This satellite uses amateur radio frequency band of 145 MHz band for uplink and 435 MHz band for downlink. On this page, we release the telemetry data format of NEXUS.
【DownLink frequency】
CW-FM
437.075MHz
QPSK
435.900MHz
FSK
435.900MHz
TRP
435.880MHz - 435.910MHz
【UpLink frequency】
TRP
145.930MHz - 145.900MHz
【Telemetry format】
・CW telemetry format
CW transmits satellite data as beacon. In this section, we introduce the CW telemetry format. This satellite has some transmission pattern. And we call these pattern as mode.
These CW modes are shown as follow.
When the satellite condition is steady, CW mode is Normal mode. If the satellite voltage is in danger, CW mode changes to Power saving mode. In Custom mode, satellite data is arbitrarily selected and transmitted.
Line check mode transmits line check result. The line check is to confirm whether communication with each system of the satellite is normal. And line check is operated by FMR. Upplink reply mode is operated when the satellite receives uplink.
CW telemetry formats except Upplink reply mode are shown as follow.
If you find more detail, please check CW telemetry format (pdf) on the following link.
・FM telemetry format
NEXUS performs FM packet communication conforming to the AX.25 protocol : AFSK/1200bps, GMSK/9600bps. The format of the packet is as follows.
In NEXUS, the contents of the Info section consists of an identification number, a packet number, the uplink number, and main data. Main data is mainly HK data, image data, Field Intensity: FI data. The amount of each data is different. For detailed information on the contents and amount of data, please see FM telemetry format (pdf) on the following link.
