Specification

This page presents MOMIJI’s key technical specifications — link budget, transmission format, and power budget.

Link Budget

Calculation tables for three uplink paths (UHF-UP / VHF-UP x2) and four downlink paths (CW-DOWN / UHF-DOWN / VHF-DOWN x2), based on the TSUDANUMA ground station. The uplink side (I-I to I-III) is reproduced as-is, including a formula error in the source spreadsheet that leaves path loss and later fields showing #NUM!.

Link budget calculation table (transmit side)

Link budget calculation table (receive side / Eb-N0 and SNR methods)

Transmission Format

MOMIJI’s downlink data formats, including the AX.25 header structure and HK data bit assignments.

CW Downlink Format

GMSK Downlink Format

HK Downlink Format

HSHK Format

LSHK Format

APRS Log Format

Power Budget

Simulated battery state-of-charge (SOC) trends for each mission.

Chiba-ny mission battery SOC trend

Pollen-forecast mission battery SOC trend

Battery SOC trend during 20-minute in-vehicle operation (single run)

Battery SOC trend during 20-minute in-vehicle operation (continuous operation)

Ecological survey (muntjac tracking) battery SOC trend

Battery SOC trend, bus system only

Battery SOC trend across all missions