A pyserial derived class for sampling a parsivel disdrometer from ott via python This program is loosely based on the parsivel serial tools form TROPOS in so far that it creates the same netCDF files (which in turn are compatible with cloudnet As such, this repo is underdocummented :-)
Several options are available:
The default is for the file to be sampling for 15 minutes on /dev/ttyUSB0 via the CS/PA pollcmd which returns all data. This is written to self.data based on the code (see manual, spectra is code 93 for example). The data is then written out to a netCDF and a ASDO-like file (with only 1 header instead of one for every record). By default, files are written out into a subdirectory structure of Y/M/D/x.nc|x.csv.
Send a specific code via or simply get one sample by calling getparsiveldata()
Send a specific code or simply get one sample by calling ``getparsiveldata()
sample=> Starts sampling the parsivel for a certain amount of time (default 15 minutes) at a certain frequency (default 10 sec)pollcode=> Sends a single code to the parsivel, which reports the measurement of that code. See parsivel manual for codesgetparsiveldata=> Polls the parsivel with CS/PA and save the return values to self.buffer / self.data (the first being a byte string the latter being a dict which contains the answer per code)help=> Returns the parsivel help (which lists CS/X commands that could be issued to the parsivel. See parsivel manual for more informationgetconfig=> Returns the current config of the parsivel. See parsivel manual for more informationwrite2file=> shorthand for callingwrite2nc/write2asdofilewhere each writes out data to a dailyfile in the corresponding format- Various helper functions, such as
poll,clearbuffer,cleardata,clear,velocity_classes,diameter_classes,_setupncfile - More methods/attrs => See pyserial documentation as the class parsivel class inherits all attrs/methods
-
settime=> sets the parsivel time to the computer time in UTC, no args -
gettime=> gets the parsivel time, no args -
setdate=> sets the parsivel time to the computer date in UTC, no args -
getdate=> gets the parsivel time, no args -
setdatetime=> sets the parsivel date and time to the computer date and time in UTC, no args -
getdatetime=> gets the parsivel date and time -
setrtc=> sets the parsivel rtc time to the computer datetime in UTC, no args -
getrtc=> gets the parsivel rtc time, no args
setstationname=> Sets the string passed as argument as station namegetstationname=> Gets the currently saved station name from the parsivel, no args
setstationname=> Sets the string passed as argument as station namegetstationname=> Gets the currently saved station name from the parsivel, no args
- Writeoutfreq should allow for writing out a new record only every x seconds but due the shape missmatch to the netCDf this is not working as intended (yet)
- Due to the timing of processing from polling to actual response the interval is often 1-2 seconds longer than the requested frequency. For anaylysis, this should not make a large difference
The Parsivel is a disdrometer, measuring primarily the size / fall velocity of particles falling through a laser measurement path. You can find more information here The device is usually sampled via RS-485 2W, usually via a data logger or via ASDO (Windows programm). Alternatively, here a linux system was equipped with a moxa serial to usb converter (which by default resides at /dev/ttyUSB0).
Hardware:
- Either a direct serial RS-485 2W connection on the computer or a converter that is available to pyserial
- Power for the Parsivel itself
Software:
- Python: netCDF4, pyserial
- (Ensure converter is set to RS-485 2W, e.g.
setserial /dev/ttyUSB0 port 1 - If you are using a moxa converter on linux, check out their repo
- Simply run file, either via
python3 parsivel2file.pyor change permissions (chmod u+x parsivel2file.py) and run directly./parsivel2file.py