[offtopic] acquiring Alaska data

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[offtopic] acquiring Alaska data

Matt Wilkie
Hi All,

I've tried half a dozen times to figure out how to use the USGS
EarthExplorer and related sites to acquire large chunks of data along
the Alaska side of the Yukon/Alaska border. I just don't get it, I'm
just too stupid to understand how it is supposed to work I guess.

At the moment I'm particularly interested in 30m elevation models and
vector hydrography of similar scale (works out 1:63,660 I believe) for
the area bounded by 59N,140W 71N,150W.

I eventually discovered a PDF (which now I can't relocate, thank
$diety I printed it) which mentions pre-packaged cdroms for the
seamless National Elevation Dataset. This sounds perfect, except the
document doesn't explain how to get them. There is a 1-800 number, but
it doesn't seem to work from Canada. I called the next number down,
for EROS Data Centre and was eventually bounced around to someone's
voicemail, as yet unanswered (though truthfully I haven't waited
long).

For the NED, I'd like cd #'s 91 through 95, and whatever the
equivalent cd's are for base topo information. Preferred delivery is
ftp/http (sorry can't do bittorrent) but if they are only available on
physical media I'll be happy with that too. Just tell me where to send
a few dollars to expedite the process.

thank you for your time, and I hope insight!

-matt
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Re: [offtopic] acquiring Alaska data

Matt Wilkie
Hi Joe, thanks for your thoughts.

>         Generally I use the USGS Seamless data server to grab data and have found it
> works fine....
>         http://seamless.usgs.gov/

doesn't work for me. Half the time the map area is blank, other times
zoom in/out causes various layers and scales to be showing at the same
time (e.g. hawaii and alaska are on top each other). I've selected
area to dnld by drawing with the green box, and by entering
coordinates. The server appears happy to accept my request, the little
globe in the corner spinning happily for minutes at a time, but no
apparent result. The results between Firefox 2 and Internet Explorer 6
are different in detail but not in result. I'm in awe of the data the
USGS has put together and made available, but the delivery system has
me stumped. I miss the old days when one could just troll through a
big mess of ftp directories and grab what you needed. :)

>         I have a 90m DEM for all of Alaska generated from INSAR that i also use, this
> came from ASF.
>         http://www.asf.alaska.edu

ahh, I hadn't discovered them yet, thanks!

>         I think you may find that the issue  is that the NASA SRTM DEM (the "global"
> shuttle interferometric mapping mission,) doesnt actually have data above about
> 60N... this means most people i know use SAR derived data instead.

yeah, we know about that alright. Maybe it's better for us though if
everything north of 60 keeps getting ignored. :)

>         if you can find what you want from the usgs seamless server.... but the files
> are too big (theres a 250mb limit),

oh, maybe that's what's going wrong. I'm requesting too big of an area.

thanks again,

--
-matt
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Re: [offtopic] acquiring Alaska data

joh3@lithophile.com
Yeah i just tried on the seamless server...

it tells me

You have requested an estimated 7,920 MB of data.
The maximum currently allowed is 1,500 MB.

.... so yeah the area is too big.....

to get this to work.... (i often have the same problems as you)

on the toolbar for the seamless server...

look in the downloads ( shown in red) section... the X,Y option then type in the
range...

after typing in the range it takes you to the results page.... this is empty...

so go to "modify data request", and choose the alaska data set from the bottom.

....

when i do this, I can get data in 1 degree E W increments that way for your
entire area.... their 150mb each.


if want too you can go the asf route....
at ASF you might try contacting Rudi Gens.... he may be able to help you, with a
90m dem if that will do for your application. he may have better than that too
but that is all i know of

his email is
rgens <at sign here> asf.alaska.edu

Hope this helps

Joe


Matt Wilkie wrote:

> Hi Joe, thanks for your thoughts.
>
>>         Generally I use the USGS Seamless data server to grab data and
>> have found it
>> works fine....
>>         http://seamless.usgs.gov/
>
> doesn't work for me. Half the time the map area is blank, other times
> zoom in/out causes various layers and scales to be showing at the same
> time (e.g. hawaii and alaska are on top each other). I've selected
> area to dnld by drawing with the green box, and by entering
> coordinates. The server appears happy to accept my request, the little
> globe in the corner spinning happily for minutes at a time, but no
> apparent result. The results between Firefox 2 and Internet Explorer 6
> are different in detail but not in result. I'm in awe of the data the
> USGS has put together and made available, but the delivery system has
> me stumped. I miss the old days when one could just troll through a
> big mess of ftp directories and grab what you needed. :)
>
>>         I have a 90m DEM for all of Alaska generated from INSAR that i
>> also use, this
>> came from ASF.
>>         http://www.asf.alaska.edu
>
> ahh, I hadn't discovered them yet, thanks!
>
>>         I think you may find that the issue  is that the NASA SRTM DEM
>> (the "global"
>> shuttle interferometric mapping mission,) doesnt actually have data
>> above about
>> 60N... this means most people i know use SAR derived data instead.
>
> yeah, we know about that alright. Maybe it's better for us though if
> everything north of 60 keeps getting ignored. :)
>
>>         if you can find what you want from the usgs seamless
>> server.... but the files
>> are too big (theres a 250mb limit),
>
> oh, maybe that's what's going wrong. I'm requesting too big of an area.
>
> thanks again,
>


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Re: [offtopic] acquiring Alaska data

Matt Wilkie
AHA, thanks to your help, I've figured out one can bypass the map
viewer altogether and put the coords on the URL like so:

http://extract.cr.usgs.gov/Website/distreq/RequestSummary.jsp?AL=71.0,56.0,-140.0,-150.0&PL=NAK01HZ,

"AL=71.0,56.0,-140.0,-150.0" --> region of interest,
Lat-North,Lat-South Long-East,Long-West

"PL=NAK01HZ"  --> data set to choose from, in this case "National
Elevation Dataset Alaska (NED) 2 Arc Second"

Now I just have to figure out what all the other secret codes are.

>  if want too you can go the asf route....
> at ASF you might try contacting Rudi Gens....

I'll do that, thank you very much.

--
-matt
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Re: [offtopic] acquiring Alaska data

joh3@lithophile.com
great!
        Just remember the NED alaska data, is a little "special".... so if you need
absolute accuracy, it may not be up to scratch.

        Cheers
                Joe
Matt Wilkie wrote:

> AHA, thanks to your help, I've figured out one can bypass the map
> viewer altogether and put the coords on the URL like so:
>
> http://extract.cr.usgs.gov/Website/distreq/RequestSummary.jsp?AL=71.0,56.0,-140.0,-150.0&PL=NAK01HZ,
>
>
> "AL=71.0,56.0,-140.0,-150.0" --> region of interest,
> Lat-North,Lat-South Long-East,Long-West
>
> "PL=NAK01HZ"  --> data set to choose from, in this case "National
> Elevation Dataset Alaska (NED) 2 Arc Second"
>
> Now I just have to figure out what all the other secret codes are.
>
>>  if want too you can go the asf route....
>> at ASF you might try contacting Rudi Gens....
>
> I'll do that, thank you very much.
>


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Re: [offtopic] acquiring Alaska data

John C. Tull-2
In reply to this post by Matt Wilkie
Also be sure to modify your request and have the data delivered as  
tar gzipped files (or whatever the alternative to zip is). Especially  
with the NEDs, I find that the directory structure gets all screwed  
up when they are unzipped from standard zip format. This is on a Mac,  
so it may be OS dependent. Just thought I would throw it out there.

John Tull

On Mar 8, 2007, at 4:50 PM, Matt Wilkie wrote:

> AHA, thanks to your help, I've figured out one can bypass the map
> viewer altogether and put the coords on the URL like so:
>
> http://extract.cr.usgs.gov/Website/distreq/RequestSummary.jsp?
> AL=71.0,56.0,-140.0,-150.0&PL=NAK01HZ,
>
> "AL=71.0,56.0,-140.0,-150.0" --> region of interest,
> Lat-North,Lat-South Long-East,Long-West
>
> "PL=NAK01HZ"  --> data set to choose from, in this case "National
> Elevation Dataset Alaska (NED) 2 Arc Second"
>
> Now I just have to figure out what all the other secret codes are.
>
>>  if want too you can go the asf route....
>> at ASF you might try contacting Rudi Gens....
>
> I'll do that, thank you very much.
>
> --
> -matt
> _______________________________________________
> Qgis-user mailing list
> [hidden email]
> http://lists.qgis.org/cgi-bin/mailman/listinfo/qgis-user

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Re: [offtopic] acquiring Alaska data

Matt Wilkie
In reply to this post by Matt Wilkie
On 3/8/07, Matt Wilkie <[hidden email]> wrote:
> AHA, thanks to your help, I've figured out one can bypass the map
> viewer altogether and put the coords on the URL like so:
> http://extract.cr.usgs.gov/Website/distreq/RequestSummary.jsp?AL=71.0,56.0,-140.0,-150.0&PL=NAK01HZ,
>
> "AL=71.0,56.0,-140.0,-150.0" --> region of interest,
> Lat-North,Lat-South Long-East,Long-West
>
> "PL=NAK01HZ"  --> data set to choose from, in this case "National
> Elevation Dataset Alaska (NED) 2 Arc Second"

building on this, I've determined it's also possible to construct a
URL to go straight to the extraction stage and use arbitrary area of
interest extents. Looking at the html generated by the previous
request, we can change the POST form to a GET request, which looks
like this (needs to be all on one line to work):

http://extract.cr.usgs.gov/diststatus/servlet/gov.usgs.edc.RequestStatus
?siz=87
&key=NAK
&ras=1
&rsp=1
&pfm=ArcGRID
&imsurl=-1
&ms=-1
&att=-1
&lay=-1
&fid=-1
&dlpre=
&wmd=1
&mur=http%3A%2F%2Fextract.cr.usgs.gov%2Fdistmeta%2Fservlet%2Fgov.usgs.edc.MetaBuilder
&mcd=NED
&mdf=HTML
&arc=ZIP
&sde=ned.ak_ned
&msd=NED.CONUS_NED_METADATA
&zun=METERS
&prj=0
&csx=5.55555555556E-4
&csy=5.55555555556E-4
&bnd=
&bndnm=
&RC=d9b131a2a5e3589013aaddb1d5f567585db594
&lft=-148.33333333333334
&rgt=-146.66666666666669
&top=63.0
&bot=59.0

for my purposes, it's these last four which are useful. Change them like so

&lft=-143&rgt=-140&top=71.0&bot=59.0

and then each in turn:

&lft=-147&rgt=-143&top=71.0&bot=59.0
&lft=-150&rgt=-147&top=71.0&bot=59.0

and I have my whole area of interest in three simple requests, plus
there is no need go through the bother of mosaicking a bunch of little
tiles together. It does take the server about 15 or 20 minutes to
process each request though. I didn't attempt to find the maximum
area, as my main goal is to get the data, not find the limits of their
server and crash it. ;-)

If you use this technique, please be gentle. It's not in our interests
to force them to take protective measures and close this avenue.
Thanks.

--
-matt
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Re: [offtopic] acquiring Alaska data

Matt Wilkie
In reply to this post by John C. Tull-2
On 3/9/07, John C. Tull <[hidden email]> wrote:
> Also be sure to modify your request and have the data delivered as
> tar gzipped files (or whatever the alternative to zip is). Especially
> with the NEDs, I find that the directory structure gets all screwed
> up when they are unzipped from standard zip format. This is on a Mac,
> so it may be OS dependent. Just thought I would throw it out there.

I didn't read your warning until I'd already downloaded everything.
Happily I can report that on Windows both command line unzip from
cygwin and with 7zip gui the archives extract properly.

Having has many problems in the past with WinZip and the built-in zip
support with Windows XP Explorer I didn't even try them.

cheers,

--
-matt
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Re: [offtopic] acquiring Alaska data

Matt Wilkie
In reply to this post by Matt Wilkie
> I eventually discovered a PDF (which now I can't relocate, thank
> $diety I printed it) which mentions pre-packaged cdroms for the
> seamless National Elevation Dataset. This sounds perfect, except the
> document doesn't explain how to get them. There is a 1-800 number, but
> it doesn't seem to work from Canada. I called the next number down,
> for EROS Data Centre and was eventually bounced around to someone's
> voicemail, as yet unanswered (though truthfully I haven't waited
> long).

I never did receive a response to my voicemail, but one of the emails
did get answered:

"You can order the entire U.S. in 30 meter resolution in either
ArcGrid or GridFloat format. The data will be provided on a 250 GB
external drive at a total price of $1005.00. This includes shipping
and handling. This will cover the Conterminous U.S., Alaska (at 60
meter res), Hawaii, and the territorial islands. We no longer provide
this on CD or DVD media."

An incredibly good price in my opinion.

The contact address is [hidden email]

Customer Service/Webmapping

Data and Applications Support Department
Science Applications International Corporation (SAIC) at
U.S. Geological Survey - EROS
(Earth Resources Observation and Science)
47914 252nd Street
Sioux Falls, SD 57198-0001

Phone: 1-800-252-4547
Fax: (605)-594-6589


cheers,

--
-matt
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