Proposition to add new properties to ObservingConditions

[ppp-one]

Hi — we use ASCOM extensively at our multiple faciliites, and with more robotic facilities coming online, I’d suggest adding Relative Sky Temperature (SkyTemperature - Temperature, RelativeSkyTemp) and Precipitable Water Vapor (PWV) to ObservingConditions.

These parameters are important for automated safety decisions as well as post-processing of data.

For Relative Sky Temperature, it would be helpful if it were provided as a single queriable value, allowing users to assign safety limits directly without needing to calculate it themselves. For PWV, low-cost sensors are becoming more accessible, and the data can similarly be used for safety triggers.

I look forward to your thoughts.

Thanks,
Peter

[Peter-Simpson]

Hi Peter,

Thanks for making your suggestions!

We have done our best in the ObsCon interface only to include discrete independent variables, the related Humidity and DewPoint properties being the only exception as far as I'm aware, so I suspect there would be concerns about including the simply derived RST value in the interface specification.

PWV on the other hand looks like it would be a good addition to the interface. We intentionally don't revise interfaces frequently in order to provide stability for client and driver / Alpaca device authors, and we revised all interfaces in October of last year, so it is likely to be some time before the next interface change.

One way forward would be to use the Action / SupportedActions mechanic, which enables you to add non-standard functionality to a standard ASCOM interface. This would enable you to create your own PWV driver and return information to your client quickly without waiting for a formal interface change.

Best wishes, Peter