Holden

Unit Conversions

• mm values are converted at 25.4mm x reported in (inches) value
• kph values are converted at 1.609344 x reported mph value

Columns

Date Time

• Value is saved to the database from [observation_time_rfc822] API field
• Value is saved to the database with the minute and second elements set to zero
• This data is used for all dynamic calculations
• Note that the data collection is triggered by running a “cron job” on the server.  This is configured to run twice per hour – at 15 mins and 45 mins past the hour. 15 mins past the hour is recommended by the Davis guidelines and is then saved in the database as 00 mins. The second cron job is in place so that if the first cron job fails or didn’t run, then the second cron job at 45 mins after the hour will attempt to collect the data for that hour. The script is configured that at 45 mins past the hour, it checks if there is data from the 15 mins past the hour cron job. If yes, it will not add another data row for that hour in the database. If the first cron job failed, and this second cron job collects data at 45 mins past the hour this will be saved to the database as 00 mins in order to have consistency in time displayed across rows. If for any reason both cron jobs fail, the table will add a row with no data.

Ta – current air temperature

• Value is saved to the database from [temp_c] API field

24hr Ta Max – Max temperature since reset hour

• Value is dynamically calculated by comparing temperatures from all rows between the reset hour row and the current row
• If the current row’s hour value is larger than the reset hour value, the range of temperatures to compare will be from the current day’s reset hour to the current row’s hour
• If the current row’s hour value is less than or equal to the reset hour value, the range of temperatures to compare will be from yesterday’s reset hour to the current row’s hour

24hr Ta Min – Min temperature since reset hour

• Value is dynamically calculated by comparing temperatures from all rows between the reset hour row and the current row
• If the current row’s hour value is larger than the reset hour value, the range of temperatures to compare will be from the current day’s reset hour to the current row’s hour
• If the current row’s hour value is less than or equal to the reset hour value, the range of temperatures to compare will be from yesterday’s reset hour to the current row’s hour

RH – current relative humidity

• Value is saved to the database from [relative_humidity] API field

HS – current total snow on the ground

• This field is currently not available

HS Sig Qual – sensor value

• This field is currently not available

Precip Gauge Total – cumulative total of mm of precipitation in gauge since reset (done at station)

• Value is saved to the database from [rain_year_in] API field
• Before saving to the database, the value is converted from “in” to “mm”

Hour precip mm – mm of precipitation recorded in the past hour

• Value is dynamically calculated by comparing “Precip Gauge Total” value of the last hour and the current hour
• If both the last and current hour of “Precip Gauge Total” field are not defined, this field will also show value as not defined
• If only the last hour of “Precip Gauge Total” field is not defined, the value of this field will be equal to this hour’s “Precip Gauge Total” field
• If both the last and the current hour of “Precip Gauge Total” field are defined, and the past hour’s value is greater than the current hour’s value – that is recognized as the hour period in which a reset occurred, so the value of this field will be equal to the current row’s “Precip Gauge Total” field
• If both the last and the current hour of “Precip Gauge Total” field are defined, and the past hour’s value is less than or equal to current hour’s value – the value of this field will be calculated by this formula: ( this_hour_precip – last_hour_precip )
• As “Precip Gauge Total” value is already converted to “mm” unit, this value is also represented in “mm” units

24h Sum Precip – running total of mm of precipitation for the past 24 hours.

• Value is dynamically calculated by comparing all rows of “Precip Gauge Total” field for the past 24 hours relative to this row’s hour
• Comparison of values is done in exactly the same way as above ( Hour precip ) field. With the only difference that comparison is done for the past 24 hours instead of only past hour
• As “Precip Gauge Total” value is already converted to “mm” unit, this value is also represented in “mm” units

72h Sum Precip – running total of mm of precipitation for the past 72 hours.

• Value is dynamically calculated by comparing all rows of “Precip Gauge Total” field for the past 72 hours relative to this row’s hour
• Comparison of values is done in exactly the same way as above ( Hour precip ) field. With the only difference that comparison is done for the past 72 hours instead of only past hour
• As “Precip Gauge Total” value is already converted to “mm” unit, this value is also represented in “mm” units

28day Sum Precip – running total of mm of precipitation for the past 672 hours.

• Value is dynamically calculated by comparing all rows of “Precip Gauge Total” field for the past 672 hours relative to this row’s hour
• Comparison of values is done in exactly the same way as above ( Hour precip ) field. With the only difference that comparison is done for the past 672 hours instead of only past hour
• As “Precip Gauge Total” value is already converted to “mm” unit, this value is also represented in “mm” units

Wind Speed kph – current 2 min average in kph wind speed as reported by station

• Value is saved to database from [wind_mph] API field
• Before saving to database, value is converted from “mph” to “kph” units

Wind Dir Deg – direction of current wind as reported by station

• Value is saved to database from [wind_degrees] API field

Vel 3sec Gust – speed of highest gust in kph during the past hour as reported by station

• Value is saved to database from [wind_ten_min_gust_mph] API field
• Before saving to database, value is converted from “mph” to “kph” units

Dir 3sec Gust – direction of gust

• This field is currently not available

Time 3sec Gust – time of gust

• This field is currently not available

Batt Volts – station battery level

• This field is currently not available

Logger Intrnl Temp – internal temperature of the station

• This field is currently not available