I am taking a course right now and we are learning how to do sun and polar star observations to get an azimuth and while I see it has its uses I must ask, does anyone here either on a regular or semi-regular basis ever need to actually do this in the field? I know it's on the fundamentals exam however life can vary from tests.
> ..... does anyone here either on a regular or semi-regular basis ever need to actually do this in the field?
Probably not. In my opinion, in doing retracement survey work, a person needs to know how the original survey was staked. Knowing measurement fundamentals is of great value as well. I like the fact that I know how to a solar and a stellar observation if I need to.
Some of the other things you might consider:
Do we need to understand math now that we have calculators?
Do we need to even understand traverse closures or gps and least squares adjustments since we have boxes that do that for us?
Do we need to understand topographic shots when we have data collectors do it for us?
Do we need to understand slope stakes even though they can do machine grading?
One other thing you might consider, since everything is virtually getting robotized and electronic-ized, these days, who is going to program the machines? I think those guys should understand some fundamentals.
Regardless, you are fairly right. The need and use of a surveyor is deminishing. It might even be getting too late to enter the field.
Now's the time to do those things, because you probably will never do them again.
This way you can say you've "been there, done that".
I personally think it's good to know these things instead of wondering what it was all about for the rest of your life.
And if LightSquared gets their way, who knows, maybe it is a tool we will be using again.
> Now's the time to do those things, because you probably will never do them again.
> This way you can say you've "been there, done that".
>
> I personally think it's good to know these things instead of wondering what it was all about for the rest of your life.
>
> And if LightSquared gets their way, who knows, maybe it is a tool we will be using again.
i can remember, not too far back, when my company had only one, single frequency gps receiver. cook with antenna above a triple prism, take a sunshot to that from the remote point, back in the data, and orient to the project. good days
> Regardless, you are fairly right. The need and use of a surveyor is deminishing. It might even be getting too late to enter the field.
I must ask why you think this, as from my understanding the ability to do retracement and understand the earlier methods is not a check box on a data collector (last I checked). There are also the boundary issues that crop up BECAUSE someone just followed the black box or *gasp* staked platted distances & bearings.
To answer your "Do we need..." questions, yes to all except slope staking, that stuff turns my brain to mush and leaves me slack jawed and drooling 😛
I have been hired for two projects in the last 12 months or so where I was hired SPECIFICALLY to check azimuth control via Polaris, both for high dollar antenna orientations. Taking celestial observations is a niche service for sure AND apparently one that is becoming more rare as the older generation retires.
Not something that will get used often probably but if you can learn how, it is worth knowing.
SHG
I asked myself the same question when I was in College.
Then in one of my first job I had after graduation, I was taking sun shots on a seismic job in the Canadian High Arctic. The Party Chief / company owner had a calculator with an averaging (and rejecting outliers) program. It was a very interesting job. I realized the value of the sun shots in a real life context.
Depending on your geographic career destination(s), you might use this type of observations some day. There's all kinds of technologies / methodologies used around the world.
> I am taking a course right now and we are learning how to do sun and polar star observations to get an azimuth and while I see it has its uses I must ask, does anyone here either on a regular or semi-regular basis ever need to actually do this in the field? I know it's on the fundamentals exam however life can vary from tests.
I still make solar observations about three or four times a year. I find them handy for checking angular closures on projects where a traditional closed loop type traverse isn't feasible and where gps isn't an option due to pine forest conditions. Since I use the solar observation less each year I make it a point every 6 months or so set up and practice making one. It helps to keep things familiar.
I still take sun obs fairly regular when traversing in timberland where gps obs are hard to get.
Plus they're easy to field calc and get a starting bearing when beginning a job.
I believe there are quite a few guys in the BLM who still use them as part of their cadastral surveys.
I'll perform a solar observation on every job with the exception of a lot/block platted subdivision parcel. It takes less than 5 or 10 minutes to do and in my opinion "levels the playing field" for weighing the evidence in a boundary retracement.
> I am taking a course right now and we are learning how to do sun and polar star observations to get an azimuth and while I see it has its uses I must ask, does anyone here either on a regular or semi-regular basis ever need to actually do this in the field? I know it's on the fundamentals exam however life can vary from tests.
Absolutely, all the time.
I must say I am surprised and intrigued. Thank you for the feedback!
It seems like I used to do them every day, but it was probably more like 2-3 times a week, but it's been a LONG time since I have done one (not sure when [or where] the last one was).
That said however, I think that it a necessary skill for a surveyor, and one that will always be of VALUE!
Still have a T-2, so... have gun, will travel.
🙂
Loyal
We still do them almost daily.
For retracement work, they are a must. The older the line we are following is, the closer it is to true it seems. Old Lines ( 1850-1920 ) are seldom more that 15 min off true. Think about it, it was not too difficult to sight your compass on Polaris and set your declination back in the old days.
For open traverse work ( pipeline, powerline ) they are the best, maybe only way to check your angles at the end of the run. By doing at least one observation at the beginning and end (we like to do one at least once a day), you not only have a check, but you have something to adjust your angles to.
For large tracts ( 2-5 days traverse )we do one a day so if there is a problem with the closure, we can isolate where things when wrong.
When generating SPC's by GPS, I still can't resist checking against a sunshot.
Solar Ob's are your friend.
Bruce
What equipment and methods do you use? I'm guessing total station with solar filter, sighting on one edge of the sun? Or Roelofs prism? Hour angle or altitude method? Time source?
> What equipment and methods do you use? I'm guessing total station with solar filter, sighting on one edge of the sun? Or Roelofs prism? Hour angle or altitude method? Time source?
Total station with filter, I'm pretty sure it's the hour angle method, sighting trailing edge, 3 direct 3 reverse, circa 1990 Radio Shack time cube, Shot on even minute ( crews can't hang on to a stop watch ) Mean angle average 3.4 seconds
Polaris is relatively easy to observe and calculate but we should keep that to ourselves LOL.
You can put those extra azimuth observations into LS to get directional redundancy on your traverse. If I had a solar filter I would do it too.
You are supposed to be able to find Polaris during the daytime but I haven't been able to find it. Polaris is really simple to observe and calculate plus the time doesn't have to be very precise.
I used to do them on nearly every job.
The extra items I used to do were:
Look up theta, and put it on GRID brgs.
Recompute it 1" of time off, to SEE how much difference 1" made, at that TIME of the day. Usually, I did NOT do too steep of a sunshot, ie, around noon. But, 1" of time was usually 6-10 arc seconds, for the orientation.
Ok. So, now you want to RETRACE my survey, and you discover, that I applied theta, the WRONG way.
My point is that if you knew what I was doing, then you can find my mistakes.
IF you do not know what I was doing, then you may be lost.
I think everybody should learn to survey with a transit and tape, just to UNDERSTAND how the mistakes were made.
Like, the time I found somebody had swapped the witness tags, and put them on the wrong trees....
And, they BOTH generated a location, for a lost monument... that took a bit of working!
RETRACEMENT.
I personally think young surveyors should be required to SURVEY with a compass and chain, for several miles, before getting a liscense....So they would understand, and appreciate how many 1/4 miles are 1316.25', instead of 1320'
N
> > What equipment and methods do you use? I'm guessing total station with solar filter, sighting on one edge of the sun? Or Roelofs prism? Hour angle or altitude method? Time source?
>
> Total station with filter, I'm pretty sure it's the hour angle method, sighting trailing edge, 3 direct 3 reverse, circa 1990 Radio Shack time cube, Shot on even minute ( crews can't hang on to a stop watch ) Mean angle average 3.4 seconds
I bought my Radio Shack time cube around the same time. I'll synchronize my stopwatch with the tone, gives me a little more flexibility to take shots, especially when I'm sighting between clouds passing. Here's a number, 1-303-499-7111, that gives the time also.
