Traversing after free station

Depends on what you're doing. Are the two points you're resecting from good known control? Are you checking a third independent point? Are you just shooting out one traverse leg to do some topo? Are you staking a building? Are you going to traverse a complete loop and close out on the initial resected point? Whenever someone tells me that "it's just the way we've always done it", I just want to grab them by the neck.

The explanation of "that's how I was taught" doesn't help at all. You obviously have control onsite that may or may not have been previously adjusted. By setting your initial traverse point via resection, what you have is a hanging leg or loop that is outside of the original network.

Is that a big deal, well, maybe or maybe not, that would depend on the work that you are doing off of your fresh traverse and how many check ties you were able to make as your fresh traverse progressed. When traversing, it is never a good idea to run an open leg or a floating loop. Best practice is to start off two known points and close on two known points so that the new traverse can be adjusted to the original work.

I'm sure that others will have a different opinion but my view on resections is to only use them as a last resort.

As others have said it depends on what you are doing and what the project entails. The standard "that's the way I was taught" is a garbage answer. This sounds like the rabbit hole of "we only need topo for this project" then it's into construction and everyone is scrambling to justify the additional time and expense to "do it right". That said ~ resect all you want, but if you don't have sufficient checks in the field before returning to the office good luck. All I can say is Check, check, check, confirm accuracy requirements, rinse and repeat.

I believe it comes down to having a closed traverse whereby each leg of the traverse is dependent upon the other legs with the intention of closing back in to the starting point of the traverse and having a closing angle that would allow for the traverse angles to be balanced and amount of closure computed (i.e. 1:5000)

Properties of closed traverse: The sum of measured interior angles should be equal to (2N - 4) × 90°, where N = number of sides of the traverse. The sum of measured exterior angles should be equal to (2N + 4) × 90°, where N = number of sides of the traverse.

A resected point would not be suited for an adjustment to achieve a particular closure requirement but rather attention is paid to the residuals of the resection to determine the overall quality of the computed position where high residuals would point to slop in the points used to compute the resection.

Hope that helps some.

"All I can say is Check, check, check, confirm accuracy requirements, rinse and repeat."

Well said.

It very much matters what your scope of work is.

Personally...for 90% of the scopes I am involved with, I would set the new point by resection; then, occupying the new resected point, backsight the point behind you in the prior traverse and stake to the foresight on the previous traverse and save the stakeout data; then, again occupying the new resected and backsiting the previous point, relocate the foresight from the prior traverse.

For 9.5 of the other 10%, I would occupy and backsight the last sequenced pair from the prior traverse and re-traverse until I landed on the next sequenced pair.

For the remaining 0.5%, I'd re-traverse the entire prior traverse.

Note but ignore all residuals because if it was a closed loop, the traverse should have been error adjusted and balanced. You're residuals will be off a smidge no matter what you do.

Hopefully this helps

Resection is a tool just like other methods. Knowing how to use the tool correctly is what's important.

Your party chief started working at a time when it would have been difficult to incorporate a resection into a traverse that was being adjusted by the compass or traverse rule. With Least Squares a resection can be easily incorporated into a networked traverse. The key to traversing is redundancy. You need to resect into multiple known points, just as when traversing you should be tying in the same points from multiple traverse points.

You might want to start with a modern elementary Land Surveying Text book. Ask some of the younger guys on this board for recommendations. The newest elementary text book I have is over 40 years old.

Like others have said when someone's only explanation is "that’s the way he I taught." it's time to dig deeper. You want to not only know how to do something, but also why it is done that way.

It's a weaker way to collect positions. This comes from a surveyor that's been resecting for 45 years and had no problem starting a job by resecting two unlocated property corners and using them as the basis for a forward traverse while not occupying them. Calculating it all with an 11C HP and field book.

Today will I do that? Nah, not very often anyway,,,,,,it's all about using GPS and setting up on already located control. If your PC says don't do, you should respect his authority, sit down and work through the math and see exactly how it all works. I think you may reach an epiphany why it's a no-no for them.

Even in my big book of DOT surveying requirements that's not allowed. So, when working for DOT we don't do it. I respect their authority, heck they pay me. That's lots of authority.

Visualize the procedure for a classical traverse. Set on a known point, backsight a known point, set and occupy forward points till you return to the beginning point, or tie into a third known point.

Then close out the traverse by occupying the beginning point a second time, or the third known control point. The angles are turned to finish out all the elements of a "closed" traverse. And if you really want to do it right shoot the distance both directions (very important in big traverses).

The traverse is then adjusted; when there are cross ties, those should also be turned through, if they aren't turned through less weighting should be applied to those connections during an adjustment.

With a resection there are no closed angles, there isn't a second set up to tighten up the point. Even if you're resection using multiple control points, there is still the weakness derived from the procedure. If you want to use resection points in a traverse at least occupy a tie in point and close those angles. However, then you will have a classical traverse with some cross-ties.

There are circumstances where I would be comfortable traversing from a resected position, and some where I would not be. To be comfortable I would first need to have a strong resection from well established and adjusted control. I would need to be resected from at least 3 well spaced control points, and the residuals reported would need to be small. I'd reset the backsight on the most distant of the controls before traversing to another point. I'd need something independent to check into when I set up on the traversed new point. And, finally, I'd want the accuracy needs of the new point to be relatively low.

I routinely resect instrument positions. Most often I do not set up over
a mark when doing so. That would be a problem if I were to traverse
from that position - no backsight.

Resection (of the modern sort) is a relatively new thing in our business and a lot of guys are just not comfortable with it. It works best when the site control is set with resectioning in mind, and is well spaced, well monumented, redundantly tied, and adjusted. Tight.