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Quality of data is the most important factor.

Posted: Mon 03 Apr 2023 10:18 am
by RayProudfoot
Being a former programmer my primary target when keeping weather records is the accuracy of the data. Whilst I may not have the most compelling website I pride myself on the quality of the data it shows. I consider that to be the most important factor as visitors may distrust any new record if they see what are clearly erroneous records.

When I visit some other sites running Cumulus / CumulusMX I am disappointed to see 'records' that are clearly impossible. Why don't the owners correct them? The 'all-time record' LED flashes on both my website and Cumulus when one is broken and on days when it's highly suspicious I investigate the same day and correct the data where necessary asap.

Do you do the same?

Whilst I don't have the appetite to develop my website I do import my dayfile.txt file into a Microsoft Access database where I interrogate and display the data. The image below is the result. Over 5,000 records imported and processed in less than 5 seconds on a Windows 10 laptop. That database with all the SQL code and queries was designed and written over 10 years ago and still works well.

Do any of you do anything similar?
CheadleHulmeWeatherData.jpg

Re: Quality of data is the most important factor.

Posted: Sun 09 Apr 2023 6:19 pm
by davepaterson
It is also very important to know that the data being displayed is correct within reasonable tolerances. My first trip into the UV and Solar readings was with a Aercus WS3085 but got 2000+ W/m2 and UV of 15 (that got altered and eventually got my money back) but bought their Weather Ranger which would give solar readings at 15:00 the same if not higher than 12:00. Now gone for Ecowitt with the HP2552. but how do I find out if my new reading are there or there abouts. There is no reliable WU sites close to me, Ian at Stewarton with the HP2551 is about 20 mile away and someone in Carluke with a HP2553 is about 7 miles away so I can't judge the readings against mine (if they are correct). The theoretical value is mentioned on some posts, so what is it and how is it and solar checked (Idiots Guide) please. No rush as the rain clouds have gathering

Dave

Re: Quality of data is the most important factor.

Posted: Sun 09 Apr 2023 6:35 pm
by RayProudfoot
Dave, I have no experience with solar or UV readings. Sorry. Maybe someone else can assist.

Re: Quality of data is the most important factor.

Posted: Sun 09 Apr 2023 6:44 pm
by davepaterson
Thanks Ray, Simle is only Simple when you know how.

Re: Quality of data is the most important factor.

Posted: Sat 20 Apr 2024 10:16 am
by philpugh
Dave, I have 3 Ecowitt station (WH65, WS68 and GW2001) and whilst the UV / Solar readings are in reasonable agreement I would not call them accurate. The problem with these 'inexpensive' weatherstations is that they measure the light level only and derive the W/sqM and UVI from generic formulas. What you can do is wait for a really clear day with bright sunlight and check on Cumulus how the reported power stands up to the maximux theoretical - it should be close but always below this - certainly in the UK we generally have significant amouts of water vapour in the atmosphere which affects the actual solar power received. Anyway you could then use the multiplier function provided in Cumulus to 'correct' the solar power figure. But you will find on bright cloudy days the 'measured' power may exceed the maximum theoretical because of light reflection from the clouds. As for the UVI a check on the Met Office (or similar) website should give you a reasonably accurate UVI figure for your area and you can apply a similar correction factor to your measured value. However the figures will never really be accurate.