Heading angle in offset tracking


I am using offset tracking to calculate the AZO and trying to change the coordinates from azimuth-range to N-E, but when I open the velocity table as follows:

I am not sure that if the definition of heading is same as I knew.
I thought the heading angle is the angle between the range direction and E-axis, but the heading angles of those points in the figure above are quite different.
Am I misunderstanding something?

From my understanding it is from North, in clockwise order

You can also use the range and azimuth shift and use the platformHeading of the sensor in the metadata

S1A_IW_GRDH … -> Metadata -> Original_Product_Metadata -> annotation -> s1a_iw_grd… -> product -> generalAnnotation -> productInformation -> platformHeading

Thanks for your reply! But I am not sure if the heading means the direction of offset?

It is the the direction of the offset.

From the codes, you can check it :

(lines 979-1023)


(lines 407-484)