Should `calculate_vp` use use the geo attributes

[bart1]

I noticed this issue causing incorrect vp altitudes. That is meanwhile fixed. However I wondered if calculate_vp should fall back to x$geo$height if x$attributes$where$height is not available. Below you see how the antenna is assumed to be at the ground when no height is present in the attributes. I would see to possible improvements:

• Warn when the height is absent
• Warn when the assumption of height 0 is made
• Use the height from geo when possible

require(getRad)
#> Loading required package: getRad
a<-getRad::get_pvol("fikau", Sys.time()-10000)
a$attributes$where$height
#> [1] 463
a$geo$height
#> [1] 463
plot(bioRad::calculate_vp(a), main="original")
#> Running vol2birdSetUp
#> Warning: radial velocities will be dealiased...

b<-a; b$geo$height<-NULL
plot(bioRad::calculate_vp(b), main="no geo height")
#> Running vol2birdSetUp
#> Warning: radial velocities will be dealiased...

b<-a; b$attributes$where$height<-NULL
plot(bioRad::calculate_vp(b), main="no attribute height")
#> Running vol2birdSetUp
#> Warning: radial velocities will be dealiased...

^{Created on 2025-10-13 with reprex v2.1.1}

[adokter]

The radar height is read from the /where/height attribute group of the polar volume

bioRad/R/read_pvolfile.R

Line 180 in d8542ae

vol.height <- c(attribs.where$height)

It is then written to both x$geo$height and x$attributes$where$height, so they should always be copies of each other

bioRad/R/read_pvolfile.R

Line 217 in d8542ae

geo <- list(lat = vol.lat, lon = vol.lon, height = vol.height)

bioRad/R/read_pvolfile.R

Line 238 in d8542ae

attribs.where$height <- vol.height

I believe we did this to be able to copy easily the x$geo information to scans and parameters. Have you seen examples where they are different or where one of the two is missing?

[bart1]

I encountered this when I was constructing a pvol "manually" in R from separate scans see aloftdata/getRad#139. So most users won't encounter this, I just thought a warning would be useful.

[bart1]

I'll make a pull request with a warning