ITSPECTRALANALYSIS

Enable and configure spectral analysis on receiver

Platform:

OEM719, OEM729, OEM7500, OEM7600, OEM7700, OEM7720, PwrPak7, CPT7, CPT7700, SMART7

Use this command to view the spectrum in a range of frequencies. The ITSPECTRALANALYSIS command enables and configures the spectral analysis. The spectrum is viewed by plotting the PSD samples in the ITPSDFINAL log.

Decreasing the update period or increasing the FFT size will impact receiver idle time. The idle time should be monitored to prevent adverse effects on receiver performance.

Due to the high volume of data, a higher bandwidth medium, such as USB or Ethernet, is recommended when monitoring signals using the Interference Toolkit.

To enable and configure spectral analysis on the secondary antenna of dual antenna receivers (OEM7720, PwrPak7D, PwrPak7D-E1, PwrPak7D-E2 and CPT7), use the ITSPECTRALANALYSIS_1 command.

Message ID: 1967

Abbreviated ASCII Syntax:

ITSPECTRALANALYSIS mode [frequency] [updateperiod] [FFTsize] [timeavg] [integration_window]

Factory Default:

ITSPECTRALANALYSIS off

ASCII Example:

ITSPECTRALANALYSIS predecimation gpsl1 500 1K 20 1

Field	Field Type	ASCII Value	Binary Value	Description	Format	Binary Bytes	Binary Offset
1	Command header	-	-	ITSPECTRALANALYSIS header This field contains the command name for abbreviated ASCII or the message header for ASCII (see page 1) or Binary (see page 1).	-	H	0
2	mode	See Table: Data Sources for PSD Samples		Set the view mode.	Enum	4	H
3	frequency	See Table: Frequency Types		Set the frequency band to view.	Enum	4	H+4
4	updateperiod	50 to 100000		The spectrum update rate in milliseconds. The update period is limited by the FFT size chosen. For 32k the minimum update period is 100 ms and for 64k the minimum update period is 200 ms. (default = 1000)	Ulong	4	H+8
5	FFTsize	See Table: FFT Sizes		The frequency resolution of the spectrum. (default = 1k)	Enum	4	H+12
6	timeavg	0 to 50		Time averaging window in seconds. 0 means no time averaging. (default = 10)	Ulong	4	H+16
7	integration window	1 to 1024		The integration window size of FFT samples. 1 means no integration. (default = 5)	Ulong	4	H+20

Data Sources for PSD Samples
Binary Value	ASCII Value	Description
0	OFF	Disable spectral analysis
1	PREDECIMATION	Perform spectrum analysis on the pre-decimated spectrum. This can be used to see a wide view of the spectrum for an RF path (L1, L2 or L5).
2	POSTDECIMATION	Perform spectrum analysis on the post-decimated spectrum. This is narrower than pre-decimation and is used to see the spectrum for a given signal.
3	POSTFILTER	Perform spectrum analysis on the post-filtered spectrum. This can be used when either bandpass or notch filters have been enabled to see the spectrum after the filters are applied.

The post-filter spectrum is not available for the Galileo AltBOC frequency. Only the pre-decimation and post-decimation spectrums are available for Galileo AltBOC.

Frequency Types
Binary Value	ASCII Value	Description
0	GPSL1	GPS L1 frequency
1	GPSL2	GPS L2 frequency
2	GLONASSL1	GLONASS L1 frequency
3	GLONASSL2	GLONASS L2 frequency
4	Reserved
5	GPSL5	GPS L5 frequency
61	LBAND	Inmarsat L-Band frequency
7	GALILEOE1	Galileo E1 frequency
8	GALILEOE5A	Galileo E5A frequency
9	GALILEOE5B	Galileo E5B frequency
10	GALILEOALTBOC	Galileo AltBOC frequency
11	BEIDOUB1	BeiDou B1 frequency
12	BEIDOUB2	BeiDou B2I frequency
13	QZSSL1	QZSS L1 frequency
14	QZSSL2	QZSS L2 frequency
15	QZSSL5	QZSS L5 frequency
16	QZSSL6	QZSS L6 frequency
17	GALILEOE6	Galileo E6 frequency
18	BEIDOUB3	BeiDou B3 frequency
19	GLONASSL3	GLONASS L3 frequency
20	NAVICL5	NavIC L5 frequency
21	BEIDOUB1C	BeiDou B1C frequency
22	BEIDOUB2A	BeiDou B2a frequency
23	BEIDOUB2B	BeiDou B2b frequency

FFT Sizes
Binary Value	ASCII Value	Description
0	1K	1K FFT, 1024 samples
1	2K	2K FFT, 2048 samples
2	4K	4K FFT, 4096 samples
3	8K	8K FFT, 8192 samples
4	16K	16K FFT, 16384 samples
5	32K	32K FFT, 32768 samples
6	64K	64K FFT, 65536 samples

The 64k FFT is not available in post-decimation or post-filter modes.