Hiper V vs Hiper V+10 antenna model with OPUS
I have a question into NGS asking for which model they recommend for a 2m carbon fiber rod. No response yet.
The assumption that the two antennas are the same seems incorrect given that they have different part numbers. Why would a different part number be assigned to a unit that only differed by a 10-cm rod?
Attached are the graphics associated with the antenna phase model. While externally they look identical, the internals probably do not. I also attach an extract from an old OPUS static extended solution showing exactly how the tool determines antenna height wrt phase centers.
FWIW: On a related matter, years ago there was a problem due to an antenna manufacturer??s attempt to fix a problem with their unit. It involved a physical change to the antenna??s internals. It was impossible to determine which of the models had the change by external examination. The only way to tell which units had the change was to do so via the serial number. In this case the manufacturer??s model number was not changed to reflect the modification.
I think the whole difference in the phase center is that the adapter is not under the antenna…it’s right beside it. Wasn’t the Hiper V the first Topcon GPS to have the antenna mounted on the bottom of the unit? I always assumed so that they wouldn’t break as much as when they were mounted on the top like the Hiper Lite or GA. Below is a picture of the Hiper V antenna:
https://www.benchmarksupply.com/topcon-hiper-v.html
Also, the ref measurement is to the bottom of the adapter and not the bottom of the mount??? Was that diagram taken from NGS as well GeeOddMike? Are the part numbers because there are some Hiper Vs that did not have the bottom antenna mount?
From the antenna calibrations link on the NGS home page choose browse by manufacturer.
The antenna drawings are from this page. The ??spacer? appears centered not offset.
I think one thing that is confusing is the mark they have labled SHMM. There is a little ledge on the side and it stands for Slant Height Measure Mark. We own an earlier version of the Hiper V called a Hiper II. They look identical. I am assuming that adding the little pole changes the phase center somehow, but I still don’t see how.
I use a 1′ extension when setting up on top of a tripod, I have no clue how that affects anything but so far I don’t have problems. Like someone above noted, there are so many different poles and different ways to setup a GPS unit how can you predict how that would change the phase center.
I am doing a 4 hour session on our local GPS on BM station today, using 2.000 m +.100 m with our other receivers (hiper II) to compare the results.
so HIPER V + 10 + NONE for this one
and HIPER V + NONE for this one
??
@standing-on-the-corner What was your results?
@aaron-k-burns Sorry for the delayed reply. As of now, my testing results are inconclusive.
I have a current project, where we are running 4 types of receivers and digital levels. A few more weeks and I may know something.
I know I am late to the party. I picked up this thread in a search and there are some questions which occur to me.
The pictures I posted above are of an aluminium 100mm extension and a carbon fibre 100mm extension. There is a different consideration due to effect on the internal antenna of the metal pole extension.
For a static survey and post processing I always use the 100 extension with a tribrach and adapter.
I can use the appropriate designation.
My GPS pole is carbon fibre.
Most of the Trimble poles I have seen have an aluminium inner pole within the carbon fibre outer and I am sure there are others.
Surely the extended inner pole has an effect on the antenna height ?
In my opinion there is no way nearfield multipath with a 10 cm piece of metal under the unit can cause 5 cm of difference. Maybe a millimeter or three, but not 50 mm.
I??m planning an experiment to see if things under my GPS antenna affect the measurement of height. I??ll use an antenna mounted 1) close to a metal tripod, 2) with 20 cm of wood added, or 3) with 20 cm of metal tube added. It won??t be exactly on the tripod because I need a layer of masonite and a nut to hold a fixed position for the tube and wood.
Although 10 cm is of more interest on the particular antenna discussed in this thread, the additional height is a little more relevant to me because I often use either on the tripod directly or on a 2-meter metal pole. I figure 20 cm will be enough to see if there is an effect and easier than rigging 2 meters of wood.
I plan to set up two receivers (4000sse) a few feet apart, with one using a TRM14532-00 ground plane antenna as the reference and a TRM33429-00 ??microcentered? as the one in each of the three positions. The choice is because I would expect more effect, if any, without the ground plane. I??ll take maybe 5 minutes in each position at 10-second rate, and process together in Topcon Tools to get vectors between them to compare the relative heights values.
If I get a significant difference then I??ll probably repeat using the 33429 as the fixed reference and moving the 14532-00 ground plane antenna, since that is the one I??ve always used for GPS on Benchmarks.
I??d rather have you throw rocks at the plan now, rather than tell me afterward that I did it wrong. How long for sessions and at what rate would you use? Other comments?
.My conclusion is that I found no significant difference with various things under the Trimble 33429.00 “microcentered” antenna.
Measured height of the nut above an arbitrary reference:
3 mm with 20 cm metal tube
7 mm with 20 cm wood
20 mm antenna on nut
8 mm antenna on nut, repeat
It turns out I set the sample rate in the wrong place in the menus and they were at 10 seconds. I ran each session 20+ minutes, at least 120 epochs. I barely had enough common satellites for the earlier sessions, and more toward the end.
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I know this is an old topic. But thought this might help some of you and seems to make this topic more cloudy
, and I would like feedback if any of you are still watching this forum because I’m not confident in this…
According to this NGS/OPUS response I got, the resulted orthometric height difference is actually .037 meters in the other direction (compared to ARP measured on receiver and NOT selecting +10 option). Not .052 meters as stated earlier in the forum See reply below and my my results from the same log file. This considering the guy from NGS is actually right. Also note you have to measure from the bottom of the the 10cm topcon part. NOT the ARP on the antenna itself if that makes sense, according to NGS.
NOTE: These scenarios were OPUS’d two months ago and I resubmitted them today and are they Precise Ephemeris, not Rapid.
- Scenario 1.
- Antenna selected on OPUS page: TPSHIPER_V NONE
- Measuring point-ARP on the bottom of receiver
- ARP height entered in OPUS: 1.698 meters
- Ortho Height: 427.636 meters
- Scenario 2.
- Antenna selected on OPUS page: TPSHIPER_V+10 NONE
- Measuring point-ARP on the bottom of receiver
- ARP height entered in OPUS: 1.698 meters
- Ortho Height: 427.573 meters
- Scenario 3.
- Antenna selected on OPUS page: TPSHIPER_V+10 NONE
- Measuring point-BOTTOM of 10cm/100mm piece. 1.598 meters
- ARP height entered in OPUS: 1.598 meters
- Ortho Height: 427.673 meters
All scenarios were from one project where we had no recently verified NGS marks and the one we had was in thick vegetation, and we had no cell service to access the network here in Nebraska, so we differential leveled out to open area on a control point, closed, and I OPUS’ed this point 6+/- hours. Scenario 3 was actually the farthest elevation of the three Scenarios I put into OPUS. The mark’s elevation was 427.488 meters from leveling off the NGS benchmark, a difference of .185 meters from Scenario 3, which doesn’t give me a lick of confidence. I need to keep testing this, though.
Hello Quinton,
For the Topcon Hiper_V+None that does not use the factory spacer, the ARP is measured to the bottom center of the antenna (https://geodesy.noaa.gov/ANTCAL/LoadImage?name=TPSHIPER_V%26NONE.gif).
For the Topcon Hyper_V+10+None that uses the factory spacer (part # 51949), the ARP is measured to the bottom center of the spacer as is shown in the drawing that you provided (https://geodesy.noaa.gov/ANTCAL/LoadImage?name=TPSHIPER_V%2B10%26NONE.l.jpg).
As you can see, the ARP location that you measure to is determined by whether or not you are using the factory spacer. If you would like further assistance, please reply to this email.
Regards,
Dave
- Scenario 1.
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