General timeline when bearings started changing from D?øM' to D?øM'S"

1985 - 1990 in general. Whenever total stations and data collectors enabled 1" display.?ÿ

That sounds right to me.?ÿ Reporting to the second has always been viewed as a joke by me as I started out with gear that could not possibly get to the nearest 5 to 10 seconds no matter how hard you tried.

We were running 1" and 2" Wild instruments in late 70s early 80s.?ÿ I would say its more right around 1980 as a rule of thumb from my experience.

OK Minimum Standards (circa 1985) state all surveyed bearings to be DMS on plats and surveys.?ÿ?ÿ

In California, my experience is DMS and nearest hundredth has been the prevailing convention since at least the 1950s.

The precision of measurements is not the only consideration.?ÿ The precision helps to reconstruct the Survey Map coordinates which were typically done to the nearest hundredth, at least on the Traverse Sheets we have in our files.

1956:

(It's faded because the stupid scanner we have in the office does that when I forget to tell it "photo" so it doesn't try to "fix" the color balance. It routinely outsmarts itself)

It's all kinda silly. Tape and transit surveys were only good to a few hundredths and maybe 20'' at best.?ÿ Geodetic observations with good targetry and instruments could get to +-5" but it required precise invar taping or even iced rod trays to get to similar distance precision when doing triangulation networks.

The EDM revolutionized things and made accurate angle observations less critical, and of course GPS trumps every terrestrial observation over a few miles concerning accuracy. Why the reported DMS/0.01' accuracy required for record maps is a conundrum, obviously the surveyor cannot measure that well but reports his/her map as absolutely good to the hundreth and the second.?ÿ It's a covert lie we all make when we record/file a map.

Getting paid to lie.?ÿ That's what it is.?ÿ We could run the same series of shots a dozen times and never get the same results to the nearest second and 0.01' on every side of the boundary.

The vector based presentation originated from when surveys were actually run that way, corner to corner. Since we donƒ??t actually survey like that coordinates would make more sense.

Posted by: @dave-karoly

The vector based presentation originated from when surveys were actually run that way, corner to corner. Since we donƒ??t actually survey like that coordinates would make more sense.

I would favor stating whatever form was actually measured. Turning angles and then stating bearings obscures where the errors were most likely.?ÿ Converting GNSS coordinates into bearing and distance obscures the picture.?ÿ Turning a traverse into coordinates likewise.?ÿ?ÿ If you measure with a lot of redundancy and do a LS fit, then any form would have similar veracity.

Coordinates need good metadata to be most useful.

@bill93 imagine showing the actual survey, I mean the real survey, the post processed vectors, RTK vectors, traverse ties. That would be interesting.

that is essentially what they did in the 19th century, at least thatƒ??s what they say they did.

Bought a Kern DKM2-AE (1ƒ?) theodolite from Ben Meadows in Atlanta, Georgia, in 1968. Became licensed in 1971. Bought Wild T2/Distomat Di 10 from Florida Level & Transit in 1972. Just reviewed several of my old maps from1971-1973 era, and all of them were to the second. I'm certainly don't believe I was (then) starting something new.

@mike-marks?ÿ you said "geodetic observations with good targetry and instruments could get to +- 5""?ÿ I find this very hard to believe. Can you explain where you got this information. I have seen more that one private surveyor (in the old days) who thought they knew what they were doing (trying to do geodetic surveys) and get what you are talking about. But I have seen plenty of geodetic surveyors who knew what they were doing get way better than +- 5". Using a Wild T2 Theodolite in the service myself and 2 other observers could close triangles with sides up to 9000 meters to one second or less. Very seldom were we at the 2 second mark (that's the sum of the 3 angles in the triangle). If we ever got above that we knew that something was wrong.

JOHN NOLTON (U.S. Marine Corps 1961-1970)

@john-nolton John this is a water cooler conversation, you are turning it into a technical symposium?ÿ

@dave-karoly?ÿ Sorry Dave but that is not true. If you read my post above again you will see it has a?ÿQUESTION?ÿin it for Mike Marks.?ÿNO?ÿone else has to make a comment or answer my post above; just Mike Marks.

Posted by: @john-nolton

@mike-marks?ÿ you said "geodetic observations with good targetry and instruments could get to +- 5""?ÿ I find this very hard to believe. Can you explain where you got this information.

Off the top of my head ????.?ÿ Agreed 1-2" is achievable.

Sometime post WW2.?ÿ

Here is a example from 1953:?ÿ

As you may note there is a mix of nearest minute and seconds displayed. I would guess that since the bearing with the seconds is 30" it's more or less displayed as 1/2 a minute.?ÿ

Here is an example from 1975:

Full on seconds, and I can't recall seeing any subdivision plats after 75 that are in minutes.?ÿ

?ÿ

@mightymoe?ÿ

On a 200 ft line bounded by a couple two bit rebar WHY

The number of seconds is entirely dependent on the rodman's brief determination by eyeballing the monument, whether railroad spike, 5/8" bar or mag nail plus the ability to keep the rod from wavering while staring at the level.?ÿ Typical subdivision lots with lot lines shown to the second are laughable.

It looks like around here some switched to greater precision by 1980, but when I audited a surveying course in 1982 I was given (an undated) copy of the state standards that still called for 0.1 ft and 1 minute resolution or better on plats.

Our class problems were usually given to quarter or half-minutes and tenths of a foot.?ÿ I believe a field exercise used a theodolite but no prism for EDM (as low-ranking party member I was guarding a target at a crossroads from traffic and didn't get to play with the instrument).

My brother bought a rural house (stand-alone parcel created before 1980) and then some of the adjacent lots of a rural development platted January 1980. His lots are pasture and woods; the rest of the lots have "mobile" homes.?ÿ He thinks the house and subdivision were separated from the adjacent farm at about the same time, but the descriptions don't mesh so I'm pretty sure they were not done by the same surveyor.?ÿ

The house deed (courthouse can't find a plat) gives bearings all rounded to 10 minutes and distances to tenths of a foot.?ÿ The plat of lots is dated January 1980 and gives values to seconds and to hundredths of a foot. Both close very well mathematically (after reversing a couple digits in the deed), showing they were office adjusted. They differ on the length of the common line and make different assumptions (measure to road C/L vs section line).

I'd say the surveyors didn't use a theodolite or EDM as I don't think they were even meeting transit and tape standards. My measurements while locating some of his corner monuments should be good to a tenth of a foot, but disagree with record by over a foot in a few cases, and there are two distances (each side of corner where rebar was found horizontal near newer fence post) where the records add up 3.8 ft?ÿ more than my measurement if you believe they actually share the supposedly common line. Slope chaining?