I am considering purchasing a couple of Promark 2 units...is there any reason I shouldn't? FYI: the surveying work that I do for myself is part time and can't justify the costs of a new setup. Also, can you purchase replacement antennas for the Ashtech Precision GPS units?
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Thank you!
Sorry guys, disregard the antenna question.?ÿ
I loved the Promark 2 in its day. Great performance. Great value. But I would urge against it unless you just really cannot afford better.
The Promark 2 is GPS L1 only. Even in its day it was a compromise as better (more expensive) receivers tracked GPS L1/L2 which extends range and decreases the required observation time significantly. Glonass tracking was available also, but perhaps less significant because the Glonass constellation was waning then. Today GPS + Glonass L1/L2 is the minimum. The most capable systems of today track GPS + Glonass + Galileo + Beidou, and track multiple signals from each (not just dual frequency). You're talking about technology that is 20 years old now (hard to believe). Imagine other technology that was around 20 years ago and where that tech is today (phones, tv's, computers, etc.).
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If it was the only GPS I could afford, I would take it as any precise GPS is better than no GPS, but the time savings with better systems for only slightly more cost will be huge. You cannot use the single frequency data with OPUS, for example (minimum requirement is dual frequency).
I remember reading that it was RTK capable (or was it another model?). At that time, RTK on L1 units was kind of new. At least in my part of the earth.?ÿ
One thing to check before buying old GPS receivers is the installed firmware. I think since its release, we have undergone several leap second adjustments. The GPS receiver if not given an updated firmware to handle these leap seconds would render them next to useless. I have some old ashtech receivers with old firmware installed that would work together with other similar units on similar firmware but would not process with other newer RINEX data. These usually would have time recorded in 1999 or earlier.
It is RTK capable, but you might prefer to use the short static method. I use several PM 2s regularly but I also have an L1/L2 receiver that gets me an OPUS solution. However on most projects the typical surveyor does, the L1 vectors between various points is more than precise enough. The only advantage of modern GNSS receivers is that less time is required. I have yet to do any survey project where I could get the total station field work done in less time than it takes to get precise L1 positions, so why worry about getting faster.
Other antennas can work with ProMark 2s but you have to know that those 2 AA baterries are somehow boosted to output about 6 volts to run the antenna. Other antennas may require more juice. Using a 12 volt battery to input power through the pole cradle I have gotten L1 data with L1/L2 antennas, but that is not recommended, I just had to see if I could do it.
Paul in PA
We were not allowed to mix-matched equipment unless it came directly from the survey head. Guess they were afraid we would screw the electronics if there were any problems with the voltage limit from different equipment. You own your own company I would venture to guess @paul? That was one of the problems being a surveyor. You can't start your own company because the equipment was so expensive. I think it was only in the 90s that prices started to come down when Chinese sellers were able to copy from companies that hired them as outsourced manufacturers.
The three ProMark 2s I bought back in 2002? were the most cost effective and convenient electronic equipment I have ever owned.
Paul in PA
I contacted btaylor privately, and after some discussion sold him my 3-receiver ProMark2 setup, shipping them off today.?ÿ I've been seeing them sitting on the shelf for a long time now, realizing each time that I have no reason ever to use them again since I have plenty of dual-frequency equipment, but until now I couldn't quite get motivated enough to sell them.?ÿ I let them go for what I believe is a pretty attractive price, and am happy to think that someone will start getting some use out of them again.
P.S.?ÿ 10% of the selling price went to support this site.
Sorry, haven't been on the forum in a few days. I did purchase 3 PM2 units from Mr. Frame and have used them on a project already. Now, I'm having trouble getting the data processed. When I compute VRS, it successfully downloads raw data files from 3 stations, but then freezes up when it tries to download the data, so I can't process the data. This is my first time processing GPS data, so I am definitely not a guru, but I watched Mark Silver's tutorial on youtube and followed what he did exactly, but GNSS Solutions is locking up every time.
Ashtech solutions ran well on an XP machine. You may want an older 32 bit (I think) machine for that.
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