Hi Gary,  I've spent some time looking at the log files and focusing on the 
windgust, still unresolved unfortunately.  

I’m using the interceptor driver,  I looked at the comments in the 
interceptor driver code which says 

"*The gust measure has resolution of 1.1 m/s (2.46 mph) - one revolution of 
the anemometer."*  

However the lowest gust value in the LOOP logs is “0.683510010315”.  There 
must be a units problem here,  I understand that “0.683510010315” 
usunits=1=mph, displayed in the each log record, and will convert to 1.1 
km/h,  but the console shows 4 km/h,  so I’m assuming that 1.1 is m/s which 
converts to 3.96 km/h, very confusing,  but I can get the figures to match 
even if they don’t make sense to me. Is there a simple explanation about 
these figures?

 

I notice that the LOOP & debug data for windgust is consistently the same, 
however debug data does not show the REC: records,  these are only shown 
from the weewx direct logs. I'm unsure if the interceptor driver is sending 
the REC: records,  do you know? 

I assume it is as weewx.conf says 

*“[StdArchive]*

*….*

*# Set the following to "software" to force software record generation.*

*    record_generation = hardware”*


On Wednesday, 11 March 2020 22:10:40 UTC, Simon Davies wrote:
>
> Hi Gary,
>
> From my previous table "DB" showed the windGust value.
>
> As requested,  I've taken readings from the weewx direct LOOP/REC data,  
> debug data,  extract from the DB and I've taken a couple of screenshots 
> from the console.  
> Time period would be best to take from 21:03 for  approximately 15 
> minutes,  although the logs cover a larger period.  I've attached 5 files 
> with this information.  I hope they contain the information you have 
> requested.
>
> I've not checked all of the values myself,  I'll will do after posting 
> here.
>
> loop_hilo is set to True.
>
> Many Thanks Simon
>
> On Wednesday, March 11, 2020 at 4:11:45 AM UTC, gjr80 wrote:
>>
>> Hi Simon,
>>
>> I tried setting the debug level to 1 and viewed the syslog.  The units 
>>> displayed in the log are usunits=16 (which I assume is meters per second?). 
>>>
>>
>> The usUnits decodes are 1 (or 0x01) is US (aka US customary) and uses 
>> miles per hour for wind speeds, 16 (or 0x10) is Metric with wind speeds in 
>> km per hour and 17 (or 0x11) is known as MetricWX with wind speeds in 
>> metres per second.
>>  
>>
>>> I could not understand how these values were used to be stored in the 
>>> archive database.  
>>>
>>
>> A little background on how units are used within WeeWX. First up the 
>> database, in weewx.conf under [StdConvert] you have a setting 
>> target_unit that will either be US, METRIC or METRICWX. This sets the 
>> database unit system used throughout the database. The default is US. Some 
>> folks insist on having target_unit set to the units they use natively, 
>> there really is little value in doing this unless you have specific 
>> requirements as WeeWX automatically converts to/from the units required (in 
>> fact I have seen it cause issues variously where database units are used 
>> (for example specifying QC limits without units), folks forget their 
>> database units are different to the normal and they can get unexpected 
>> results). Data coming from drivers, whether they be loop packets or archive 
>> records can be in any of the three unit systems, WeeWX automatically 
>> converts any data being saved to database to the target_unit unit 
>> system. Likewise any archive records or loop packets being processed 
>> elsewhere by WeeWX could be in any of the three unit systems. Data being 
>> output in a Cheetah report or plotted by the image generator is 
>> automatically converted to the units specified by the tag, skin.conf or 
>> weewx.conf or the defaults as applicable. Bottom line is when analysing 
>> WeeWX data never assume any units, always check the usUnits value.
>>  
>>
>>> See the table below,  for example 1.1 mps  becomes 1.36 mph.  it should 
>>> be 2.46 mph using my calculations.  Do you have any ideas why the archive 
>>> DB has this value?
>>>
>>>  
>>>
>>>  
>>>
>>> *time*
>>>
>>> *debug data wind gust (mps)*
>>>
>>> *debug data usunits*
>>>
>>> *console minutes*
>>>
>>> *console wind gust km/h*
>>>
>>> *DB (mph)*
>>>
>>> Mar
>>>
>>> 8
>>>
>>> 22:40:57
>>>
>>> 1.1,
>>>
>>> 16
>>>
>>> 40
>>>
>>> 4
>>>
>>> 1.36702
>>>
>>> Mar
>>>
>>> 8
>>>
>>> 22:42:49
>>>
>>> 0.0,
>>>
>>> 16
>>>
>>> 42
>>>
>>> 0
>>>
>>> 0.68351
>>>
>>> Mar
>>>
>>> 8
>>>
>>> 22:44:57
>>>
>>> 1.1,
>>>
>>> 16
>>>
>>> 44
>>>
>>> 4
>>>
>>> 2.05053
>>>
>>> As mentioned above you usUnits=16 data will be km/hr rather than m/s. 
>> That still doesn't help things tally. So what is 'DB', is that windSpeed 
>> or windGust?
>>
>> Appreciate the table may make things easy to read but perhaps it might 
>> help more if you provide the actual loop/archive record output when WeeWX 
>> is run directly, a copy of the log (with debug set) over the same period 
>> and a query from the database again covering the same period and your 
>> recorded observations of the console gain over the same period.
>>
>> So when there is some wind around let's run WeeWX directly for about 5 
>> minutes. At the same time WeeWX is running directly note your wind speed 
>> values on the station display. Capture the console output (LOOP: and REC: 
>> data) for the entire period. Take a log extract that covers the entire 
>> period that WeeWX was run directly.
>>
>> Now query the database after finishing the direct WeeWX run. Am assuming 
>> you are using SQLite as your DBMS. Note you may need to install the sqlite3 
>> application using sudo apt-get install sqlite3 if not already installed. 
>> Also assuming your database is named weewx.sdb and it is located in 
>> /home/weewx/archive (it may be located in /var/lib/weewx depending on 
>> your WeeWX install method - adjust following command as necessary):
>>
>> $ sqlite3 /home/weewx/archive/weewx.sdb
>> sqlite> .headers on
>> sqlite> SELECT datetime,datetime(dateTime,'unixepoch','localtime'),
>> usUnits,windSpeed,windGust FROM archive ORDER BY dateTime DESC LIMIT 20;
>>
>> that will display the timestamp, human readable date-time, usUnits, 
>> windSpeed and windGust values for the last 20 minutes (use .quit to exit 
>> sqlite3). If run within 15 minutes of completing your direct run we should 
>> have some overlapping data to compare from (1) the loop packets and archive 
>> records seen by WeeWX (2) the raw data seen by the SDR driver (3) your 
>> visual observations of the station display and (4) the database. Post these 
>> four pieces of data.
>>
>> One final question, is your loop_hilo setting under [StdArchive] in 
>> weewx.conf set to True or something else?
>> Gary
>>
>

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