Topographic position disallowed in vectors query but would be useful for tracking #2599
Description
With these example definitions
DSN_goldstone = '257@399'
SSN_millstone = {'lon':-71.490967, 'lat':42.617442, 'elevation':0.127}
epochs = {'start': '1998-01-23 06:00:00', 'stop': '1998-01-23 12:00:00', 'step': '1m'}
spacecraft='NEAR'
the call Horizons(id=spacecraft, location=DSN_goldstone, epochs=epochs).vectors() returns topocentric range and range rate representative of Doppler tracking from DSN Goldstone in this case. The equivalent call Horizons(id=spacecraft, location=SSN_millstone, epochs=epochs).vectors(), to compare radar range from MIT's Haystack is refused with ValueError: cannot use topographic position in statevectors query, solely because of its location argument format.
This seems inconsistent, and perhaps the first query should be also blocked for violating the spirit of the vectors query. However, I feel the Horizons topocentric range and range rate would be a reliable reference for cross-checking radar or telemetry tracking of satellites.