Topic: What is ArcGrid Metadata file?

[dfarris75]

http://map3d.wordpress.com/2007/12/19/surface-from-ned-files/

[dfarris75]

OK I got that to work out wonderfully so now if I could just figure out what was going on with the zone I think it would work great!

Now my question is, how to I take it from NAVD88 to NGVD29???

[dfarris75]

In the tutorial the guy said that the poly's would show zero elev., but the object data would be there so you could query them in and do a alter props to get them @ elev. When I look at these contours they are nothing but flat 2d poly's and have no object data attached...?

[mjfarrell]

In the tutorial the guy said that the poly's would show zero elev., but the object data would be there so you could query them in and do a alter props to get them @ elev. When I look at these contours they are nothing but flat 2d poly's and have no object data attached...?

Once you import the sdf file you will have polylines and object data attached to them, if you check the properties of one you notice it is at an elevation of “0” but the object data has the correct elevation listed. At this time save the drawing and close it out. We need to attach it to another new drawing and perform an alter-property query to alter the polylines elevation. So open a new drawing again and make sure the map task pane is open. Attach the saved drawing (the one you just saved and closed) using the map task pane. Now perform an alter-property query to set the polylines on their correct elevation

[mjfarrell]

what's cool about this question; is that NO you can NOT build the surface file directly from the NED file.
however I did learn something new in the process of discovery...

[dfarris75]

Care to share it with us Michael? :love:

[dfarris75]

I'm still lost with these. I'm trying out the NED's as well as the SRTM's. My lack of knowledge and understanding with coordinate zones obviously hinders me.

The NED is NAD83. My dwg is set up for FL83-EF (NAD83 Florida State Planes, East Zone, US Foot). Should the NED come into this file on target or what because it doesn't? Is there some other zone I need to use for the NED's?

The SRTM is WGS84, but when I go to set up my dwg there isn't one that is just WGS84. There's a category of UTM, WGS84 Datum and there's a category of World/Continental, both of which have several zones based on WGS84, but I have no idea which one to use.

Please help; educate.

[mjfarrell]

process

New MAP drawing for EACH data source
Use the MAP>>Tools>>Assign Global Coordinate System
Set the CS to match what you know about your soure(s)
Import a datasource, and Save the file for each of your data sources.


Open a NEW Map Drawing, Assign the CS you want or need to use.

use Map>>Drawings>>Define/Modify Drawing set.
Attach the file(s) you made above for each of your data sources.

When you perfom a Map>>Query, Map will (should) then perform the required transformations upon import of the queried data.

(where is my tkt to FLA?)