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onepk

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  1. One suggestion was this utility, but it requires (gives an error message when trying to run the .exe file) .Net Framework 4 and I cannot run that so cannot tell if the utility is useful or not. http://www.ruysfamily.com/WLKReaderWriter/WLKAppDownload.html
  2. Does anyone know of a way of editing the data files created by the Weatherlink software (ie the *.wlk files). The Weatherlink s/w allows editing of records one at a time, but after some of my detectors failed it was a while before new ones were installed and so the database files have several thousand records which need corrected (ie data value set to zero or non-valid value). I'm looking for a means to do a global edit in one or at most a few steps. Thanks
  3. It seems my VP2 kit has suffered from a nearby lightning strike - after the strike no data were received for the best part of a day (ISS test LED dead), then all sensors spontaneously returned unaided apart from wind direction and sun sensor. It seemed like a catastrophic loss of power, even from the battery (6 months old), and the solar cell took time to recharge - is this a feasible explanation? After the self-recovery I fitted a new battery to the ISS and that seemed to make communication more robust. I'm now assuming the wind/sun transmission electronics are beyond hope (have tried different station IDs, rebooting etc etc). Has anyone else had this experience? Are there any suggested ways of mitigating against this vulnerability? The equipment does tend to be found in exposed places and having the possibility of a serious and expensive repair after such events (even if it happens in only a small percentage of storms) seems an unattractive proposition.
  4. Just a quick update in case anyone is still awake! Adrian Hudson (http://www.willandweather.org.uk/index.php) was kind enough to confirm that he sees the same effect with his sun sensor and said he thought it was a well-known effect caused by the sun's illumination of clouds. I am attempting to track down any academic study which explains or models the physics of the effect in detail (replies awaited from Davis support and the Met Office). In the meantime I have gained access to some pyranometer data kept by the BADC through which I hope at least to be able to characterize the effect so that others don't have to go through the "is it me?, is it my equipment? is it the site?" process I did. I might even be able, with evidence, to inform "support" at Davis that reflections are not the only possible answer or cause! Cheers Onepk PS. it appears the Davis sun sensor MIGHT indeed archive average values, but only those taken on the minute time stamp. For a one minute archive interval, you still get the average.... but only of one reading!
  5. Thanks again for your thoughts Stormmad26. What the data logger does in terms of averaging (rather than the timing of the interval) is given in this extract from the WeatherLink help file. "What we call "current solar radiation" is technically known as Global Solar Radiation, a measure of the intensity of the sun’s radiation reaching a horizontal surface. This irradiance includes both the direct component from the sun and the reflected component from the rest of the sky. The solar radiation reading gives a measure of the amount of solar radiation hitting the solar radiation sensor at any given time, expressed in Watts per square meter (W/m2). The value logged by WeatherLink is the average solar radiation measured over the archive interval." It seems to be different for temperature in the sense that averaging is optional:- "The Vantage Vue/Vantage Pro/Vantage Pro2 either samples the temperature at the end of the archive period and writes it to the data logger, or samples the temperature throughout the archive period and calculates an average value at the end of the period. Note: Temperature averaging is available as an option only for Vantage Vue, Vantage Pro consoles with firmware is dated 7/18/2002 or later. " On the latest Pro2 software, the temperature averaging option is settable under "Set temperature and humidity calibration" and the temperature data to be averaged is sampled every 5 secs for any archive interval <= 10 mins. This still leaves open the question of when an archive time interval starts. I've asked Davis to advise on this - hopefully they're not on a 4-day weekend! Any ideas on where I might find a pundit to answer the "high cirrus" question? I could try the Met Office I suppose, they usually (ie are presumably legally obligated to) reply to all dumb questions! Cheers Onepk
  6. Thanks for the comments reef and Stormmad26. I note from the trouble-shooting section of the Vantage console manual that they suggest that unusually "high" solar sensor readings could be caused by the presence of high, thin cirrus. As a general meteorological question, any idea of the physical mechanism behind such a phenomenon? One supplementary question I had, specific to the Vantage, concerns the time-stamp in the data records. Each stored data value is supposed to be the average readout over the requested interval (1 min.... 30 mins). The answer may be buried in the documentation - apologies if so - but does anyone know whether, for example, a data record time-stamped 08:01 with a 1 min archive interval will be the averaged data from 08:00:00 --> 08:01:00 08:00:30 --> 08:01:30 or 08:01:00 --> 08:02:00 Comparing the data displayed on the console with the archived data, I have my doubts that it's any of them! Also what is the sensor readout frequency (ie readings per time interval not electromagnetic!) - does it vary from sensor to sensor? Just wondering what it means when the manual says the console displays the "current" value. Cheers
  7. Just an update and to add at least one reply in case anyone is still looking! I got a 'reply' from support@Davis only to say it must be caused by a reflection or reflections from something. Haven't time to list the reasons why this seems unlikely to say the least. The folk at Prodata Weather Systems, from whom the kit was purchased, at least took time to listen and to look at the data in detail, but had no suggestions apart from possible reflections or connection/signal transmission problems. Even on that basis they did concede that it was strange the phenomenon only occurred on cloudy days. They also pointed out that day-to-day comparisons may not be legitimate because of atmospheric clarity changes - a cloudless sky does not necessarily mean a very transparent sky . That is true, but I have examples where internally the day's irradiance envelope is quite obvious (from lengthy spells of unobstructed sun) and can easily be interpolated, yet between episodes of cloudiness during that same day, the irradiance still goes well above that day's envelope, let alone above the envelope of adjacent cloudless days. I can't help but feel I'm missing something obvious here - still nobody any ideas? Can anyone out there with a Davis sun sensor at least confirm that they do NOT ever see the same effect? Thanks
  8. Hello, I've had a Vantage Pro2 system for a couple of months now and I'm curious about some data from the sun sensor. On partially cloudy days it often (actually it always at some point) shows values greater than are achieved at the same time on cloudless days (see attached plot, 1 min interval data from 26 & 28 May*). Is this caused by reflection from clouds being "brighter" as seen by the sensor than the patch of sky they fill or something else, instrumental or otherwise? Also does anyone know of a source of quantitative info on the sun sensor (spectral response etc.)? I've asked Davis but not had any reply so far. Thanks for any ideas. * the decline at around 12:20 is an artificially induced shadow.
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