Correct - Tiff files don’t contain elevation data
Try get HGT data from here http://www.viewfinderpanoramas.org/dem3.html and convert to USGS DEM with 3DEM software http://www.visualizationsoftware.com/3dem Regards David Bingham, P. GEO. BG logo-smallBingham Geoscience <mailto:[email protected]> [email protected] <http://www.binghamgeophysics.com/> www.binghamgeophysics.com From: edcunion <[email protected]> [mailto:[email protected]] Sent: Tuesday, February 24, 2015 3:44 PM To: Geosoft Oasis montaj and Target Subject: Re: [geonet] DTM grid for topographical correction Rafael, >From experience, please correct me if this is inaccurate, geotifs don't >contain the topo info needed in the Z coordinate for the terrain corrections, >whereas a Geosoft grid does. Converting geotifs to Geosoft grids also doesn't >supply the topo Z coordinate needed. If free easily obtainable SRTM topography (in Geosoft GRD format) is not accurate enough for your terrain corrections, You may have to eyeball manually digitize, using Geosoft or some other software, any visible topo contour numbers to an XYZ coordinate file, and then grid this XYZ file using Geosoft to create the necessary elevation grid Geosoft uses for gravity terrain corrections. You'd generate accurate XY coordinates this way, and then populate the Z column with the eyeball determined numbers. The XY and Z coordinates all need to be accurately geo-located on the elevation grid prior to terrain correction. Geotifs often have accurate XY coordinates, regular Tifs might have to be geo-located first to the projection system used for your area. On Tuesday, February 24, 2015 11:51 AM, "Rafael Rodriguez <[email protected]>" <[email protected]> wrote: Hi everybody: It is possible take one dtm in tif format for topographical correction? Or what i do for make one tif image for make the dtm and then make the topographical correction i geosoft? Best regards Rafael Rodriguez Instituto Nacional de Geologia y Mineria Caracas, Venezuela --- Forum archives can be accessed here: http://lyris.geosoft.com/read/?forum=geonet <http://lyris.geosoft.com/read/?fourm=geonet> You are currently subscribed to geonet as: [email protected]. To subscribe or unsubscribe from any of our forums, select the User Forum selection on the Geosoft Community page: http://www.geosoft.com/support/community/forums/register/ --- Forum archives can be accessed here: http://lyris.geosoft.com/read/?forum=geonet <http://lyris.geosoft.com/read/?fourm=geonet> You are currently subscribed to geonet as: [email protected]. To subscribe or unsubscribe from any of our forums, select the User Forum selection on the Geosoft Community page: http://www.geosoft.com/support/community/forums/register/ --- Forum archives can be accessed here: http://lyris.geosoft.com/read/?forum=geonet You are currently subscribed to geonet as: [email protected]. To subscribe or unsubscribe from any of our forums, select the User Forum selection on the Geosoft Community page: http://www.geosoft.com/support/community/forums/register/
