UK Caving
TECHNICAL FORUMS => Surveying => Topic started by: SamT on January 25, 2009, 09:40:36 pm

Ok  trying to get to grips with survex.
The notes I've got are in degrees and minutes (done with a dial)
for example  they are written
Tape Compass Clino
3.2m 45deg12' 15.9deg
etc..
so I've got to use the *units command.
my guess is
*units tape meters compass mins clino degrees
so therefore would i right..
1 2 3.2 45.12 15.9
:shrug:
I find the manuals hard work  and Im an IT professional. but getting there.

i would have guessed converting Minutes into decimal fractions of degrees

An interesting question that is certainly not covered by the Survex documentation.
Given that if one specifies "FEET" then the default is decimal feet rather than feet and inches then I suggest that a quick and dirty fix is to as Cave_Troll suggests and do the conversions yourself to decimals of a degree.
A second possibility is to sign up to the Survex email list and pose the question there; doubtless an authoritative answer would then arrive, probably from Olly.

from the manual...
Example
*units tape metres
*units compass backcompass clino backclino grads
*units dx dy dz 1000 metres ; data given as kilometres
Description
<quantity> is one of TAPELENGTHCOMPASSBEARINGCLINOGRADIENTCOUNTERDEPTHDECLINATIONXYZ
Changes current units of all the quantities listed to [<factor>] <unit>. Note that quantities can be expressed either as the instrument (e.g. COMPASS) or the measurement (e.g. BEARING).
<factor> allows you to easy specify situations such as measuring distance with a diving line knotted every 10cm (*units distance 0.1 metres). If <factor> is omitted it defaults to 1.0. If specified, it must be nonzero.
Valid units for listed quantities are:
TAPE, LENGTH, COUNTER, COUNT, DEPTH, dX, dY, dZ in YARDSFEETMETRICMETRESMETERS
CLINO, BACKCLINO, GRADIENT, BACKGRADIENT in DEGDEGREESGRADSMILSPERCENTPERCENTAGE
COMPASS, BACKCOMPASS, BEARING, BACKBEARING, DECLINATION in DEGDEGREESGRADSMILSMINUTES
(360 degrees = 400 grads (also known as Mils))
Defaults are: Metres, Degrees, Degrees respectively.
so Im sure there is no need to do any conversion (on the hundreds of hand written survey notes I have)

OK Sam, as I said if you specify "FEET" you get decimal feet, nowhere there does it tell you how to specify feet and inches, does it.

Having said that, I'm sure you can get a spreadsheet to do it for you & then just paste the results column into your survex file.

BTW
Larry Fish's Compass will allow you to enter both "feet and inches" and "degrees and minutes". It then stores the info as decimal feet and decimal degrees, however.
As an aside, Compass also allows you to distinguish between the International Foot and the US Survey Foot The former is 0.3048 m and the latter is defined as 1200/3937 m, which is equivalent to 0.30480060960... m. Now, how many of you guys survey to sufficient precision to worry about that?