Drunk Driverz and creepy drivers

[JCitron]

This is the link that I use for the DEMs:

http://dds.cr.usgs.gov/srtm/version2_1/SRTM3/

The maps that you'd use are:N42W072.hgt.zip,
N42W073.hgt.zip,
N42W074.hgt.zip

and that covers the area from about Haverhill to Mechanicsville. Thanks for the advice, I was wondering how I should approach importing it into Trainz. I had pretty much decided to do it in sections, though.
Incidentally, I am using the USGS website for the topographic maps and georeferencing them. At this point I have gotten all of the DEMs,the georeferenced maps and routes done from Lowell to Orange. I think I'm going to continue east to Lawrence and incorporate some of the Western route as well. I don't know.... I'm not biting off too much am I?

Thanks for the links. I'll try them and see what happens. I'm still new to the TransDem world myself.

All the way to Lawrence... Biting off too much, I'm sure you are, but Nah! Go for it and see what happens. The worse thing that can happen is your machine might choke though.

The distance from Lawrence to Lunenburg or Ashburnham is about 55 miles up 495 and Route 2. I'm figuring the 10 mile difference from Haverhill as shown by my speedometer. The rail mileage maybe more because the line heads south (west by timetable) to Lowell Junction in Andover first then heads due west to Lowell via Tewksbury, then north along the Merrimack River to North Chelmsford where the wye is for the Stoney Brook line through Westford to Ayer where it connects to the Fitchburg Division at the Willows.

John

 

[geophil]

SRTM is fine for trying out TransDEM. For many places on the planet it is also the only reasonable DEM source. For a proper US route project, however, I would recommend USGS NED DEMs, not SRTM. NED is available from Seamless Server: http://seamless.usgs.gov/website/seamless/viewer.htm.
Make sure to download the DEMs in GeoTIFF format. Here is a very detailed tutorial: http://forum.transdem.de/viewtopic.php?f=6&t=57.

Have a look here for a comparison of DEM resolution:http://forum.transdem.de/viewtopic.php?f=2&t=24. The first image is SRTM 3arc sec, the others are NED.

 

[psferg]

Thanks for the links, geophil. Are the 1/9 DEMs detailed (or sensitive?) enough to pick up the gradient for the rail lines?

John... I suspect my plans will be modified significantly before I get too far! It is great to have the resources to be able to do any of this, though. The reason for such a large area is because that is where I did the bulk of my photography (generally Ayer to E. Deerfield) back in the early '80s.

 

[geophil]

I would be careful with 1/9 arc sec. They really eat up a lot of memory (and are not available for all areas). Compare the last two images here: http://forum.transdem.de/viewtopic.php?f=2&t=24. You can clearly identify the right-of-way for both 1/3 and 1/9 arc sec. I would expect usable DEM-shaped gradients here, too.

 

[JCitron]

SRTM is fine for trying out TransDEM. For many places on the planet it is also the only reasonable DEM source. For a proper US route project, however, I would recommend USGS NED DEMs, not SRTM. NED is available from Seamless Server: http://seamless.usgs.gov/website/seamless/viewer.htm.
Make sure to download the DEMs in GeoTIFF format. Here is a very detailed tutorial: http://forum.transdem.de/viewtopic.php?f=6&t=57.

Have a look here for a comparison of DEM resolution:http://forum.transdem.de/viewtopic.php?f=2&t=24. The first image is SRTM 3arc sec, the others are NED.

Thank you, Roland for your help on this. I've only just started using TransDem now that I have some spare time to focus on the program and documentation.

 

[psferg]

Well, I just imported my first sections into Trainz. The funny thing is, it worked just like it's supposed to. Thanks John and Roland for the advice.