I am not clear on why they call it an "OPUS" receiver. From the web page it looks like it would work fine for any static survey.
I would be interested in it as a static receiver, which is almost all that we do. I have two receivers that are having problems with indicator lights, memory, etc. Those would still work just fine with VRS or RTK.
John,
A friend informed me of this receiver after the GNSS Solutions issue I had last week.
I think they call it an OPUS receiver because it is an L1/L2 receiver, that only does static, and is being marketed for being able to collect static data that is capable of being submitted to OPUS. The price is very comparable to an L1 only receiver, like my Promark3 units.
I am considering selling my Promark 3 units, and getting a pair of these units for static work.
I only use my Promark 3 units for static. I don't do any GIS collection with them at this time. I would like to get into that area, but have not yet explored it too much.
Jimmy
It looks like a knockoff of an R8, but appears to be GPS only (which is fine for static). My only concern is contradicting my "buy American or European" policy. I have not yet bought any Chinese survey gear, which I am fairly sure this is. All my stuff has been Wild/Kern/Zeiss/Trimble, although I did recently purchase a Trimble M3 (which is Nikon, made in Japan) as a backup instrument.
> Huh? That makes no sense.
Assuming good data, OPUS uncertainties tend to fall within a limited range. For most survey purposes that range is too large for points located near each other, but as you extend the distance between OPUS points the impact of those uncertainties gets diluted and falls into the noise range of other survey techniques.
The same concept lies behind GPS height modernization guidelines. The 2 cm standard for stations spaced 7-10 km apart is based on the notion that conventional leveling will produce errors of that magnitude in the same distance. In other words, two points 100 m apart that each have 2 cm of vertical error aren't very useful, but two points 10 km apart with 2 cm uncertainty each can be very useful.
Whether a 1-mile separation between OPUS points is a standard to apply depends a lot on what you're trying to accomplish, but the concept makes sense. At least to me!
Is much bigger than an R8 as it uses a much higher quality antenna and ground plane. However, you are safe John as it does use a Trimble OEM Board internally (is L1/L2 & L2C). BTW, CHC Navigation is the only Chinese company with USA employees, local dealers, and local service centers.
Thanks, Lance. That is very interesting. I note that in their download program (which I tried the demo), it has a default of TRIMBLE 5700 for receiver type.
Do you know if their data format is proprietary or do they release details about it? My workflow is setup to read trimble .dat files format, but I can also read rinex files.
Unlike most users, our use of RTK is very limited, and in any case I have a few receivers that can do RTK but, as I mentioned, are becoming somewhat crippled for static. My 5700 (I always use it as a base for static survey) sometimes refuses to recognize the CF card, and the log data light is iffy as well. One of my 2 R8's has a power light that no longer works. The log data light still works, but I don't know when the battery is getting low.
I'd direct a lot of those tech questions to iGage as they worked with CHC on developing this custom product for the USA market.
I think the product will be released this week, from what I know (using the beta product) is:
1. Internal board is the Pacific Crest BD950, same board that Trimble uses in the 5700.
2. The free software by iGage that automates the upload to NGS also creates RINEX files that you could use in your existing work flow: Go to the configuration tab, change from "Simple" interface to "Advanced". Doing this the RINEX button will display.
> > Huh? That makes no sense.
>
> Assuming good data, OPUS uncertainties tend to fall within a limited range. For most survey purposes that range is too large for points located near each other, but as you extend the distance between OPUS points the impact of those uncertainties gets diluted and falls into the noise range of other survey techniques.
>
> The same concept lies behind GPS height modernization guidelines. The 2 cm standard for stations spaced 7-10 km apart is based on the notion that conventional leveling will produce errors of that magnitude in the same distance. In other words, two points 100 m apart that each have 2 cm of vertical error aren't very useful, but two points 10 km apart with 2 cm uncertainty each can be very useful.
>
> Whether a 1-mile separation between OPUS points is a standard to apply depends a lot on what you're trying to accomplish, but the concept makes sense. At least to me!
Jim et al,
I know that wouldn't come across correctly. I was being fecetious. I understand the principle behind what you're saying. However, my point was what you were saying in your last paragraph. It depends on what you're doing. I've done sessions a lot closer than that, that worked for me.
John
We just had a Oregon GPS User's Group meeting yesterday and a sales rep showed us the receiver. From what he said, it sounds like it would work just fine for your applications. I didn't have plans to do any purchasing so I didn't pay as close attention as I should have. If you are interested, I can get you his contact info. My email is in my profile or you can simply respond here on the board.
We received one of X90 receivers last week and this is an awesome unit! So far I like everything about it. The case is top of the line. The receiver is well constructed. The software is simple and well thought out. Everything about this unit is awesome! Oh, and the price! I am impressed! This is a one button deal so the boss, who is techno challenged, can now get survey grade shots on glo monuments and headgates! I will be using it as a second base when doing static and stop and go with PM3. We have been purchasing equipment from iGage for 7 years now and have always enjoyed the experience!
Norman,
Just playing around with the unit to see if its works. I didn't establish the corner of the World Trade Center some 3500 miles away from the angle spun from these two points. IF I would have, I would at least have doubled the angles with my 1 minute Sears builders transit.
LOL
Geezer