About our meteorological Station

Street Address: 4ta. Calle Oriente # 14, Antigua Guatemala.

Geographical location:
14°33’30” N
90°43’48” W
Elevation: 1553.9 m

Relative elevation:
About 5 m above ground, on height with the roof top. This was chosen because the terrain and buildings would shield for Wind and Rain Data if mounted anything lower. I have read somewhere that a reputable station should be mounted 2 m above ground in open terrain, in a well ventilated box that should be painted bright white. The white paint we could do.

Calibration:
The Temperature and Humidity Sensor is one integrated professional unit, and should be very accurate. It is mounted in a separate sensor tube, close to the air and away from dust and insects.

The Anemometer is an in-house construction, (Not without pride since it is quite sensitive) with deep roots in something that once was a computer case fan. It is roughly calibrated, in lack of a reference. Someone would please borrow me his/her Wind tunnel, which you US residents certainly have in every household ;) ?

The rain counter is a classic tipping-bucket style sensor. It was born as a semi-professional unit that was modified and recalibrated. Being a semi-pro unit, it was horribly out of calibration, by the way. It came designed with a resolution of 1 mm rain, and in the future maybe we can provide 0.1 mm resolution, if a sponsor for something better shows up.

Data collection:
Is done with a basic stamp module. Specially the Temp/Rh sensor coding would have been a pain to do without the help of code from: http://www.emesys.com/BS2index.htm#webRing, so Kudos goes there. A lot of other good ideas were derived from Emesys’ pages. This is an interesting site!

Data I/O on the server:
Done with homegrown VB .net code. The formatted data coming from the serial port from the basic stamp is logged to a CSV file every 5 minutes on our server. All other presentation, that is: Graphing, averaging, etc. is done with MRTG, Tobias Oetiker’s excellent Multi Router traffic Grapher, written in Perl. – Which has many other uses besides router traffic stats, as this application demonstrates.

Scope of the station:
To my best knowledge, there are no other meteorological stations in Antigua Guatemala at the time of this writing. The project was done in a 4 month period on a zero-budget. 4 months is a long time, but it was done in idle hours, or off-duty when there was nothing else to attend. I took it as a “refresher” for knowledge in electronics, mechanics, system integration, low and high level programming. These are the skills a project like a weather station that presents graphs on weather data comes down to.

Future: I would like to include barometric pressure and solar radiation data. That has to wait until a sponsor for the hardware shows up. Although this is/was a zero-budget project, it HAS cost money. For the Basic Stamp Module, for the rain counter, for the Temp/Rh sensor, and small parts. A rough total of $220.- The “commercially interesting” data are historical backlogs of raw data, presented in CSV format. Those we will collect over time, but will only make them available for a fee. Maybe one day the $220 are recovered via contributions from parties interested in the raw data. Until then, access to raw data is fee based.