Level Stadia Tacheometry Software first created
27/10/09 - last modified
27/10/09 Page Author: Ty HarnessIntroduction
If you've got an electronic theodolite or Total Station then you don't need this software because you've probably got more functionality already built into the theodolite.
Some surveyors will probably prefer to fill out a field book and again there's no point in reading this.
LStadiabeta1 is a simple application to record levels taken from a dumpy level or theodolite. Set up your dumpy level so the telescope is level and focus on the staff. Most levels
have 3 hairs: upper stadia, lower stadia and level hair. Take each of those readings and fill them into the respective box in the software. Figure 1 shows a screen shot
of the LStadia software.
Figure 1a - LStadia1 screen shot b)View of Staff through telescope
Press the calc button and the mean of the upper and lower
hair is calculated and should equal the level hair- if it doesn't then the staff may not be plumb vertical or you've miss read the staff. Flap your arm at the staff man and see what hand signals he sends
back. The height difference between the upper and lower hair is multiplied by the stadia constant (usually 100) to calculate the distance to the staff.
Click the TP box if the reading is a turning(or change) point. Click the Pos. Datum box if you think it's a possible datum for the levelling survey so back in the office you can calculate a reduced level (RL).
It may be a concrete curb or an Ordnance Survey bench mark or basically something that's fairly permanent so others can check your survey in the future. If you can find an OS datum then your
levels can be calculated back to the height above mean sea level. The time of the reading will be saved automatically so make sure your PDA has the correct time set. It's always worth making notes about
a particular reading. You can add descriptive notes by pressing the notes button.
Figure 2 - Adding notes to a reading
When you're happy with the level reading then press save and give it a meaningful file name (say) pos1A i.e. staff position 1 level station A.
Always plan out on paper roughly the station positions and levelling points before setting off and try to level back to the same point (a closed survey). With a closed survey you can spot an error
and compensate for it. All books[1,2,3] on surveying detail the levelling procedure far better than I have here.
Wave your arm madly to indicate to the staff man to move on unless if it's a turning point the staff man stays put and the you (the level man) move the level to the
next station. You can shout or use
a 2 way radio rather than semaphore if you prefer.
When you get back to the office you can recall any of the readings by reopening the files. Fill out a field book or add your results to a topographic map or
section drawings etc.
I'm working on some software to print out nicely formatted levelling surveys which will be available soon.
Downloads
Note you need to be a full user of the Ty Harness Sheet Metal software. Log in to the members area and download from there.
There's no dedicated installer for these products at the moment.
Download and unzip the archive folder. You can identify the PC or PPC version because PC and PPC is appended to the filename respectively.
Copy the PC file to a handy folder (say) c:\surveystuff\Lstadiabeta1.exe and just double click to run. Use
ActiveSync/Device Center to copy the PPC version to handy folder on your device (say) /CFCARD/Lstadiabeta1PPC.exe and then just tap to run.
System and Device minimum requirements
PC: XP SP3 {you'll need the .net compact framework libraries - There's a good chance you've already got them installed. If not then
you can download from Microsoft(TM) but make sure you've got ActiveSync 4.x installed and your device synced up so immediately
after installing on the PC the required device libraries will then be installed on your PDA device.
