Tonight (04/05/02) should be o.k. for your plans. There was an M6 flair yesterday, but it wasn't aimed at us. The coronal hole that was messing with us most of the week has rotated out of alignment, so the solar wind is down to normal. My totally uneducated redneck astrophysicist SWAG is that you're good to go.

J.D.

At 9:00pm CST

Jimbo

Should be a good one. I looked at mission planning a couple of days ago and it looked to me like the typical orgi session time 0600-1400 utc was as good as the constellation gets right now. I'd doubt yours is a whole lot different than mine so you probably picked the right night.


I'm anxious to hear your results.

Good Luck

J.D.

As Captain Kirk said to Spock... I would rather have you SWAG it, than have a whole roomful of computers any day... I sorta trust your 'in the dirt' logic... (Phil gets my same confidence)..

Good luck Jimbo...

DP

waiting to get the CORS files.

Just scanned thru the graphs of the S/N, SV ELEV, AND CYCLES and nothing looks to bad.

As typical it looks like trash around 15° SV elev and less. probably an 18-20° mask will clean it up nice.

Also looks like with the aforesaid mask I'll have 5 or more SV's for all the session.

We'll see tomorrow.

Jimbo

Ties to 2 Harns
1 JMBO office post
East. 2686221.972 0.010
Nrth. 627294.357 0.009
Elev. 46.389 0.014

Ties to 2 CORS (BEA5 and KJUN)
1 JMBO
East. 2686221.907 0.180
Nrth. 627294.424 0.165
Elev. 45.926 0.144

Ties to 3 CORS (BEA5 and KJUN and WNFL)
1 JMBO
East. 2686221.964 0.179
Nrth. 627294.454 0.172
Elev. 46.171 0.210

Squishing HARNS(2) AND CORS(3) vectors into one project
1 JMBO
East. 2686221.954 0.014
Nrth. 627294.376 0.012
Elev. 46.388 0.164
Notes:

Only adjustments to raw data were to set the start and stop times to match,
and to set the mask angle on all vectors to 18°.


Also note that after diddling with BEA5 VS KJUN and WNFL I think
BEA5 might be -.4'± difference in elev. Yeah, I know this is way outta the box
but it just seems thata way, so I released BEA5 vertical constraint in the
3 CORS and combined CORS/Harn processing.

Jimbo
edit: These are the 95% error levels after the numbers.
Modified By James Webb on 4/8/2002 at 1:05 PM

Jimbo,

Would you let me play with your Locus file. All I want is the file on your tower. I'll pull the CORS data files myself.

Just for fun, when you have the time to send it.

J.D.

Its on the Orgie FTP

jimbo-la/new folder/jimbo.exe

a self extracting zip file.

when I get home I'm gonna rename "New Folder" to 040602

Or I can attach it to an e-mail, jsut under 900k zipped up.

Let me know if ya want it mailed. I just hate sending big files without warning to anybody not on broadband of some sort. Kinda ties up the receiving connection for a while.

Jimbo

Modified By James Webb on 4/8/2002 at 2:52 PM

Just downloaded it. Since my TV managed to O-D from lightning yesterday, I'll have time to piddle with the file for a night or 2.

jd

Beaumont is very unstable vertically. What did you use for the elevation for Beaumont? I noticed that, in the current listing for Beaumont, NGS shows it subsiding at a rate of 1.8 cm per year which would indicate a current NAD 83 ellipsoid height for Beaumont of about -10.63 m, compared to the original 1997 elevation of -10.54 m.

from Stumpwater

JMBO Holding KJUN H & V
WNFL H & v
BEA5 H & V

N 627294.337 0.158 95%
E 2686221.996 0.203 95%
EL 45.612 (Ortho) 0.202 95%

In my case I started with Beaumont (BEA5) at ellipsoid ht -10.631 derived from (-10.54 + (-0.0182m * 5)) as Mr. G suggested. Makes good sense that 1.8cm per year should be accounted for. And Beaumont isn't the only CORS in sinking sand...Houston (HOUS) is at 1.09cm per year too

Here's what I came up with using the same sites, and setting BEA5 as a Horizontal constraint only:

N 627294.336 0.159 95%
E 2686221.991 0.203 95%
El 46.353 (Ortho) 0.292 95%


Something strange with BEA5 in the mix.

I put BEA5 into the soft. at the called 97 elip -10.54. When i run initially totally unconstrained the soft. used BEA5 as the seed. It then calced a misclosure for KJUN and WNFL of about 0.48' vertically.

I then ran constrained to KJUN(H/V) and the soft. called misclosure on BEA5(V) -.41' and ,if I remember correctly, 0.01' on WNFL(V). I then constrained to WNFL(H/V) only and got similar results. Then I constrained KJUN(h/v) AND WNFL(H/V) and again BEA5 appeared to be 0.41' low.

This is how I determined that relative to KJUN and WNFL, BEA5 published elev. was not correct. Guess I shaoulda resad the metadata better !! And it would have been obvious. But I think I used the NGS data sheet, which only refers you to the site data for velocities...my mistake.

Now that I have read it, please explain the following statement quoted from the sheet:

"Transformed from ITRF97 (epoch 1997.0) position in July 2000."

Is this a statementof when the position was actually calced or is this an "updated" position ??

Jimbo

We are in the same ballpark...bet ya cleaned the data files a bit more than I did. Some after 6 am and some I believe around 0230 to 0400, maybe.
:-)

I chopped off time at start - 21:30 4/5//02 and end at 08:30 CST 4/6/02 to allow for my launch and landing !!
;-|

Jimbo
Modified By James Webb on 4/9/2002 at 9:38 AM

Jimbo,

I just made the session run from 0600 to 1400 utc, using only 8 hours of data. There actually may have been better data in the earlier three hours, but not having looked at the mission planning for your site, I just decided to run with the "standard 8 hour" time frame. It would be nice if you had something South though, wouldn't it?

JD

for us guys that believe in strength of figure. For those that don't, wouldn't matter.

Only problem is I don't think they've made a CORS that floats in exactly one spot....yet !! Probably something offshore on a platform somewhere but don't know how to find it or access it.

Haliburton, Schlumberger, Brown and Root, Chance, Pybrum-Odom, somebody has one I'd bet !!

Jimbo

NGS is trying to be helpful but there are lots of numbers floating around that can get to be confusing. The date of July 2000 is the date the coordinates were computed. First of all, to be sure we are talking the same coordinate information from NGS. To look at coordinates here is what I do. After I get to the NGS web site I click on CORS. Then on the left hand side I click on Site Metadata, which opens up options, then I click on Coordinates. Then just under the initial text I click on Most Recent Coordinates. Then scroll down to the site you want on the left hand side and highlight it and highlight Coordinates on the right hand side. Finally just underneath the station list on the right you click on the blue Find Files. This will bring up the latest coordinate information for a site. You would probably get the same information from the main data base but I wnted to be sure we were not talking about apples and oranges.

When I looked today I found that the coordinate files had been updated in March of 2002. Above the NAD 83 coordinates it says L1 Phase Center (Epoch 2002.0) and ARP (Epoch 2002.0) for the two sets of NAD 83 coordinates it gives. This means that the coordinates given are for the NAD 83 position of the CORS station at the beginning of 2002. The statement " Transformed from ITRF97 (or ITRF00.etc) (epoch 1997.0) position in March 2002" means that, from the data they were using in March 2002 to compute the NAD 83 coordinates of the station as of the beginning of 2002, they started with 1997.0 ITRF coordinates, converted them to 1997.0 NAD 83 coordinates using a standard transformation they have developed and then used the NAD 83 velocities given on the data sheet to update the NAD 83 1997.0 coordinates to NAD 83 2002.0 coordinates. In most cases the computed velocities for stations in the US east of the Rockies are very small (of the order of a mm/yr0 and given the short time span of data available for their computation are probably not statistically significant. In these cases whether you used 1997.0 or 2002.0 coordinates for the CORS doesn't really matter. But there are a few stations, such as Beaumont, where signifigant motions are occuring locally. In this case you would want to use the 2002.0 coordinates for the CORS station in your computations.

I'll haveta look when I get to the office in the am, but I'm fairly certain I used the 1997 epoch on BEA5, L1 Phase Center. I believe this is what the User Friendly site sent as the site coordinates in the zipped file, along with the NGS data sheet.

Jimbo