[Xastir] Tiger 2007 shapefile issue...a beaut

2008-07-13 Thread Richard Polivka, N6NKO
I admit that one point does not make a trend but what I found was 
eyeopening.


I wanted just Fond du Lac county in Wisconsin to use as a base map for 
mapping project that I am working on ( a Boy Scout campground). I pulled 
in my files into QGIS and then brought in  fe_2007_55039_edges. I did 
not get Fond du Lac County but a huge overview of north Illinois, 
Indiana and SE Michigan. OUCH!!!


I even went and downloaded a virgin fileset and got the same results 
(see picture).


55039.png
This is not good. I plan on sending on a comment to the Census Bureau.

So, let the user beware - YMMV.

73 from 807,

Richard, N6NKO

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Re: [Xastir] Tiger 2007 shapefile issue...a beaut

2008-07-13 Thread Gerry Creager

Richard Polivka, N6NKO wrote:
I admit that one point does not make a trend but what I found was 
eyeopening.


I wanted just Fond du Lac county in Wisconsin to use as a base map for 
mapping project that I am working on ( a Boy Scout campground). I pulled 
in my files into QGIS and then brought in  fe_2007_55039_edges. I did 
not get Fond du Lac County but a huge overview of north Illinois, 
Indiana and SE Michigan. OUCH!!!


I even went and downloaded a virgin fileset and got the same results 
(see picture).


55039.png
This is not good. I plan on sending on a comment to the Census Bureau.

So, let the user beware - YMMV.


Unfortunately, this warning has always been necessary with TIGER files. 
 They're not the best GIS data source.  They're just available and free.

--
Gerry Creager -- [EMAIL PROTECTED]
Texas Mesonet -- AATLT, Texas AM University
Cell: 979.229.5301 Office: 979.458.4020 FAX: 979.862.3983
Office: 1700 Research Parkway Ste 160, TAMU, College Station, TX 77843
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Re: [Xastir] Tiger 2007 shapefile issue...a beaut

2008-07-13 Thread Gerry Creager

Richard Polivka, N6NKO wrote:

Gerry,

Yes, the coffee has kicked in and I had egg-on-face for breakfast. The 
map in QGIS looks just like the same as the aforementioned area when at 
full extent view. Zoomed in, it works.


The egg comment has to do with a Census screwup... It's Census, it's 
gonna happen.  Their view of GIS has been interesting for some time.


I am glad you got it to work!

Error budget - Well, I am within 5 ft on backtracked trails. Can't 
complain for working under a tree canopy.


1.8m isn't bad, at all!  Now: Imagine what happens when your typical 
error is 2-3 meters, and a picnic table is smaller in at least one 
dimension is smaller than the error budget.  The geometry is, well, 
interesting, and usually looks more like a bow-tie than a rectangle. 
Getting several points to define the radius of a trash can gets even 
more entertaining.


I had the GPS unit on top of a 7 ft PVC pipe talking to my smartphone 
over bluetooth. I just ran out of time to cover the whole place but the 
proof of concept pans out.


When I go do this stuff, I use a 2m range pole.  a fixed height 
fiberglas and metal deal designed to poke holes in shoes and give one a 
good feel that their antenna is exactly this high above the point in 
question.  We also have a bulls-eye level on it to allow us to get it 
spot-on above the point in question.


Your rig sounds easier to work with.

gerry


Now its off to other work tasks.

73 from 807,

Richard, N6NKO


Gerry Creager wrote:

Richard Polivka, N6NKO wrote:

Gerry,

Good morning!

I realize that wholeheartedly, but to have this big of a 
screwupoh, wait, this is the Federal Government


Aha!  Your coffee kicked in?  What hardware are you using for your 
campground survey?  I can tell you stories about those from several 
years ago, when folks were trying to resolve objects (e.g., a picnic 
table) that was smaller than their uncorrected L1 error budget...


gerry


Gerry Creager wrote:

Richard Polivka, N6NKO wrote:
I admit that one point does not make a trend but what I found was 
eyeopening.


I wanted just Fond du Lac county in Wisconsin to use as a base map 
for mapping project that I am working on ( a Boy Scout campground). 
I pulled in my files into QGIS and then brought in  
fe_2007_55039_edges. I did not get Fond du Lac County but a huge 
overview of north Illinois, Indiana and SE Michigan. OUCH!!!


I even went and downloaded a virgin fileset and got the same 
results (see picture).


55039.png
This is not good. I plan on sending on a comment to the Census Bureau.

So, let the user beware - YMMV.


Unfortunately, this warning has always been necessary with TIGER 
files.  They're not the best GIS data source.  They're just 
available and free.

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--
Gerry Creager -- [EMAIL PROTECTED]
Texas Mesonet -- AATLT, Texas AM University
Cell: 979.229.5301 Office: 979.458.4020 FAX: 979.862.3983
Office: 1700 Research Parkway Ste 160, TAMU, College Station, TX 77843
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Re: [Xastir] Tiger 2007 shapefile issue...a beaut

2008-07-13 Thread Gerry Creager
Now decorrelate the GPGLL sentences from the 4-hr test by decimating to 
30- or 60-second intervals.  Decorrelation really does help.


Average, then use a least-squares method to determine residual error.

I don't use choke-rings or ground planes when doing kinematic work.  We 
do make sure the antenna is aligned to N when we do it, though, as 
pattern will affect results.


Finnegan's Finagiling Factor (also called bias in literature) has 
saved my butt a bunch of times in the field.  I do a version of that in 
post-processing, too, but the whole procedure is best described in a 
journal article or over a beer.  Or both.


Richard Polivka, N6NKO wrote:

Alright, here are the details of the equipment:

- About 7' of 1.25 PVC pipe with a hole through it for a rubber band to 
hold onto GPS unit

- US GlobalSat BT-359 Bluetooth GPS receiver - chipset: SiRF STAR-III/LP
- Cingular 8525 smartphone
- Turbo GPS software Ver 2.00 alpha 8

Did testing in NMEA mode. SiRF mode has the longitude really messed up. 
I think I will hit up a couple of BM's and see how bad the data is. 
Maybe it may be recoverable by applying Finnegan's Fudge Factor.


Trying to resolve a garbage can using just L1 and a consumer grade GPS 
will just give you garbage when you have only ddmm. to use. I went 
in knowing what the maximum resolution is: one count latitude = 0. 
meters; one count longitude = 0.1630 meters. I was willing to spot the 
rig +/- five counts moving so I would say that I made my self-imposed 
limit. I thought that it would be worse.


Using a 2m range pole with a surgical sharp pick at the end will do your 
feet some damage. You probably have a outrageously overpriced choke ring 
antenna on top and that in itself is a real headknocker in its own 
right. I did a test with this setup here at home one day over four 
hours. I pulled out the NMEA $GPGLL sentences that were at PDOP= 0.6 and 
mapped them out. The resulting x-y graph presented an almost circular 
pattern of a diameter of 8 counts. Averaging the readings put the 
average right in the middle of the chart. I am quite happy with this 
mashup. Not professional grade but it will do the jobs that I need it to 
do.


Have a good week. Now to pull up a property survey to figure out an 
issue for someone.


Best Regards,

Richard, N6NKO



Gerry Creager wrote:

Richard Polivka, N6NKO wrote:

Gerry,

Yes, the coffee has kicked in and I had egg-on-face for breakfast. 
The map in QGIS looks just like the same as the aforementioned area 
when at full extent view. Zoomed in, it works.


The egg comment has to do with a Census screwup... It's Census, it's 
gonna happen.  Their view of GIS has been interesting for some time.


I am glad you got it to work!

Error budget - Well, I am within 5 ft on backtracked trails. Can't 
complain for working under a tree canopy.


1.8m isn't bad, at all!  Now: Imagine what happens when your typical 
error is 2-3 meters, and a picnic table is smaller in at least one 
dimension is smaller than the error budget.  The geometry is, well, 
interesting, and usually looks more like a bow-tie than a rectangle. 
Getting several points to define the radius of a trash can gets even 
more entertaining.


I had the GPS unit on top of a 7 ft PVC pipe talking to my smartphone 
over bluetooth. I just ran out of time to cover the whole place but 
the proof of concept pans out.


When I go do this stuff, I use a 2m range pole.  a fixed height 
fiberglas and metal deal designed to poke holes in shoes and give one 
a good feel that their antenna is exactly this high above the point in 
question.  We also have a bulls-eye level on it to allow us to get it 
spot-on above the point in question.


Your rig sounds easier to work with.

gerry


Now its off to other work tasks.

73 from 807,

Richard, N6NKO


Gerry Creager wrote:

Richard Polivka, N6NKO wrote:

Gerry,

Good morning!

I realize that wholeheartedly, but to have this big of a 
screwupoh, wait, this is the Federal Government


Aha!  Your coffee kicked in?  What hardware are you using for your 
campground survey?  I can tell you stories about those from several 
years ago, when folks were trying to resolve objects (e.g., a picnic 
table) that was smaller than their uncorrected L1 error budget...


gerry


Gerry Creager wrote:

Richard Polivka, N6NKO wrote:
I admit that one point does not make a trend but what I found was 
eyeopening.


I wanted just Fond du Lac county in Wisconsin to use as a base 
map for mapping project that I am working on ( a Boy Scout 
campground). I pulled in my files into QGIS and then brought in  
fe_2007_55039_edges. I did not get Fond du Lac County but a 
huge overview of north Illinois, Indiana and SE Michigan. OUCH!!!


I even went and downloaded a virgin fileset and got the same 
results (see picture).


55039.png
This is not good. I plan on sending on a comment to the Census 
Bureau.


So, let the user beware - YMMV.


Unfortunately, this warning has always 

Re: [Xastir] Changing text color on stations

2008-07-13 Thread Ronny Julian
Just getting back.  My Firefox install dies for some reason everytime I try to 
access Yahoo mail.  I have to use the Wifes Windoze machine here until I figure 
that one out.  Thanks for the replies!




- Original Message 
From: Lee Bengston [EMAIL PROTECTED]
To: Xastir - APRS client software discussion xastir@xastir.org
Sent: Thursday, July 10, 2008 2:02:46 PM
Subject: Re: [Xastir] Changing text color on stations

Thanks!  At least I know my reply didn't go into the bit bucket.


On Wed, Jul 9, 2008 at 10:55 PM, Matt Werner [EMAIL PROTECTED] wrote:
 You had a reply a few hours after the original post:

 On Sun, Jul 6, 2008 at 10:11 PM, Lee Bengston [EMAIL PROTECTED] wrote:
 On Sun, Jul 6, 2008 at 5:09 PM, Ronny Julian [EMAIL PROTECTED] wrote:
 I got Xastir up and running with Tigermaps.  One thing I'm not seeing is 
 how to change the text color of station lables to something more readable.  
 Is it also posible to change the Font size just a bit larger?  Thanks!
 Ronny K4RJJ

 For more readable station text, click (in the menu) Map / Configure /
 Station Text Style / Text on Black

 If you are running a recent version of Xastir from CVS, you can change
 the station font size via File / Configure / Fonts and then edit the
 size of the current station font.

 Regards,
 Lee - K5DAT



 On Wed, Jul 9, 2008 at 10:52 PM, Ronny Julian [EMAIL PROTECTED] wrote:
 Anyone Anyone...

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