Scope of calibrate directive
In a file of centerline data - What is the scope of the "calibrate" directive? If "calibrate" is specified at the top of a file, does its effect end at the end of that file? Can "calibrate" be specified partway through the shots? Is there a way to reset the effect of "calibrate", similar to the way "flags splay off" can be used? I have a file of centerline data where most - but not all - of the length measurements need an offset added. We had tails on the DistoX devices but forgot to change the internal setting to adjust for it. Most shots need 74mm added - but not all! We found one DistoX which was correctly set. Fortunately the shots it was used for are easily identified. There are several other files of centerline data which do not need offsets, and I want to make sure the effect of "calibrate" is limited to those shots where it is needed. Thanks! -- =============== Bill Gee
In a file of centerline data - What is the scope of the "calibrate" directive? If "calibrate" is specified at the top of a file, does its effect end at the end of that file? Can "calibrate" be specified partway through the shots? Is there a way to reset the effect of "calibrate", similar to the way "flags splay off" can be used?
Hi Bill The scope of calibrate is the current centreline block of data. The start and end of a file is not relevant to Therion's scopes where that file is 'inserted' into another using the input statement. It is endcentreline and endsurvey that defines the end of a centreline or survey scope. I have only ever used calibrate at the start of a relevant centreline, so have not tested Tarquin's suggestion, but I'm sure you have Tarquin :) Subject to that caveat, the answers to your other questions are all 'yes'. My observation from small datasets you have supplied Bill, is that you have a single centreline for an entire cave. Where this is the case, it makes it less convenient to specify parameters that naturally only have relevance to a particular survey team on a particular day. One work around might be to use a group - endgroup pair to encapsulate the data where you want different calibrate settings to the rest of the cave (Therion Book page 21). One caveat is that I have found that calibrate only works for some parameters, calibrate should be one of them, I'm just not sure. Alternatively, my approach, in the case of your PracticeMine example shared recently, would be to take the centreline, units, endcentreline statements out of PracticeMine.th and replicate these, along with any calibrate statements, into your data.txt files. That way the metadata relevant to a day's survey can be at the top of the page when you are viewing that day's survey legs. Bruce
I have only ever used calibrate at the start of a relevant centreline, so have not tested Tarquin's suggestion, but I'm sure you have Tarquin :)
Indeed. I used it while surveying a sump, pointing the laser into it to measure the depth, calibrating the length for the refractive index of the water to get the actual depth (and yes, I did all the maths to work out how much was in water and how much was in air, because of course I did), rather than what the Disto thought it was. I interleaved the data with the relevant: 1 2 3.4 56 -7.89 calibrate tape 0 0.96 2 3 7.8 90.1 -78.9 calibrate tape 0 1 2 4 1.2 34 5.6 Part way through the data, one calibrate command sets it to a new value, and then later another sets it back to defaults ("0 1" in the case of tape). Other centreline blocks already reset to default without needing to be explicitly stated, so they are not affected. (And for those who care, yes, of course the refraction also altered the clinometer readings, but I was only using them to splay the walls and measure the deep spots, so I kept it mostly vertical, and pretended not to care about the imperfections!) Sent from my phone earlier, so I couldn't check the specifics.
participants (3)
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Bill Gee -
Bruce Mutton -
Tarquin Wilton-Jones