LDI Intellectual Property.
Not for secondary distribution or replication, in part or entirety.
DIGISONDE-4D
SYSTEM MANUAL
VERSION 1.2.11
5-60 SECTION 5 - SYSTEM SOFTWARE – ANNEX C
ANNEX C
DCART INTEFACE CONTROL DOCUMENT FOR DATA
PRODUCTS
UNIFORM MEASUREMENT STORAGE, VERSION 3
General considerations
5:141. UMS stands for Uniform Measurement Storage, which is the format for DPS4D data. UMS comprises
many different types of DPS4D science data; ionograms, drift, raw, and others. This format is comprehensive in
the sense that it contains not only the data produced by DPS4D, but also all supplemental information that is
necessary for data understanding and analysis.
5:142. UMS format is backward compatible format, it is assumed that not only the latest version of the format
will be maintained by up-to-date software (DCART, SAO-X, Drift-X), but all previous UMS versions will be
also compatible with it. UMS version 3 is the current/latest version. Also be aware, the format includes many
different structures, and several of the substructures are also version controlled. The version of the substructure
cannot be greater than UMS version.
5:143. Science Data are arranged in Measurements. From a general point of view, Measurements are charac-
terized by Location, Time, Program, and Applied Processes List, and contain scientific data that was collected
at the Location and Time by implementing aProgram and then processed further by applying the processes in
the Applied Processes List.
5:144. Measurement data is produced by collecting a series of samples at a program defined rate of either 100
Hz or 200 Hz. Incoming data samples are collected in chunks called “looks” which can contain either 256 or
512 samples per channel (program depending). The term “look” is in reference to the period of time during
which the equipment collects samples while listening (or looking) for some signal of interest. This output with-
out further processing is known as Raw Science Data.
5:145. Further Raw Science Data will undergo several known processing stages. Here they are in the sequence
applied:
1. Channel equalizing. Mandatory. No data reduction.
2. Radio Frequency Interference Mitigation. Recommended, but may be omitted. No data reduction.
3. Pulse Compression, if applicable. No data reduction.
4. Sum complementary codes, if applicable. Data are reduced by two times.
5. Regroup by frequencies and calculate Dopplers. No data reduction.
5:146. At this point processing splits into two branches depending on Program purpose to either produce an
Ionogram “snapshot” of ionosphere taken over a large number of frequencies with coarse Doppler resolution, or
Drift Data, a high resolution Doppler measurement of the ionosphere taken over a small number of selected
frequencies.
To Next Page
Loading...
General