LDI DIGISONDE 4D - Science Modes and Data Products

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DIGISONDE-4D
SYSTEM MANUAL
VERSION 1.2.11
SECTION 3 - OPERATING INSTRUCTIONS 3-7
different schedules for daytime and nighttime. Programming the Digisonde
®
to switch schedules automatically
is further discussed in Chapter 2.
SCIENCE MODES AND DATA PRODUCTS
3:5. The following types of scientific measurements are available for the Digisonde
®
operations:
1) Ionogram
(a) Vertical Incidence (VI) ionogram:
• VI ionogram with Doppler analysis of echoes
• VI Doppler ionogram with evaluation of the echo’s angle of arrival
Multi-beam processing
Source interferometry processing
• VI Doppler ionogram with multi-beam processing and two frequency precision ranging
(b) Oblique Incidence (bi-static) ionogram between two Digisonde
®
2) Drift measurement (detection of multiple echoes and evaluation of their source velocities).
3) Passive RF Sensing mode for monitoring transmitters of opportunity.
3:6. Digisonde
®
employs data processing software to obtain derived data products from acquired ionogram
and drift measurement data:
1) Ionogram-derived data
(a) Automatically scaled ionospheric characteristics, ionogram traces, and electron density profile
(b) Maximum Usable Frequency (MUF) report
(c) Directogram showing a daily plot of oblique echoes
2) Drift-derived data
(a) Skymap showing location of reflection sources
(b) Drift velocity derived in the assumption of a bulk motion of plasma across the station
(c) Zenith and azimuth of the ionospheric tilt
3:7. Figure 3-2 presents an overview of the Digisonde
®
data products in terms of their origin, data storage
and display options. The upper panel enlists science data types that are acquired in the process of Digisonde
®
measurements. Yellow circles are used to denote created data file types. In addition to the three major science
data modes, ionogram (RSF+SBF), drift (DFT), and Passive RF Sensing (TAV), it is possible to store raw sam-
ple data (RAW). The rest of data products are derived using data post-analysis software that runs autonomously
(the lower panel). Arrows in the Figure 3-2 indicate data flow for derivation and display of the products. Two
types of display are distinguished, real-time monitoring of the measurement process, and images available for
viewing over the Internet (Web displays).