elv is the elevation angle calculated from the lag zero phase of the ACF
elv_high is the elevation angle calculated from the fitted phase (cf. FITACF 2.5 elv)
elv_low is the least square error
FITACF 3.0's appropriation of the elv_high and elv_low fields to store other information is misleading and poorly documented.
Suggested Solution
Add some new fields to the FITACF file format standard so that the elevation angle parameters from FITACF 3.0 are appropriately described. Avoid modifying the definitions of fields used by FITACF 2.5.
Example field definitions:
elv: the elevation angle that is recommended for scientific use
FITACF 2.5: determined from the fitted phase (the only available option)
FITACF 3.0: determined from the lag zero phase
elv_fitted: elevation angle determined from the fitted phase (FITACF 3.0 only)
elv_error: least square elevation angle error (FITACF 3.0 only)
elv_low and elv_high (FITACF 2.5 only)
These errors are often meaningless due to phase flipping and they are rarely used for science. This is why they were removed from FITACF 3.0.
Submitter Name and Institution
Name: Emma Bland Institution: The University Centre in Svalbard Preferred contact method: email or github
Issue Type
* Standard Infringement
Description of Issue
FITACF 2.5 and FITACF 3.0 produce slightly different outputs for the elevation angle and its errors:
FITACF 2.5 (documented here)
elvis the elevation angle calculated from the fitted phaseelv_highis the upper estimate of the elevation angleelv_lowis the lower estimate of the elevation angleFITACF 3.0 (documented here)
elvis the elevation angle calculated from the lag zero phase of the ACFelv_highis the elevation angle calculated from the fitted phase (cf. FITACF 2.5elv)elv_lowis the least square errorFITACF 3.0's appropriation of the
elv_highandelv_lowfields to store other information is misleading and poorly documented.Suggested Solution
Add some new fields to the FITACF file format standard so that the elevation angle parameters from FITACF 3.0 are appropriately described. Avoid modifying the definitions of fields used by FITACF 2.5.
Example field definitions:
elv: the elevation angle that is recommended for scientific useelv_fitted: elevation angle determined from the fitted phase (FITACF 3.0 only)elv_error: least square elevation angle error (FITACF 3.0 only)elv_lowandelv_high(FITACF 2.5 only) These errors are often meaningless due to phase flipping and they are rarely used for science. This is why they were removed from FITACF 3.0.