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g.p.s.
Posted by mike thornton on December 1, 2016 at 8:59 pmA FRIEND AND I BOUGHT A SET OF HIVER-V TOPCON G.P.S. RECEIVERS AT THE SAME TIME ABOUT 4 YEARS AGO AND UPGRADED THE DATA COLLECTORS WITH TDS SOFTWARE. I HAD COMPLAINED OF THE PREVIOUS HIPER PLUS LYING TO ME AND WAS TOLD THE HIPER-V WOULD NOT DO THAT. AT NUMEROUS TIMES, WE HAVE FOUND IT GIVING US BAD INFORMATION. I TOOK THREE SHOTS IN A STRAIGHT ROAD THEN INVERSED BETWEEN THEM AND FOUND TWO OF THE SHOTS WERE 6 TO 8 FEET OUT. SHOT IT ONE MORE TIME THEN CHANGED DATA COLLECTORS WITH THE SAME SOFWARE AND IT DID THE SAME THING. WHEN I SET TWO POINTS AND CHECKED THE DISTANCE BETWEEN THEM IT MAY BE 0.3 OR SEVERAL FEET OFF. IT LIES TO ME IN THE OPEN JUST AS MUCH AS UNDER CANOPY. I DON’T TRUST ANY SHOTS WITH IT. EVERY SURVEYOR I HAVE ASKED ABOUT THIS REPLIES “MINE DOESN’T DO THAT”. WE ARE HAVING A HARD TIME GETTING HELP WITH THIS MATTER. DOES ANYONE HAVE AN ANSWER TO THIS OR HAVING THE SAME PROBLEM ?
N.W. Staker replied 7 years, 7 months ago 17 Members · 33 Replies -
33 Replies
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There are many experts here who likely could help you, but I think they will need more information about the procedures you are using to do so.
If you are simply taking a single unit and collecting points autonomously, without post processing the data in some way, such as through OPUS, you are going to experience the problems you are describing. Even if you operate both units simultaneously, unless one of them is on a known reference point tied to a specific datum and you don’t post-process the data to constrain the position of your reference station, you will have problems. What it sounds like you are doing is essentially the same as if you were using a hand held unit collecting individual points, then expecting them to line up or measure (inverse) correctly between them to some high order of accuracy. Simply won’t happen.
The really smart folks will be along soon, but you need to give much more information about exactly what and how you are collecting these positions before anyone will be able to help you. You might also reconsider not yelling at all of us by typing everything with Caps Lock on.
Good luck.
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SPMPLS, post: 401935, member: 11785 wrote: There are many experts here who likely could help you, but I think they will need more information about the procedures you are using to do so.
If you are simply taking a single unit and collecting points autonomously, without post processing the data in some way, such as through OPUS, you are going to experience the problems you are describing. Even if you operate both units simultaneously, unless one of them is on a known reference point tied to a specific datum and you don’t post-process the data to constrain the position of your reference station, you will have problems. What it sounds like you are doing is essentially the same as if you were using a hand held unit collecting individual points, then expecting them to line up or measure (inverse) correctly between them to some high order of accuracy. Simply won’t happen.
The really smart folks will be along soon, but you need to give much more information about exactly what and how you are collecting these positions before anyone will be able to help you. You might also reconsider not yelling at all of us by typing everything with Caps Lock on.
Good luck.
I have a base station set on a known point on my job and tying corners on each survey I do. you can go back and check the same points and maybe find one of them 6 or 8 or whatever feet difference from the first shot.
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Kinda sounds like “it” may be storing FLOAT (or even autonomous) positions. The Data Collector SOFTWARE should have options to warn you when a ROVER position is not “fixed,” even though that (fixed) doesn’t necessarily mean GOOD all of time.
Loyal
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So you are setting one unit on a known point (base station), then locating other points with the second unit while the base is running? I presume you are doing this using a rapid static or static post-processed method, not using RTK? Do you collect a second observation on the rover point while the base is still running for redundancy? Then what do you do with the data you collected?
Again, there are many members here who do this successfully every day. I do not think it is GPS lying to you, but rather the procedures you are (or aren’t) employing, but again, many more details are needed to figure that out.
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The Topcon Hipers with FC200 I used could be setup to accept float positions when it couldn’t fix but float was close enough (like a rough location of a 20′ wide creek). If it is RTK I would wonder if float positions are sometimes being accepted unknowingly by the user.
The other option it is a post-processed kinematic survey style that is not being post-processed.
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Am I to assume you accepted bad data for 4 years and now wish to complain about it?
Have you had any formal GPS education/training to even explain that you know you are having a problem?
Paul in PA
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I think Loyal has it.
There is a setting, that tells it to store ONLY fixed solutions. Or, conversely, it can also accept floats. (if you tell it that is acceptable)
settings my friend.N
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There should be a setting that allows it to show a fix depending on the confidence level of the solution. You should be able to set the confidence level of the fix very high like 99 percent then it may have a hard time getting fixed but the fixes will be significantly better. Or something like 96 percent or even 75 percent. It has been a long time since I have seen where those settings are and can’t point you to where to look but I know they are in there.
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Can you post some examples of your software survey reports? You’re receiving corrections via radio a la RTK? To be frank this post makes little sense. Who wouldn’t test their gear out and resolve the issues before declaring the equipment faulty. I’m sorry. It just doesn’t make sense to me. Like the others have said it sounds like raw autonomous or float positions are being stored without any corrections, unless you were completely under dense canopy or something. What kind ambiguities are you getting while storing these points? Fixed? Pdop? I just can’t imagine someone surveying with gear without first testing it out on a base line or on other known points, at the very least measuring between two points with a TS and then doing same with the RTK gear and comparing results. A tenth or two sure, feet, no dice. Without more detailed info I could only speculate.
Willy -
There has been no mention of a radio being involved, nor any mention of post-processing data. If the OP wants assistance, we need a whole lot more information. If he has talked to other surveyors who use GPS and they say “mine doesn’t do that” he either isn’t really telling them what he is or isn’t doing, or they don’t have an interest in helping him. I find it odd that he joined here today and asked for help (4 years hence) yet has not offered much information to be able to obtain help.
Sounds to me like he is where most of us were 20 or more years ago, thinking the magic boxes are a cure-all, without having any training or understanding about how the magic boxes actually work. His profile says he is licensed in 3 states, so he has some level of aptitude and experience in surveying. I hope he comes back to share enough details to get help without feeling he will be ridiculed. That’s not what this place is all about. His post seems odd on many levels, but let’s wait to be critical. We all started somewhere.
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SPMPLS, post: 401967, member: 11785 wrote: There has been no mention of a radio being involved, nor any mention of post-processing data. If the OP wants assistance, we need a whole lot more information. If he has talked to other surveyors who use GPS and they say “mine doesn’t do that” he either isn’t really telling them what he is or isn’t doing, or they don’t have an interest in helping him. I find it odd that he joined here today and asked for help (4 years hence) yet has not offered much information to be able to obtain help.
Sounds to me like he is where most of us were 20 or more years ago, thinking the magic boxes are a cure-all, without having any training or understanding about how the magic boxes actually work. His profile says he is licensed in 3 states, so he has some level of aptitude and experience in surveying. I hope he comes back to share enough details to get help without feeling he will be ridiculed. That’s not what this place is all about. His post seems odd on many levels, but let’s wait to be critical. We all started somewhere.
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I’m not a new grounded here. Base station with radio doing r t k all fixed solutions collected. You can look at the sky plot and sat info and the Russian sat cut off and on with only American sat showing on screen. It gives me some bad solutions period. Not always but often. I can see that no one else has that problem or some are collecting shots and not checking them. I’ve been complaining to the company I purchase from since the first purchase in 2008. I’ve had plenty of experience after working with the corp of engineers for 36 years starting with Trimble gps. Bottom line this gps equipment gives me bad solutions either because of the units or the software. That’s what I’m trying to resolve ! -
I have seen bad fixes last upwards of 2 minutes plus in bad environments. Maybe spend a little more time and reset the rtk frequently.
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Whatever is going on… You should ascertain whats going on…
If you don’t mind… A few questions…
Does it say FIXED or FLOAT?
When was the firmware last updated? (somebody may have set it to store floats, but the real problem was out of date firmware).Is this unit in regular use?
Do you have the data collector with a FULL key board? Or the little one, with tds?
Do you know how to use topcons software, to look at all the internal software? Do these have memory, for post processing?
Do you have a geoid file, in the data collector?
What projection are you on? Arkansas has 2 zones, north and south.
If you have the projection set badly wrong, it can do weird things… Ie, elev. Becomes horizontal…
Some setting is wrong… Or you are not understanding it.
What state are you in?
Maybe one of us can help. It’s been 3 or 5 yrs since I seriously worked on one of those.
Are you proficient with setup?
Talk to us, and we might figure it out.N
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I’ve never seen or heard of what you describe,,,,,,,,,,,,bad fixes? in the early days once a day, now once every couple of years maybe,,,,,,,,,,,,from what you describe it almost sounds like you are getting ties from another base
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Mike (mightymoe) above may have a valid point… Have you tried a different radio channel? That should help, if it’s what he said.
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MightyMoe, post: 401981, member: 700 wrote: I’ve never seen or heard of what you describe,,,,,,,,,,,,bad fixes? in the early days once a day, now once every couple of years maybe,,,,,,,,,,,,from what you describe it almost sounds like you are getting ties from another base
Latest update always fixed solution. data collector set at 0.08 for horizon and vertical. I have performed state plane surveys in ark, la and ms with the corps. well versed in grid. But always geodetic surveys for myself. Been into too many areas to be getting info from another base. Using nomad or ranger data collector with tds Software. Will lie to you in the center of a paved road in a heartbeat. To the person that stated who would try it out without testing it ! who would spend that kind of money and not try it out ? If it’s not ever shot you wouldn’t catch it off the bat ! No I have not been collecting bad data for four years and now complaining. When you get bad solutions like we do from the first purchase you assume it’s normal or other surveyors are not checking their data. But after talking to other surveyors over the years we realize it’s not the norm. We’ve been trying to get this problem resolved for quite a while.
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Also have tried several different channels because of interference and not getting the range out of the base radio.
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mike thornton, post: 401936, member: 12289 wrote: I have a base station set on a known point on my job and tying corners on each survey I do. you can go back and check the same points and maybe find one of them 6 or 8 or whatever feet difference from the first shot.
Mike, this is evidence of something other than the collection software. Even when the screen is “lying to you” the lies should be consistently wrong. Locations differing from data observed previously from the same setup is indeed a head scratcher. The only thing that comes to mind is, as mentioned by several others, a float or autonomous solution.
There is no doubt in my mind if you actually had the units malfunction in front of a tech from a repair facility they too would agree It is in need of attention. Pack that stuff up and take it to someone asap.
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paden cash, post: 401992, member: 20 wrote: Pack that stuff up and take it to someone asap.
I agree. It aint normal.
Maybe even a cracked component, or loose connection.
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