  • Validated Member
  • PipPipPipPip
  • 216 posts
  • Gender:Female
  • Location:India
  • Interests:promapper@gmail.com
  • India

I've always found it easier to work with SRTM files in Manifold than in ArcGIS.

Global mapper is another versatile software for SRTM data conversion. However if one orders a DVD of SRTM data it is sent in .bil format.

#5
Charlie Frye

Charlie Frye

    Master Contributor

  • Validated Member
  • PipPipPipPip
  • 112 posts
  • Gender:Male
  • Location:Redlands, CA
  • Interests:Base map design/data model, political/election maps; use of historical maps for modern GIS analysis
  • United States

The .hgt files which can be used by ArcGIS if you change the .hgt to .bil and create a header file.

There’s actually a nice website that will create the contents for the header file for you, and you just need to paste it in to a blank text document and save it as <imagename>.hdr, where <imagename> is the same as the .bil file. Here’s that site:

http://www.unc.edu/~...rtmheader.shtml
Charlie Frye
Chief Cartographer
Software Products Department
ESRI, Redlands, California




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

-->