Opening Dem's in Microdem (dem's don't open)

[theedge2k]

Hello i am following the link below, but i am having problems opening any dem file. I have downloaded the dem's the GIS website. When i try to open the dem's open a small 1/4 by 1/4 window in the upper left cornet of microdem. I hav tried to drag the corners to make the window bigger but nothing happens. Can someone tell where i went wrong.

Here is the link for the steps i have followed.

http://freepages.rootsweb.ancestry.c...z/homepage.htm

Thanks
George (theedge2k)

 

[Jerker]

G'day theedge2k,

George, I don't believe you are doing anything wrong at all. Your problem lies with the DEM files you have downloaded (or more correctly the source from which you have downloaded them). To be frankly honest, I have never given any credence to the source you have used. primarily because all reports have indicated that their downloads are less than satisfactory. This is because of numerous reasons but the primary one being that they take the fully available DEMS from here...

ftp://e0srp01u.ecs.nasa.gov/srtm/version2/SRTM3/

...and divided them into 1/4 their size (hence the 'display' you are getting). If you go directly to that site and download the appropriate tile (keeping in mind that tiles are labelled for their South West corner and that if the area you require lies, for example, within the area covered by N40W75 (South West corner) to N41W76 (North East corner), then you must download the tile labelled N41W75...

Jerker {}

 

[MrScott2006]

Keep in mind that the steps your looking at are for microdem 7.0. If you downloaded microdem recently you most likley downloaded 10.0.

What time of files did you download...(extensions)?

 

[theedge2k]

The version i have is "Build 2008.12.30.1" that's the version i have now.

Hey Jerker: how do i find the coordinates?

 

[Jerker]

G'day theedge2k,

George, you shouldn't HAVE to 'find' the co-ordinates, they should already be known to you! Say, the main town of your route is Matlock (in England), for example. Matlock (the last time I looked), is located at N53 W1, that is 53 degrees North 1 degree W, which means that to obtain a DEM tile that will include the area around Matlock (which, incidentally from NASA occupies a whole 1 degree x 1 degree area), you need to download the tile labelled N54W1...

Jerker {}

 

[theedge2k]

Hello Jerker: The Name of one town is Cobre, Nv. I did not see any place to put that name and when i went under north america all i saw were N10W110.hgt.zip to N60W174.hgt.zip Is this what your talking about? I think i figured it out, I downloaded *.hgt file. Do you know what that is or where it goes? I tried to open the file in Microdem and it did what all the dems have done opened very small box in the windows in the upper left. Cobre, Nv is located at latitude 41.112 and longitude -114.401. The elevation is 5,922 feet. So i downloaded N41W114.hgt.zip

 

[theedge2k]

Hey Jerker, did you see what I posted? Microdem has me screwed up. Can you shed some more light on this please.

George

 

[Jerker]

G'day theedge2k,

Firstly, my apologies for the 'slack' response (real life occasionally gets in the way of Trainz and I have been 'absent' from the forum in recent days). However, if the location you need is 41.112 by -114.401, then you actually need to get DEM tile 42N114W. All these files from the N. A. S. A. S. R. T. M. site are *.zip type files which MicroDEM will automatically open and unzip for you but if you feel so inclined, you may unzip them beforehand yourself to their native *.hgt format and then 'import' that into MicroDEM. Having said that, it has been quite some time since I have used MicroDEM and I cannot really say why the tile should not be filling the entire area of the available space when it is loaded into the program (when I last used it, my version of MicroDEM did precisely that), without actually seeing what you are doing or how you have MicroDEM set up in your installation.

Jerker {}

 

[markbin]

hi ,
try using a lower screen resolution ( 1024x768 ) ; as the window of the loaded hgt cant be resized , you will get a larger picture.

 

[RPearson]

You can also try setting default map size. Select Options -> Maps -> Default size.

Bob Pearson

 

[theedge2k]

Rpearson: can you shed some light on what you mean. Is there an easier way to convert maps? Woo Hoo all right it worked i feel that i will be triumphant now woowee. Ok guys what is the next step?

 

[theedge2k]

Well i have gotten to the point where I am supposed to open the tiger lines by using Microdem\overlay\alltiger. but that is not an option in microdem if some one has a way to fix this i would love to hear it please.

 

[RPearson]

Somebody else had this problem and when I looked in the version of MD that I had which was version 10.0 I found the alltiger option but it was build 2007.1.26.1. Last weekend I dl'd the latest copy which is version 10.0 build 2009.4.17.4 and it doesn't.

Now you have to select overlay -> vector outlines. In the dialog box that comes up make sure "files of type" selection is TIGER files. You may have to browse to the directory you put them in if it isn't the TIGER directory under mapdata. MD will unzip files if necessary so no need to do that yourself.

Bob Pearson

 

[theedge2k]

I will try that, I know i placed the zip file in a sub folder called tiger.