Proposal Identi cation No.: T1035 Date Received: 1997-Jan-29 16:25:39 Technical Page Proposal Type: Regular General Category: Terrestrial Aeronomy Sub-Category: Optical Observation Category: Ionospheric Total Time Requested: 48 hours Hours Proposal Title: Mesoscale electric elds and plasma instabilities associated with zonally propa- gating TID's ABSTRACT: We wish to determine the electric eld associated with mesoscale airglow bands known to occur via Arecibo. ... Maybe Part of the observing run. ...

... 2.3 Data acquisition Spectra generated by the Multibeam correlator contain the usual structure seen in spectra from other H i instruments: a bandpass spectrum which is the sum of the sky , ground and receiver temperatures multiplied by the product of the filters in the receiver chain; superimposed on this is a noise ... Note also that sources extended much beyond ,40 arcmin can be imaged poorly in HIPASS images because of the bandpass sidelobe effect described in Section 3.3. ...