Subject: Re: Question from layman
From: artworxart@aol.com
Date: 19 Nov 1996 00:07:11 GMT
In article <5684g3$miu@noc2.drexel.edu>, sg92pxzh@dunx1.ocs.drexel.edu
(Alan Shein) writes:
>There are other stakes, however that are marked "T4", "T5", etc., and
>have no round pegs. What are these "T" stakes"? And, what the heck, what
>are the other ones for? How come I can only find one "Easement" stake?
That sounds like the way I mark water line "T" 's for instilation. but ask
your neighbor to be sure.
ART
DCI Little Rock
10809 Executive Center Dr. Sw. #210
Little Rock AR 72211-6021
ArtWorxArt@aol.com
Subject: Re: property line dispute
From: ou81tuu@aol.com
Date: 19 Nov 1996 02:45:34 GMT
In a message dated 96-11-16 14:03:34 EST, you write:
<< >Well I sure hope not. Surveying for the most part is an exact science.
(Most Surveyors I know would take exception with the claim of "exact
science" - it ISN'T!
>We typicaly don't use a house for a monument so I don't think you'll get
>far with that one.
Typically, no - But if an old deed, map, as-built or someone's field
notes show a tie to the house corner, it may very well be the best
available evidence of the original corner/line, similar to a bearing
tree.
>**********************************
>* Rick Turner LSIT *
>* San Diego California *
>* USA *
>* OU81TUU@AOL.COM *
>**********************************
(Been surveying for 30+ years, registered in several places.)
>>
Mr. Anderson I appreciate your criticism of my reply. The orig. post
asked for some advise about a property line that had two different
bearings on the same line. He was questioning how the surveyor had decided
what bearing to use, if he had just pulled it out of his hat( so
to speak). My reply, that surveying FOR THE MOST PART is an exact science
cannot be more than fitting for someone who is inquiring on how we
re-establish subdivision lot lines.
As for telling someone that we TYPICALLY don't use a house for a
monument is also a very fitting. Thinking that because he found a tie
somewhere on a plat to his house, that that will discount a subdivision
map with bearings & distance is not what we want home owners to think.
Case in point is the gentleman who has had a title problem becuase of a
mortgage survey that has conflicted with another. When was the last time
you saw a tie to a house on a ROS or one called out on a legal. I'm not
saying that It doesn't happen, I'm just saying that for the year that his
sub. was created it seems HIGHLY unlikely.
I have found in reading Q. from home owners on-line that you don't
always qet the whole story and in the same note, respondents such as
yourself don't always read over responces with the intent to observe,
learn and respond but rather read to critique. Again I value your
criticism, but I would urge you to please re-read the orig. post and my
responce again.
P.S. Experience says very little to me, some of the worst surveys
that I have retraced were done by surveyor's older than me. So unless you
started when you were 2 you could be there. ( Just survey humor )
P.S.S. Reg. in several states ? Haven't been caught yet ?
**********************************
* Rick Turner LSIT *
* San Diego California *
* USA *
* OU81TUU@AOL.COM *
**********************************
Subject: Re: GPS vs Traditional Surveys
From: "J. Anthony Cavell, PLS"
Date: Mon, 18 Nov 1996 22:32:02 -0600
rschaut@aol.com wrote:
>
> The fundamental function of a traditional survey is to provide
> information to both the immediate client and some future interested party
> who may need to retrace the boundary of a parcel of land. Of the two, the
> future need is the most important. When information provided by GPS
> equipment is accurate enough that the location information from one
> manufacturers equipment can be plugged into another's with the reasonable
> certanty that we will be led to the monument, (not near but to), then GPS
> could be used to supplant traditional survey techniques. I would like to
> see twenty points within a one-quarter mile square be located by GPS
> equipment. Then, make two copies of the field information. Delete five
> points at random from the first copy and another five from the secon.d
> Then adjust each set of data independently. A comparison of the data for
> the ten common points would be very interesting, and, if consistent, would
> probably change my mind about the usefulness of GPS technology.
>
> rschaut@aol.com
The comparison of data from appropriately collected data sets would
probably,
then, change your mind. But I hope not. Appropriately collected data by
many
methods may meet this test. The professional's opinion should remain
paramount.
GPS can do many seemingly miraculous things. So can a modern theodolyte,
EDM,
etc. All are tools for the collection of evidence.
This is fun. What IS a surveyor, an engineer who measures, a lawyer who
knows
boundary law, a mathmatician who understands error analysis, a
philosopher
who can read others' words and decern their meaning?
Thanks,
--
J. Anthony Cavell, PLS _____ _____
http://www.net-connect.net/~gpsman/ /_____ / / @ \ /____ /
Navigation Electronics, Inc. /_____ /===(@ % @)===/____ /
200 Toledo Drive /______/ \ @ / /_____/
Lafayette, LA 70506
Subject: Re: Carrying Angles
From: Creagh_Ferguson@msn.com (David & Lorri Ferguson)
Date: 19 Nov 96 02:05:04 -0800
It is ludicrous to say that wrapping angles can yield equal or
better accuracy than direct and inverted readings with ANY
instrument. Wrapping angles does not address mechanical
eccentricities present in EVERY transit, theodolite, total station,
etc. It can be used at best only to help eliminate blunders.
Several surveyors in my locale use that method; I have never heard a
compelling argument for using it, even with the so-called "repeating"
theodolites. No instrument is perfectly collimated.
Consider this: if the reticle is out of line, you can wrap an angle
a thousand times and think you have a good average, but you will be
wrong. Invert the scope and you will discover any problems you might
have with the crosshairs. Even electronic sensing theodolites and
total stations that have multiple sensors on the plate can do nothing
to correct collimation error. That is why they have capstan screws
in the eyepiece.
If you are going to bother to turn an angle multiple times, INVERT THE SCOPE!
David Ferguson, PLS
Creagh_Ferguson@msn.com
Subject: Re: 'Double-ing(?) angles with a total station
From: Melton Wiggins
Date: Mon, 18 Nov 1996 17:40:01 -0800
> "Modern instruments make VERY accurate measurements.
> We no longer have a need for doubling."
>
> --> I made that statement when I got my first Wild T1 in about 1973.
> I was right then and am still right.
>
> Doubling does NOT increase the _accuracy_ enough to warrant the effort.
>
> The REAL reason to double is (and always has been) to eliminate People
> Errors.
>
> 1. We ALL make transcription errors. It is Very common to swap numbers,
> write unclearly, record the vertical instead of the horizontal, . . . .
> The list is endless. "I am very careful and don't do that": BS, we are
> human. "I use a data collector": not out of the woods yet!
>
> 2. We ALL make pointing errors. In the best of conditions we get
> complacent and make silly, sloppy errors; in tough conditions we can be
> mistaken. Pointing to the wrong sight can and does happen, pointing a
> little off the target happens too.
>
> A bad double tells you that you have an error someplace. This is
> probably the only way the error can be found. Balancing a traverse does
> no more than spread the error thru your Good work.
>
> **>>> Don't Skip Doubling, you will screw up, guaranteed. <<<**
>
> We are getting lost in technology and forgetting real life conditions.
>
> ----- (you may replace "doubling" for "redundant independent
> measurement" at any point in this discussion) -----
>
> --
> Peter Ehlert mailto:petere@sonic.net
> Oooo.
> .oooO ( )
> ( ) ) /
> \ ( (_/
> \_)
> Sea Dance Internacional, SRLdeCV
I agree absolutely. I want a full repetition of each angle and
distance. Usually I am recording data manually in a field book, and I
like to double check what I recorded the first time. I have never had to
rerun a traverse due to instrument error, but I have due to human error.
Melton Wiggins
Subject: Re: Carrying Angles
From: jhframe@dcn.davis.ca.us (Jim Frame)
Date: Tue, 19 Nov 96 04:37:11 GMT
In article <00009606+000006ba@msn.com>,
Creagh_Ferguson@msn.com (David & Lorri Ferguson) wrote:
> It is ludicrous to say that wrapping angles can yield equal or
>better accuracy than direct and inverted readings with ANY
>instrument. Wrapping angles does not address mechanical
>eccentricities present in EVERY transit, theodolite, total station,
>etc.
It's been quite a few years since I've used a repeating instrument (Wild
T-1, mostly), but the standard procedure we employed for turning
multiple angles included alternate direct and inverted readings. In
other words, the mechanical idosyncracies of the gun were effectively
being removed anyway, and winding up the angles produced a more precise
result than the least-count of the instrument would allow on a single
turn.
Nowadays (3" total station) I usually turn one direct and one inverted;
sometimes on long shots I'll go for two sets of each. The minuscule
difference provided by additional angles is generally insignificant
compared to errors from other sources.
---------------------------------------------------------------------
Jim Frame jhframe@dcn.davis.ca.us (916) 756-8584 756-8201 (FAX)
Frame Surveying & Mapping 609 A Street Davis, CA 95616
-----------------------< Davis Community Network >-------------------
