First problem I had a small job thrown at me and had to cover that before doing my main project later than I wanted. The open area next to my survey parcel is the local fire department and they are setting up for a carnival blocking any chance of using a total station.?ÿMy corner search was not as fruitful as desired. I have one control point from previous monitoring wells in their front parking lot and had picked a point in the back from an aerial photo. Thankfully that was not yet occupied by a booth. Open sky but some horizon issues. Late afternoon start so my 4 hour observations ran into the next GPS day. Not as many satellites as I anticipated. Not finding any property corners off the bat, my second point is a found corner for a cell tower easement and it falls under a power line.?ÿ Seven satellites for the duration but two almost never resolve the L2 observations. Besides the 2 OPUS observations I have 3 L only receivers on 5 outlying points. The last two setups had low satellite counts, 5, for a considerable time. To add to that my rod walked off the spike next to sidewalk on one reoccupy tie in point, 0.08' variance in the X direction.
I can live with the lower precision since this is to get my started to lead into overgrown woods and recover property corners. since I have a prior OPUS control point I can even continue if I do not get these two positions today. The carnival is all next week so I can take some time and ponder a bad GPS day.
Paul in PA
Must not be a good week all around.
I didn't do any sessions Thu Aug 30, but wasn't too happy with my Tues/Wed expedition.?ÿ As mentioned in another thread, on Tuesday I found my most desirable bench mark post broken off and severely leaning.?ÿ The next I looked at didn't have decent sky.?ÿ I picked another and got rained on before the forecast time, and seriously rained on at the forecast time - water running over the street curbs as I got back there to pack up.?ÿ That 6.5 hr session came back (rapid orbit) with unacceptable percentages and pk-pk.?ÿ
Wednesday was a nice day, but I ran out of battery before getting enough time on the second session after opting to try for 2x 4-hr instead of a longer one.?ÿ The rapid orbit data for those two sessions disagree by 4 cm elevation.?ÿ Darn.?ÿ Maybe that tree to the south had more effect than I hoped.
A tree near the horizon has little affect on elevation, as the best elevation calculation geometry comes from satellites high in the sky.
If your goal is elevation use OPUS-RS as elevation is best calculated from closer CORS that surround the position and have the best ionospheric model engine. OPUS is set up to give horizontal positions from any CORS even if they are all biased top one side.
Paul in PA
I dunno bout the last couple of days, but here are some REPEAT shots on a control point the last 3 days Matt was there (all units US Ft.).
?ÿ North Ft.?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ P-P?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ East Ft.?ÿ?ÿ?ÿ?ÿ?ÿ P-P?ÿ?ÿ?ÿ?ÿ NAVD88?ÿ?ÿ?ÿ?ÿ ?ÿP-P?ÿ?ÿ?ÿ?ÿ ?ÿTime?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ ?ÿDate
1 191618.401 (0.033) 52204.750 (0.023) 7560.904 (0.066) 9h44m 8/23-24/2018
2 191618.404 (0.033) 52204.748 (0.039) 7560.910 (0.069) 7h01m 8/25-26/2018
3 191618.397 (0.033) 52204.745 (0.030) 7560.986 (0.046) 8h37m 8/28-29-2018
Just got two solutions, first one 4 hr 27 min, 86% of 9067 observations I am very happy with. Second one 3 hr 57 min, I was getting tired, 82% of 6043 observations will suffice as a basis for corner searching. That 82% means a average of 5 satellites for the duration. I imagine two factors contributing to that, directly overhead power lines and a cell tower 60 feet to the North. I will be traversing through GPS points and will most likely take GPS back and locate a published control point on my original site.
Paul in PA
If your goal is elevation use OPUS-RS as elevation is best calculated from closer CORS that surround the position
My goal is good quality solutions to share for GPSonBM (with emphasis on elevation), which requires 4-hour minimum OPUS-S and won't take OPUS-RS.
GPS checks were very tight, although the base was collecting on control points it's doubtful anyone sent a file to OPUS
1 Hour 03 Min. OPUS_RS yesterday, first time I have used it in years (for good reason).
Lat:?ÿ 0.015(m)?ÿ?ÿ?ÿ?ÿ
Lon: 0.006(m)
EL HGT:?ÿ?ÿ?ÿ?ÿ 0.166(m)
?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ BASE STATIONS USED
?ÿPID?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ DESIGNATION?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ LATITUDE?ÿ?ÿ?ÿ LONGITUDE DISTANCE(m)
?ÿDJ8989 P030 KEMMERERLFWY2005 CORS ARP?ÿ?ÿ?ÿ?ÿ?ÿ N414459.315 W1103046.066?ÿ 151061.7
?ÿDP9024 PUC2 CARBON COUNTY UT CORS ARP?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ N393538.100 W1104541.525?ÿ 126133.4
?ÿDQ8876 UTMN MAPLETON UT CORS ARP?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ N400839.699 W1113544.075?ÿ?ÿ 51261.1
?ÿDG9776 P122 CNRSPRNGS_UT2004 CORS ARP?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ ?ÿN413807.289 W1121954.849?ÿ 136827.8
?ÿDG8517 AHID AUBURN HATCHERY CORS ARP?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ N424623.209 W1110349.415?ÿ 244315.6
?ÿDL7734 P100 PARKVALLEYUT2007 CORS ARP?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿN415124.466 W1131739.124?ÿ 208072.1
?ÿDI2242 P009 MARYSVALE_UT2006 CORS ARP?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ?ÿ ?ÿN382847.732 W1121321.725?ÿ 243756.1
?ÿDL7737 P113 KNOLLSWESTUT2006 CORS ARP?ÿ?ÿ?ÿ?ÿ?ÿ N404016.678 W1131640.872?ÿ 153956.8
?ÿDG7432 P057 HILL72____UT2004 CORS ARP?ÿ?ÿ?ÿ?ÿ?ÿ N414523.637 W1123723.250?ÿ 161790.0
There is no such thing as "nearby" CORS, unless you consider 100+ kilometers "nearby."
OPUS_RS DOES come in handy from time to time though (for horizontal).
?ÿ
