tk.ts.f.a.a.d: ??????????

[Guest]

I know this is a long shot at this point but I was trying to render the elevation data for Alaska through Terrascene and got the following error message:tk.ts.f.a.a.d: Expected 1201 profiles for one degree (1:250,000) DEM!I did a thorough search of the Fly! forums (new, old, and very old) but have found no other reports of this particular error. Does anyone have a clue as to what it means and how I might resolve it. I'm only trying to get the elevations to import into Fly!2 as there is very little landcover data for Alaska available. I know the message above is for the 250K DEMs but I don't know what the "1201 profiles" might be.Thanks for any help, even wild guesses.Don

[Guest Colins2]

DonThe USGS DEM files usually come with 1201 columns.It's interesting to use a DEM viewer before importing your data,just to see what the elevations are like.These utilities will display the header and give width x depth.I guess your Alaska DEMs don't have sufficient data for TS2.Colin

[Guest]

Thanks Colin. Looks like that's it. I'd never used a DEM viewer before -- just downloaded the free USGS viewer (a great tool by the way, can be found here: http://mcmcweb.er.usgs.gov/drc/dlgv32pro/) and it showed the USGS data for Alaska having an image width of 601 and height of 1201. By comparison, data I checked at random from the lower 48 states was all 1201 for both height and width.It's funny because at one time, using version one of TS for the original Fly with some shapefile info, I was able to create a globe tile around Anchorage. I wonder if some instruction got left out of the TS update. Also the DEM data for Alaska has to be downloaded manually because TS doesn't look for it in the proper location at USGS. Most of the USGS data is alphabetical except for Alaska which is listed under Alaska instead of under "A". Once I downloaded it and placed each DEM alphabetically under C:Flight SimulatorsTerminal Reality StuffTerraScene2data-filesusgsDEM250 TS then read it just fine but in the render process stops with the 1201 error message. Colin, or Todd if you read this, any chance of a work-around?Don

[Guest Colins2]

Hi Don,The only way that I can think of offhand is to let the Fly Editor import the DEM data for you.This can be done with the 'old-fashioned' style *.txt file with just the DEM section filled in.This is much the same process as for Fly!1.I guess, however, that you were wanting the TS effects for the elevations?I can't see any way to get TS to read the file, maybe Todd can shed some light.Colin

[Guest]

Colin,I'll try playing with the Fly! editor this weekend. Also I was wondering about the VisiDem utility as a possibility. I noticed it can run a batch file but when I tried it to examine one of the DEMs it seems to only be able to read uncompressed data!Also, for anyone interested I found the following explanation on spatial resolution for the 1 degree DEMs on the USGS site:"Spacing of the elevations along and between each profile is 3-arc seconds with 1,201 elevations per profile. The exception is DEM data in Alaska, where the spacing and number of elevations per profile varies depending on the latitudinal location of the DEM. Latitudes between 50 and 70 degrees North have spacings at 6 arc seconds with 601 elevations per profile and latitudes greater than 70 degrees North have spacings at 9 arc seconds with 401 elevations per profile."Don

[Guest]

Just to follow-up on this for those who might be interested, I did try both VisiDem and GTOPO30 this weekend. Both worked very well, VisiDem with the uncompressed DEM data for Alaska and GTOPO30 with the dummed down data set (as I understand it GTOPO30 data for Alaska is based on a sample of the data points in the USGS DEM data. Both processes looked pretty good. I created a large array of about 50 globe tiles with each tool and then used the Fly! II editor to import the RAS file. When using the default resolution settings the resulting file size imported was about 60 MB for DEM data for about 50 globe tiles and about 30 MB for GTOPO30. I also experimented with non-default resolutions and 8x8 instead of 4x4. This doubled the file size and generated a huge number of polygons.Here are two shots, the first outside of Anchorage and the second over the top of Mt. McKinley using the USGS DEM data at 4x4 and 500 feet, i.e. default.Don

[Guest]

Hi Don,It looks like you found the answer, TS2 does not support the Alaska DEM's because they are laid out differently than the rest of the 1-degree DEMs. I just never got a chance to necessary coding, but as you found out, you can import the elevation data using other tools.Todd

[Guest]

Don,I am interested in using TS/TM to generate scenery for SE Alaska, and had the same question about the Alaska DEM data and how to use it. Can you explain how you got VisiDem to read the DEM data for Alaska and used the Fly!2 editor to import the RAS file? I'm very new to this process and have limited experience with TS, but would like to give it a try.Thanks!Jeff H

[Guest]

Hi Jeff,As it happens, I hope to upload detailed elevations for Southeast Alaska some time in the next week or two, dependent on my work schedule. When I have a little more time I'll try to write up a step by step for generating elevations for Alaska. For now, when using VisiDem, remember that VisiDem only seems to work with uncompressed DEM data, the opposite of Terrascene which uses only compressed DEMS. Both sets are available at the EROS site. The other problem you will have in using Terrascene is that there is no landcover data, except for one small exception, available for Alaska for Terrascene to use. The only thing I use Terrascene for is to identify which DEMS need to be downloaded, i.e., run Terrascene for the area of Alaska you want to create. Terrascene will run but end with an error message as indicated above about the data basically being in the wrong format but the log will give you a list of those files you need. You can then go to the EROS site and download those files manually (making sure you download the uncompressed ones). Then open those files in VisiDem and it can create the ras file you need for importing into Fly! You can then use PodCreator available at AVSIM to pod of the elevation data for importing into Fly!There is a howto on importing elevation data with the Fly! editor that someone uploaded awhile back -- sorry I don't recall the name at the moment but I think if you search the TRI Fly! uploads and search for "elevation" you should see it. One other thing -- VisiDem will only create a ras file for rectangular areas that are complete (no empty cells). This works fine but on long angular shorelines your left with a series of lopsided rectangles stacked on top of each other (i.e., Aleutians, Southeast Alaska) that need to be merged into one file. That's where I am now with Southeast Alaska. Other than that it's pretty much step by step.Good luck!Don

[Guest]

Don,Thanks very much for the speedy reply. This information is very helpful. I look forward to seeing the SE Alaska elevations, when you get the chance to upload them. I appreciate very much the hard work you've already put into this!Cheers,Jeff