Air Mass Average - AM-AVG?

[James DeYoung]

When I stack a few images I get a data record called JD-AVG which is the average JD corrected using half the exposure time to the mid-point JD of all the images. It would be useful to have say an equivalent record called perhaps, AM-AVG, that is generated by reading and averaging the air mass values from the individual stacked images. In my observing system the air mass values are written to each image. I believe the air mass values in the individual file fits headers from the observing system are for the start of the observation... so some interpolation might be required to get an AM-AVG value at the equivalent JD mid-point.

Also the JD-AVG value is written in scientific notation and it would be useful to have it written in the same floating point format as the original JD values to make it easier the visual comparison of the text values.

Thanks very much

[han.k]

AM-AVG, that is an interesting idea. I will have a look into it. Yes all floats are written in scientific notation. In the past this was chosen to have a fixed lengh for the header key word value. I will have look into it as well for some values.

Han

[han.k]

airmass at JD-AVG is probably the best approach.

[han.k]

Using airmass doesn't work correctly if there is an long time span between the frame. I implemented the following:

1) Added average AIRMASS for stacks.
2) Added AIRMASS calculation to batch solve menu.

Since you already have AIRMASS in the header, this should work straight out of the box. Other users can add AIRMASS to the frames using the batch solve menu in the tools menu of the viewer.

I decided to use the keyword AIRMASS. Only the comment mentions average. Something like this:
AIRMASS = 1.2245 / Average relative optical path.

Implemented in Windows development version. Please tell me if this working correctly for you:

http://www.hnsky.org/astap_setup.exe

Han