They may be reporting every 2.5 secs, but I believe the rain rate is only 
updated every 20 seconds.  To make matters worse, looking at the davis 
comms protocol it is not clear what they actually output - as rainrate is 
defined as clicks per hour!  Loop2 packets include 15 minute rainfall, hour 
rainfall, dialy rainfall - all looks quite complex, and that is just for 
davis stations!!

Have fun, I'm not commenting further.



On Friday, 3 August 2018 08:24:39 UTC+3, Praveen Chandrasekaran wrote:
>
> Davis vantage stations report every 2.5 seconds I believe and the rainfall 
> rate is also calculated so. Atleast for stations reporting in rapidfire 
> mode I believe the same value that gets displayed on the console can be 
> sent to WU also?
>
> On Fri, 3 Aug 2018 at 10:43, Andrew Milner <[email protected] 
> <javascript:>> wrote:
>
>> Rainfall as a rate is some amount of rain per some defined time period.  
>> OK, we can measure the rain quantity - but what is the time period over 
>> which the rain has fallen??  Instantaneous would be a time period of zero 
>> so would result in zero!!  So do we use 1 second, 5 seconds, 10 seconds, 1 
>> minute, 5 minutes, 10 minutes, or one hour as the time period??  If you use 
>> say 10 seconds then I suppose you need to report every 10 seconds (colossal 
>> overheads at WU if every staion reported every 10 seconds).  However, if 
>> you report every 10 minutes but have a rainrate over a 10 second period, 
>> what do you report to WU as the rainrate for the 10 minute period?  You 
>> cannot just upload the 10 second rate as over the 10 minute period it would 
>> not be correct!!  So, you are almost forced into the current WU arrangement 
>> as possibly being the best compromise situation...…..
>>
>> My view anyway …….
>>
>>
>>
>> On Friday, 3 August 2018 07:17:13 UTC+3, Praveen Chandrasekaran wrote:
>>>
>>> Hi,
>>>
>>> I am discussing with Tim Roche of WU over trello on rainfall rate in WU. 
>>> Ideally I would have liked if WU reported instantaneous rainfall rate than 
>>> the accumulated rainfall in last 60 minutes. Here is what Tim Roche replied 
>>> on trello:
>>>
>>> Rainfall rate and daily precip are inputs to the PWS data. if they are 
>>> sent we use them.
>>>
>>> http://wiki.wunderground.com/index.php/PWS_-_Upload_Protocol
>>>
>>>
>>> I have again replied to him with the below:
>>>
>>>
>>> The PWS upload protocol only has below:
>>>
>>> rainin - [rain inches over the past hour)] -- the accumulated rainfall 
>>> in the past 60 min
>>>
>>> This is not instantaneous rainfall rate. This is interpreted as the 
>>> rainfall accumulated in past 60 mins and sent by weewx to WU. Some details 
>>> on same in below thread too:
>>> https://www.wxforum.net/index.php?topic=9155.0
>>>
>>>
>>> I was just wondering if weewx can be hacked/modified to send 
>>> instantaenous rainfall rates instead of SQLSUM. If so where should I make 
>>> the changes? (restful.py)
>>>
>>>
>>> Maybe others here can also chime in on the trello board so that we can 
>>> sort out this issue. Reporting rainfall over last hour as rainfall rate 
>>> doesn't make sense. Particularly in tropical areas where we may get short 5 
>>> minutes bursts of rains.
>>>
>>>
>>> Trello board link:
>>>
>>>
>>> https://trello.com/c/roVxyTpV/29-submit-bug-reports-june-july-2018
>>>
>>>
>>> Regards,
>>>
>>> Praveen
>>>
>>>
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