If you're concerned about the distance to the airport, you can take your console to the airport --- it's battery powered.
In addition to my Vantage, I have a precision barometer that I use for sailing (±0.25 hPa precision). I've calibrated it against the Portland airport, which is very close to sea level, then brought it home, and calibrated my Davis consoles. The onboard barometer of an iPhone is also surprisingly accurate. Use the Starpath app <https://www.starpath.com/marinebarometer/about.htm> to calibrate it near an airport, then bring it home. There are lots of approaches. Best to do all of the above, then triangulate the results. -tk On Mon, Jan 11, 2021 at 12:24 PM Nate Bargmann <[email protected]> wrote: > * On 2021 10 Jan 20:02 -0600, Tom Keffer wrote: > > The note *Derived variables > > < > https://www.davisinstruments.com/product_documents/weather/app_notes/AN_28-derived-weather-variables.pdf > >* > > from > > Davis has a pretty good discussion of this. > > Thanks, Tom. > > I have a Vantage Pro2 and I see this: > > $ sudo wee_device --info > Using configuration file /etc/weewx/weewx.conf > Using Vantage driver version 3.2.1 (weewx.drivers.vantage) > Querying... > Davis Vantage EEPROM settings: > > CONSOLE TYPE: Vantage Pro2 > > CONSOLE FIRMWARE: > Date: Jun 3 2013 > Version: 3.15 > > CONSOLE SETTINGS: > Archive interval: 300 (seconds) > Altitude: 1327 (foot) > Wind cup type: large > Rain bucket type: 0.01 inches > Rain year start: 1 > Onboard time: 2021-01-11 04:37:42 > > CONSOLE DISPLAY UNITS: > Barometer: inHg > Temperature: degree_F > Rain: inch > Wind: mile_per_hour > > CONSOLE STATION INFO: > Latitude (onboard): +39.9 > Longitude (onboard): -96.8 > Use manual or auto DST? AUTO > DST setting: N/A > Use GMT offset or zone code? ZONE_CODE > Time zone code: 6 > GMT offset: N/A > Temperature logging: LAST > Retransmit channel: OFF (0) > > TRANSMITTERS: > Channel Receive Repeater Type > 1 active none iss > 2 active none temp (as extra temperature 1) > 3 active none (N/A) > 4 active none (N/A) > 5 active none (N/A) > 6 active none (N/A) > 7 active none (N/A) > 8 active none (N/A) > > RECEPTION STATS: > Total packets received: 6411 > Total packets missed: 90 > Number of resynchronizations: 0 > Longest good stretch: 751 > Number of CRC errors: 12 > > BAROMETER CALIBRATION DATA: > Current barometer reading: 30.344 inHg > Altitude: 1327 feet > Dew point: 23 F > Virtual temperature: 29 F > Humidity correction factor: 0.7 > Correction ratio: 1.052 > Correction constant: -0.024 inHg > Gain: 0.000 > Offset: -24.000 > > OFFSETS: > Wind direction: +0 deg > Inside Temperature: +0.0 F > Inside Humidity: +0 % > Outside Temperature: +0.0 F > Outside Humidity: +0 % > Extra Temperature 1: +0.0 F > > > In this case, 1327 feet is the height of the console including its > height above ground level which is stated to be 1318 feet by Google > Earth and topographical map estimation. > > The closest airport with a reporting station is about eight miles > east/southeast from here and I have the console set to match its > pressure reading as shown on its NWS page. Its elevation is stated to > be 1283 feet, so 44 feet lower than my console. > > I've never been exactly clear from the Davis documentation just who I > should be doing. My guess is that the 44 feet and eight mile difference > is probably inconsequential on a clear sunny day like this. The > difference likely is greater under more localized conditions such as > when a squall line moves through. > > My goal is to "color" my data as little as possible and my station does > report to CWOP and seems to get satisfactory marks from MADIS. > > - Nate > > -- > > "The optimist proclaims that we live in the best of all > possible worlds. The pessimist fears this is true." > > Web: https://www.n0nb.us > Projects: https://github.com/N0NB > GPG fingerprint: 82D6 4F6B 0E67 CD41 F689 BBA6 FB2C 5130 D55A 8819 > > -- > You received this message because you are subscribed to the Google Groups > "weewx-user" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/weewx-user/20210111202418.nefk6sla3prmrovx%40n0nb.us > . > -- You received this message because you are subscribed to the Google Groups "weewx-user" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/weewx-user/CAPq0zEDmvNtRZ%2BDSeu4A0UrrxQDJt%2B3GPQXmSoP-dWBx_HBDhg%40mail.gmail.com.
