Gate altitude calculation

[saranya00-s]

Is the function pyart.core.Radar.get_gate_lat_lon_alt is returning earth curvature corrected heights? Please confirm.

[zssherman]

@saranya00-s that function returns the current lat lon and alt from a radar sweep. But those variables are calculated from:

pyart/pyart/core/transforms.py

Line 424 in 14f625a

def geographic_to_cartesian_aeqd(lon, lat, lon_0, lat_0, R=6370997.0):

Which does calculate the arc length along Earth's curvature.

[saranya00-s]

I think this function "geographic_to_cartesian_aeqd(lon, lat, lon_0, lat_0, R=6370997.0)" returns x,y,z values. But here we need a antenna to geographic transformation. Then which coordinate transformation function is used in pyart.core.Radar.get_gate_lat_lon_alt ?

[zssherman]

Oops yeah correct, mistake on my part, I meant to share:

pyart/pyart/core/transforms.py

Line 599 in 14f625a

def cartesian_to_geographic_aeqd(x, y, lon_0, lat_0, R=6370997.0):

[zssherman]

the x, y, z that get placed into that for retrieving the lat lon etc is from this:

pyart/pyart/core/transforms.py

Line 108 in 14f625a

def antenna_vectors_to_cartesian(ranges, azimuths, elevations, edges=False):

[zssherman]

So essentially ranges, elevations and azimuths into antenna_vectors_to_cartesian, then x, y, into cartesian_to_geographic_aeqd. Then the function for 'get' you shared above retrieve those lat lons for a specific sweep.

[saranya00-s]

Ok. Now it's clear. Thank you

…

On Sat, 28 Sep, 2024, 7:47 pm Zach Sherman, ***@***.***> wrote: So essentially ranges, elevations and azimuths into antenna_vectors_to_cartesian, then x, y, into cartesian_to_geographic_aeqd. Then the function for 'get' you shared above retrieve those lat lons for a specific sweep. — Reply to this email directly, view it on GitHub <#1657 (reply in thread)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/BKGJ6JKXBQL4RZYPSY7XADDZY2277AVCNFSM6AAAAABO6N3Y7SVHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTANZYGM4TQNY> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[zssherman]

No problem!