>DATE: September 04, 2014
RINEX FILE: 35__246o.14o TIME: 20:02:22 UTC
SOFTWARE: page5 1209.04 master91.pl 022814 START: 2014/09/03 14:39:00
EPHEMERIS: igr18083.eph [rapid] STOP: 2014/09/03 18:20:00
NAV FILE: brdc2460.14n OBS USED: 10721 / 10985 : 98%
ANT NAME: TRMR8_GNSS NONE # FIXED AMB: 44 / 49 : 90%
ARP HEIGHT: 1.765 OVERALL RMS: 0.017(m)
REF FRAME: NAD_83(2011)(EPOCH:2010.0000) IGS08 (EPOCH:2014.6731)
X: -1329077.977(m) 0.008(m) -1329078.803(m) 0.008(m)
Y: -4788732.703(m) 0.024(m) -4788731.378(m) 0.024(m)
Z: 3988524.784(m) 0.027(m) 3988524.679(m) 0.027(m)
LAT: 38 56 13.46393 0.007(m) 38 56 13.48279 0.007(m)
E LON: 254 29 18.21112 0.002(m) 254 29 18.16338 0.002(m)
W LON: 105 30 41.78888 0.002(m) 105 30 41.83662 0.002(m)
EL HGT: 2608.189(m) 0.034(m) 2607.302(m) 0.034(m)
ORTHO HGT: 2622.096(m) 0.063(m) [NAVD88 (Computed using GEOID12A)]
UTM COORDINATES STATE PLANE COORDINATES
UTM (Zone 13) SPC (0502 CO C)
Northing (Y) [meters] 4309917.994 427323.497
Easting (X) [meters] 455659.626 913395.438
Convergence [degrees] -0.32153373 -0.00732106
Point Scale 0.99962421 0.99993998
Combined Factor 0.99921531 0.99953095
US NATIONAL GRID DESIGNATOR: 13SDD5565909917(NAD 83)
BASE STATIONS USED
PID DESIGNATION LATITUDE LONGITUDE DISTANCE(m)
AI7401 AMC2 ALTERNATE MASTER CORS ARP N384811.226 W1043128.496 86972.3
DG7426 P037 FREEMONTAPCO2004 CORS ARP N382518.293 W1050616.819 67307.5
DG7429 P041 MARSHALL FIELD CORS ARP N395658.150 W1051139.316 115715.2
NEAREST NGS PUBLISHED CONTROL POINT
JK1269 RIMROCK N385412.996 W1052708.651 6337.9
This was just an exercise, I will be using local coordinates for the project provided by the client. Is the ORTHO HGT supposed to be the elevation [NAVD88]? It misses the clients datum by 0.37 feet. This is the first OPUS report I have ever looked at. Do you see any alarming information in it?
> >DATE: September 04, 2014
> RINEX FILE: 35__246o.14o TIME: 20:02:22 UTC
>
>
> SOFTWARE: page5 1209.04 master91.pl 022814 START: 2014/09/03 14:39:00
> EPHEMERIS: igr18083.eph [rapid] STOP: 2014/09/03 18:20:00
> NAV FILE: brdc2460.14n OBS USED: 10721 / 10985 : 98%
> ANT NAME: TRMR8_GNSS NONE # FIXED AMB: 44 / 49 : 90%
> ARP HEIGHT: 1.765 OVERALL RMS: 0.017(m)
>
>
> REF FRAME: NAD_83(2011)(EPOCH:2010.0000) IGS08 (EPOCH:2014.6731)
>
> X: -1329077.977(m) 0.008(m) -1329078.803(m) 0.008(m)
> Y: -4788732.703(m) 0.024(m) -4788731.378(m) 0.024(m)
> Z: 3988524.784(m) 0.027(m) 3988524.679(m) 0.027(m)
>
> LAT: 38 56 13.46393 0.007(m) 38 56 13.48279 0.007(m)
> E LON: 254 29 18.21112 0.002(m) 254 29 18.16338 0.002(m)
> W LON: 105 30 41.78888 0.002(m) 105 30 41.83662 0.002(m)
> EL HGT: 2608.189(m) 0.034(m) 2607.302(m) 0.034(m)
> ORTHO HGT: 2622.096(m) 0.063(m) [NAVD88 (Computed using GEOID12A)]
>
> UTM COORDINATES STATE PLANE COORDINATES
> UTM (Zone 13) SPC (0502 CO C)
> Northing (Y) [meters] 4309917.994 427323.497
> Easting (X) [meters] 455659.626 913395.438
> Convergence [degrees] -0.32153373 -0.00732106
> Point Scale 0.99962421 0.99993998
> Combined Factor 0.99921531 0.99953095
>
> US NATIONAL GRID DESIGNATOR: 13SDD5565909917(NAD 83)
>
>
> BASE STATIONS USED
> PID DESIGNATION LATITUDE LONGITUDE DISTANCE(m)
> AI7401 AMC2 ALTERNATE MASTER CORS ARP N384811.226 W1043128.496 86972.3
> DG7426 P037 FREEMONTAPCO2004 CORS ARP N382518.293 W1050616.819 67307.5
> DG7429 P041 MARSHALL FIELD CORS ARP N395658.150 W1051139.316 115715.2
>
> NEAREST NGS PUBLISHED CONTROL POINT
> JK1269 RIMROCK N385412.996 W1052708.651 6337.9
>
> This was just an exercise, I will be using local coordinates for the project provided by the client. Is the ORTHO HGT supposed to be the elevation [NAVD88]? It misses the clients datum by 0.37 feet. This is the first OPUS report I have ever looked at. Do you see any alarming information in it?
Yes, the Ortho. Height is the elevation you are looking for. Remember that the ortho height is based on a model, so if you have any local NGS monuments that have been differentially leveled across, then I certainly would hold the leveled elevation. All of the statistics seem excellent. No issues that I can see.
Kinda what Glenn said. Reading all that chinese gobbldey kook is very confusing. Even if we are smart.
I've used OPUS lots, and just attended the newfangled OPUS Projects seminar put on by NGS. A day and a half and well worth the time and limited expenses. Pretty powerful tool to keep in mind if you have the time for long occupations, then just submit back to NGS and it's better than magic. Pretty sure you can hang your hat on it too, since it's "published".
I've mostly used OPUS for remote elevations where there are no bench marks for miles. Usually I'll set up on two points and just split the difference, which is generally within a couple tenths. Works for me.
vern,
Some of your elevation difference can be attributed to the ARP of the antenna. It can be different than where your measuring your H.I. NGS explains it on their website.
Pablo
I accounted for the difference between the bottom of the receiver and the bumper. I'll check if I went the wrong direction on that tomorrow. It is very nearly half the difference.
> .... It misses the clients datum by 0.37 feet. This is the first OPUS report I have ever looked at. Do you see any alarming information in it?
Your OPUS looks like a good one. As far as the 0.37 goes, some of it is OPUS, much of it is probably in the client's source. I suggest running a second session for some indication of how much is OPUS, if you care.
orbit used = precise or rapid
> 90% observations used
> 50% ambiguities fixed
correct antenna and antenna height
Static: overall RMS < 3 cm, peak to peak errors < 5 cm.
Rapid Static: No warning messages.
Quality indicators that are suspiciously low
Normalized RMS that is suspiciously high.
Coordinate standard deviations that are suspiciously high.
Wayne,
Did you attend the OPUS Projects workshop in Tempe? They had two seats left, and I hesitated. When I got ready to hit the gas, it was full.
Dave
Vern,
In addition to Mark's suggestions, here's from the X-90 manual:
"Here are some general rules to help judge the quality of a solution:
The orbit [precise] should be precise or rapid (not-ultra rapid.)
> 90% observations used or > 80% # Fixed Ambiguities
> 50% Fixed Ambiguities or > 95% observations used
Overall RMS < 0.030(m)
Lat / Lon RMS < 0.030(m)
If you collect data under canopy or in an area where there are buildings or trees that obstruct the view above 10° elevation, the number of observations used will be lower.
Make sure you use the left-hand column (NAD_83) results, not the right-hand column (IGS08.)
Be careful with heights. Both ellipsoid and orthometric heights are listed. The orthometric height is NAVD88 GPS derived and typically is the elevation you need.
The RMS error estimate for the orthometric height includes an error estimate for the GEOID in addition to the RMS value for the ellipsoid height.
The state plane coordinates are listed at the bottom in the right-hand column. They are in Meters. If you need Feet, you can convert them, however be careful to convert to International Feet or U.S. Survey Feet as required by your State and application:
US Survey Feet = Meters * (3937/1200)
International Feet = Meters / 0.3048
The misapplication of Ft/M scale factor can result in a 30 foot coordinate blunder! If you request an ‘Extended Format’ OPUS results, the state plane coordinates are computed and returned at the bottom of the report.
If your survey is at a significant elevation (> 100 feet) you may need to apply the Combined Factor (listed on the OPUS report for both UTM and State Plane Coordinates) to inversed distances"
Dave
David I went to the one in Vegas that was sponsored by NALS S Chapter. Free aside from a token $35 to help with lunch. And my room at The D on Fremont St, darn.
I would encourage all surveyors to attend the class
Thank you one and all for the help and links.
I did apply the correction correctly so I do have the 0.37' vertical difference. Next time I go to the job I will collect for another OPUS on a different point with a check back to this one. I really like GPS and RTK!
http://www.ngs.noaa.gov/OPUS/about.jsp
Of course there is good information about OPUS here too. Specifically in the "What to look for in a quality solution" section .