電子航法研究所研究発表会（第16回平成28年６月）

㸯㸰㸬*36/ ಙྕࡢ᪂⯟ἲ࣓ࢵࢭ࣮ࢪࡢ฼⏝ྍ⬟ᛶ⯟ἲࢩࢫࢸ࣒㡿ᇦ ͤ໭ᮧගᩍ㸪㯞⏕㈗ᗈ㸪ᆏ஭୔Ὀ1 ⫼ᬒ
1.1 GNSS ࡢ㏆௦໬
㏆ᖺ㸪ேᕤ⾨ᫍࢆ฼⏝ࡋ࡚఩⨨ᶆᐃࡍࡿ඲ᆅ⌫⯟ἲ⾨ᫍࢩࢫࢸ࣒㸦GNSS: Global Navigation
Satellite Systems㸧ࡢ㏆௦໬ࡀ㐍ࡵࡽࢀ࡚࠸ࡿࠋලయⓗ࡟ࡣ㸪⡿ᅜ GPS ࡢ➨ 3 Ẹ㛫⏝ ఩ಙྕ㸦L5㸧ࡢᨺ㏦ࡸ㸪㟢ᅜ GLONASS ࡀᨺ㏦ࡍࡿ
ᚑ᮶ࡢ FDMA ᪉ᘧಙྕ࡟ᑐࡋ࡚᪂ࡋ࠸ CDMA᪉ᘧಙྕࡢ㏣ຍ㸪ࡲࡓḢᕞࡢ Galileo ࡸ୰ᅜࡢBeiDou ࡜࠸ࡗࡓ᪂ࡋ࠸ GNSS ࡢᒎ㛤➼࡛࠶ࡿࠋ
1.2 SBAS ࡢḟୡ௦໬
GNSS ࡢ㏆௦໬ࡀ㐍ࡴ୰㸪㟼Ṇ⾨ᫍᆺ⾨ᫍ⯟ἲ ⿵ ᙉ ࢩ ࢫ ࢸ ࣒ 㸦 SBAS: Satellite Based
Augmentation System㸧ࡢḟୡ௦つ᱁ࡢ᳨ウࡀ⾜ࢃࢀ࡚࠸ࡿࠋ⾨ᫍ⯟ἲ⿵ᙉࢩࢫࢸ࣒࡜ࡣ㸪GNSS ࡢ␗ᖖ≧ែࢆ┘どࡍࡿࡇ࡜࡛ GNSS఩ࢆ⿵ᙉࡋ㸪ࡑࡢᏳ඲ᛶ࡜ಙ㢗ᛶࢆᢸಖࡍࡿࢩࢫࢸ࣒࡛࠶ࡿࠋ⯟✵ᶵࡀ⯟ἲ࡟࠾࠸࡚ GNSS఩ࢆ฼⏝ࡍࡿ㝿࡟ࡣ㸪⾨ᫍ⯟ἲ⿵ᙉࢩࢫࢸ࣒࡟ࡼࡿ ఩ࡢ⿵ᙉࡀᚲ㡲࡛࠶ࡿࠋSBAS ࡜ࡣ㸪⾨ᫍ⯟ἲ⿵ᙉࢩࢫࢸ࣒ࡢ୍✀࡛࠶ࡾ㸪GNSS఩ಙྕࡢㄗᕪࡸ
␗ᖖ≧ែࢆᆅୖ࡟タ⨨ࡋࡓཷಙᶵࢿࢵࢺ࣮࣡ࢡࢆ⏝࠸࡚┘どࡋ㸪ࡑࡢ᝟ሗࢆ㟼Ṇ㌶㐨ୖࡢ⾨ᫍࢆ௓ࡋ࡚⯟✵ᶵ㸦࣮ࣘࢨ㸧࡟㏻▱ࡍࡿࡇ࡜࡛GNSS ఩ࢆ⿵ᙉࡍࡿࢩࢫࢸ࣒࡛࠶ࡿࠋ⌧⾜ࡢ SBAS ࡛ࡣ㸪GPS ࡢ L1 ᖏ ఩ಙྕࢆ┘どࡍࡿࡇ࡜࡛⿵ᙉ᝟ሗࢆసᡂࡋ㸪࣮ࣘࢨ࡟ఏ
㏦ࡋ࡚࠸ࡿࠋࡑࢀ࡟ᑐࡋ࡚ḟୡ௦ SBAS ࡣ㸪⿵ᙉ ࡍ ࡿ GNSS ࢆ ቑ ࡸ ࡍ ࣐ ࣝ ࢳ ࢥ ࣥ ࢫ ࢸ ࣞ ࣮ࢩࣙࣥ໬ࡍࡿࡇ࡜࡛⾨ᫍᩘࡢቑຍ࡟ࡼࡿ ఩⋡ࡢྥୖࢆᅗࡾ㸪ࡲࡓ㸪 ఩ಙྕ࡟᪂ࡋࡃ L5 ᖏࢆ฼⏝ࡍࡿ 2 ࿘Ἴ໬ࡍࡿࡇ࡜࡛㸪㟁㞳ᅪᨐ஘᫬➼ࡢ ఩⢭ᗘࡢྥୖࢆᅗࡿࠋࡇࡢࡼ࠺࡞ḟୡ௦໬࡟ࡼࡗ࡚㸪SBAS ࡟ࡼࡿ⿵ᙉ ఩ࡢ฼⏝ྍ⬟ᛶࡢྥୖࡀᮇᚅࡉࢀ࡚࠸ࡿࠋ
1.3 ḟୡ௦ SBAS ࡢ᳨ウㄢ㢟ḟୡ௦ SBAS ࡣ㸪ࡑࡢつ᱁໬࡟ྥࡅࡓከࡃࡢㄢ㢟ࡢ᳨ウࡀḢ⡿ㅖᅜ୺ᑟࡢࡶ࡜┠ୗ㐍ࡵࡽࢀ࡚࠸ࡿࠋᮏሗ࡛ࡣ㸪ࡑࢀࡽ᳨ウㄢ㢟ࡢ 1 ࡘ࡜ࡋ࡚㸪GPS ࡢ L5 ᖏ ఩ಙྕ࡟㔜␚ࡉࢀ࡚ᨺ㏦ࡉ
ࢀ࡚࠸ࡿ᪂ࡋ࠸⯟ἲ࣓ࢵࢭ࣮ࢪ㸦CNAV: Civil
Navigation Message㸧ࡢḟୡ௦ SBAS ࡟࠾ࡅࡿ฼⏝ྍ⬟ᛶ࡟ࡘ࠸࡚㆟ㄽࡍࡿࠋࡑࡋ࡚㸪⌧⾜SBAS ࡛ࡶ฼⏝ࡋ࡚࠸ࡿᚑ᮶ࡢ⯟ἲ࣓ࢵࢭ࣮ࢪ㸦LNAV: Legacy Navigation Message㸧࡜ CNAVࡢ࡝ࡕࡽࡀḟୡ௦ SBAS ࡢ⿵ᙉ࡟㐺ࡍࡿ⯟ἲ࣓ࢵࢭ࣮ࢪ࡛࠶ࡿࡢ࠿ࢆ᫂ࡽ࠿࡟ࡍࡿࠋホ౯ࡢ᪉㔪࡜ࡋ࡚㸪CNAV ࡢ⾨ᫍ㌶㐨࣭᫬ィ⢭ᗘࢆホ౯ࡍࡿࡇ࡜࡛㸪LNAV ࡟ᑐࡍࡿ CNAVࡢඃ఩ᛶࢆホ౯ࡍࡿࠋࡇࡇ࡛㸪CNAV ࡢ⾨ᫍ㌶㐨࣭᫬ィ⢭ᗘ࡟㛵ࡍࡿホ౯ࡣ᪤࡟ᐇ᪋ࡉࢀ࡚࠾ࡾ㸪LNAV ࡟ᑐࡍࡿඃ఩ᛶࡣ᫂ࡽ࠿࡟ࡉࢀ࡚࠸ࡿ [1][2] ࠋ ࡋ ࠿ ࡋ ࡞ ࡀ ࡽ ࡑ ࢀ ࡽ ࡢ ከ ࡃ ࡣ 㸪
CNAV ࢆ GPS ࡢ༢⊂ ఩࡛฼⏝ࡍࡿ࡜࠸࠺ほⅬ࠿ࡽホ౯ࡀ⾜ࢃࢀ࡚࠸ࡿࠋᮏሗ࡛ࡣ㸪ḟୡ௦
SBAS ࡟࠾ࡅࡿ⿵ᙉ࡛฼⏝ࡍࡿ࡜࠸࠺ほⅬ࠿ࡽ
CNAV ࡢ⾨ᫍ㌶㐨࣭᫬ィ⢭ᗘࡢホ౯ࢆᐇ᪋ࡍࡿࠋ
ࡲࡓ㸪CNAV ࢆḟୡ௦ SBAS ࡛฼⏝ࡍࡿࡇ࡜࡛㸪⾨ᫍ㌶㐨࣭᫬ィ⢭ᗘ௨እ࡛⏕ࡌࡿᙳ㡪࡜ࡋ࡚㸪
L5 ᖏ I-Q ┦ಙྕࡢ㑅ᢥ࡟㛵ࡍࡿၥ㢟࡟ࡘ࠸࡚ࡶゝཬࡍࡿࠋ
2 SBAS ࡜ࡣ2.1 ⌧⾜ SBAS
⌧ ⾜ ࡢ SBAS つ ᱁ ࡣ 㸪 ᅜ 㝿 Ẹ 㛫 ⯟ ✵ ᶵ 㛵㸦ICAO㸧ࡀ⾨ᫍ⯟ἲ⿵ᙉࢩࢫࢸ࣒つ᱁ࡢ୍✀[3]࡜ࡋ࡚ᐃࡵ࡚࠾ࡾ㸪⯟✵⯟ἲ࡟࠾࠸࡚ GPSࢆ฼⏝ࡍࡿ㝿࡟ࡣ㸪⾨ᫍ⯟ἲ⿵ᙉࢩࢫࢸ࣒࡟ࡼࡾ㐺ษ࡞⿵ᙉࢆ᪋ࡋ࡚ ఩ࡢᏳ඲ᛶ࡜ಙ㢗ᛶࢆ☜ಖࡍࡿࡇ࡜࡜ࡋ࡚࠸ࡿࠋ
⌧⾜ SBAS ࡣ GPS ࡢ L1 ᖏಙྕ㸦L1-C/A㸧ࢆ฼⏝ࡋࡓ 1 ࿘Ἴ ఩ࢆ⿵ᙉࡍࡿࡓࡵ࡟㸪ᆅୖ࡟タ⨨ࡉࢀࡓཷಙᶵࢿࢵࢺ࣮࣡ࢡ࡟ࡼࡗ࡚
GPS ࡢ ఩ಙྕࢆ┘どࡋ㸪GPS ⾨ᫍࡢ␗ᖖ≧ែࡸ ఩ࡢㄗᕪ᝟ሗࢆ㸪⿵ᙉ᝟ሗ࡜ࡋ࡚㟼Ṇ⾨
ᫍࢆ⤒⏤ࡋ࡚࣮ࣘࢨ࡟ᨺ㏦ࡋ࡚࠸ࡿ㸦ᅗ 2.1㸧ࠋࡇࡇ࡛ㄗᕪ᝟ሗ࡜ࡣ㸪⯟ἲ࣓ࢵࢭ࣮ࢪ࠿ࡽィ⟬─ 72 ─電子航法研究所研究発表会（第16回平成28年６月）

ࡍࡿࡇ࡜ࡀ࡛ࡁࡿ⾨ᫍࡢ఩⨨ࡸ㸪ᦚ㍕ࡋ࡚࠸ࡿཎᏊ᫬ィ࡜ GPS ࡀᇶ‽࡜ࡍࡿ᫬้⣔㸦GPST㸧࡜ࡢᕪ࡟㛵ࡍࡿㄗᕪ᝟ሗ࡛࠶ࡿࠋࡲࡓ㸪1 ࿘Ἴ఩࡛ၥ㢟࡜࡞ࡿ㟁㞳ᅪఏᦙ㐜ᘏ࡟ᑐࡋ࡚㸪ఏᦙ㐜ᘏ㔞࣐ࢵࣉࡶ⿵ᙉ᝟ሗ࡜ࡋ࡚ᨺ㏦ࡋ࡚࠸ࡿࠋ
࣮ࣘࢨࡣࡇࢀࡽࡢ⿵ᙉ᝟ሗࢆ GPS఩࡟㐺⏝ࡍࡿࡇ࡜࡛ ఩⢭ᗘࡢྥୖࢆᅗࡿࠋ
2.2 ḟୡ௦ SBAS
ḟୡ௦ࡢ SBAS つ᱁ࡣ㸪㏆௦໬ࡀ㐍ࡴ GNSS
ࢆ฼⏝ࡋࡓ᪂ࡋ࠸⾨ᫍ⯟ἲ⿵ᙉࢩࢫࢸ࣒࡛࠶ࡾ㸪
ICAO ࡸḢ⡿ㅖᅜ୺ᑟ࡟ࡼࡿ SBAS ┦஫㐠⏝ᛶ఍㆟㸦IWG: Interoperability Working Group 㸧࡟࠾࠸࡚㸪つ᱁໬ࡢࡓࡵࡢ᳨ウࡀ㐍ࡵࡽࢀ࡚࠸ࡿࠋ
ᮏሗ࡟࠾ ࡅ ࡿḟୡ௦ SBAS ࡢ௙ ᵝࡣ㸪 SBASIWG ࡛ᥦฟࡉࢀࡓḟୡ௦ SBAS ࡟㛵ࡍࡿ࢖ࣥࢱ࣮ࣇ࢙࢖ࢫ⟶⌮ᩥ᭩㸦ICD: Interface Control
Document㸧ࡢࢻࣛࣇࢺ∧[4]ࢆඖ࡟㆟ㄽࡍࡿࠋ⌧⾜ SBAS ࠿ࡽࡢ୺࡞ኚ᭦Ⅼࡣ㸪⿵ᙉᑐ㇟ࡢ
GNSS ࡜ ࡋ ࡚ 㸪 ⌧ ⾜ ࡢ GPS ࡟ GLONASS 㸪Galileo㸪BeiDou ࡜࠸࠺᪂ࡋ࠸ GNSS ࢆ㏣ຍࡍࡿ ࣐ ࣝ ࢳ ࢥ ࣥ ࢫ ࢸ ࣞ ࣮ ࢩ ࣙ ࣥ 㸦 MC: MultiConstellation㸧࡟ᑐᛂࡍࡿⅬ࡜㸪⌧⾜ࡢ L1 ᖏ఩ಙྕ࡟㸪᪂ࡋࡃ L5 ᖏ ఩ಙྕࢆ㏣ຍࡍࡿ 2
࿘Ἴ㸦DF: Dual-Frequency㸧 ఩࡟ᑐᛂࡍࡿⅬ࡛࠶ࡿ㸦ᅗ 2.2㸧ࠋMC ᑐᛂ࡟ࡼࡿ⾨ᫍᩘࡢቑຍ࡜㸪DF ᑐᛂ࡟ࡼࡿ㧗⢭ᗘ࡞㟁㞳ᅪ㐜ᘏ᥎ᐃࡀᮇᚅ࡛ࡁࡿࡓࡵ㸪⯟✵⯟ἲ࡟࠾ࡅࡿ GNSS
఩ࡢ฼⏝ྍ⬟ᛶࡢྥୖࡀᮇᚅࡉࢀ࡚࠸ࡿࠋ
ḟୡ௦ SBAS ࡟࠾ࡅࡿ ఩⢭ᗘྥୖࡢࡓࡵࡢ
⿵ṇ᪉ᘧࡣ㸪⌧⾜ SBAS ࡜ᇶᮏⓗ࡟ྠᵝ࡛࠶ࡾ㸪⯟ἲ࣓ࢵࢭ࣮ࢪ࡟ྵࡲࢀࡿ⾨ᫍ㌶㐨࣭᫬ィࡢㄗᕪ᝟ሗࢆᨺ㏦ࡍࡿࡇ࡜࡛ ఩⢭ᗘࡢྥୖࢆᅗࡿࠋ࡞࠾㸪DF఩࡟ᑐᛂࡍࡿࡇ࡜࡛࣮ࣘࢨࡀ㟁㞳ᅪఏᦙ㐜ᘏ㔞ࡢ᥎ᐃࡀྍ⬟࡟࡞ࡿࡓࡵ㸪㟁㞳ᅪ㐜ᘏ⿵ṇࡣᨺ㏦ࡉࢀ࡞࠸ぢ㎸ࡳ࡛࠶ࡿࠋ2.3 ḟୡ௦ SBAS ࡢ᳨ウㄢ㢟
SBAS IWG ࡛ࡣ㸪ḟୡ௦ SBAS ࡢつ᱁໬࡟ྥࡅࡓከࡃࡢㄢ㢟࡟ࡘ࠸࡚┠ୗ᳨ウࡀ㐍ࡵࡽࢀ࡚࠸ࡿࠋᮏሗ࡛ࡣ㸪ࡑࢀࡽ᳨ウㄢ㢟ࡢ 1 ࡘ࡜ࡋ࡚㸪ḟୡ௦ SBAS ࡀ⿵ᙉࡍࡿ⯟ἲ࣓ࢵࢭ࣮ࢪࡢ㑅ᢥ࡟ࡘ࠸࡚㆟ㄽࡍࡿࠋᮏㄢ㢟ࡣ㸪⌧⾜ SBAS ࡛ࡣ⯟ἲ࣓ࢵࢭ࣮ࢪ࡜ࡋ࡚㸪GPS ࡢ L1-C/A ಙྕ࡛
ᨺ㏦ࡉࢀ࡚࠸ࡿᚑ᮶ࡢ⯟ἲ࣓ࢵࢭ࣮ࢪ㸦LNAV:
Legacy Navigation Message㸧ࡢࡳ฼⏝ྍ⬟࡛࠶ࡿࡓࡵ㸪ࡑࡢㄗᕪ᝟ሗࢆ᥎ᐃ࣭ᨺ㏦ࡋ࡚࠸ࡿࠋ
ࡑࢀ࡟ᑐࡋ࡚ḟୡ௦ SBAS ࡛ࡣ㸪L5 ᖏ ఩ಙྕࢆ᪂ࡓ࡟฼⏝ࡍࡿࡇ࡜ࡀ࡛ࡁࡿࡓࡵ㸪ࡑࢀ࡟㔜 ␚ ࡉ ࢀ ࡓ ᪂ ࡋ ࠸ ⯟ ἲ ࣓ ࢵ ࢭ ࣮ ࢪ 㸦 CNAV:
Civil Navigation Message㸧࡜ LNAV ࡢ 2 ࡘࡢ⯟ἲ࣓ࢵࢭ࣮ࢪ࡟ᑐࡋ࡚⿵ᙉ᝟ሗࢆసᡂࡍࡿࡇ࡜ࡀྍ⬟࡛࠶ࡿࠋࡑࡢࡓࡵ㸪࡝ࡕࡽࡢ⯟ἲ࣓ࢵࢭ࣮ࢪ࡟ᑐࡋ࡚⿵ᙉ᝟ሗࢆసᡂࡋᨺ㏦ࡍࡿ࠿Ỵᐃࡍࡿᚲせࡀ࠶ࡿ࡜࠸࠺᳨ウㄢ㢟࡛࠶ࡿࠋ>ϭᖏ఩ಙྕ䝴䞊䝄ᆅୖཷಙᶵ䝛䝑䝖䝽䞊䜽ᅗ 2.1 ⌧⾜ SBAS ࡢᴫせ>ϭᖏ ఩ಙྕ>ϱᖏ ఩ಙྕ'ĂůŝĞŽ

䝴䞊䝄ᆅୖཷಙᶵ䝛䝑䝖䝽䞊䜽ᅗ 2.2 ḟୡ௦ SBAS ࡢᴫせ3 ⯟ἲ࣓ࢵࢭ࣮ࢪ
⯟ἲ࣓ࢵࢭ࣮ࢪ࡜ࡣ㸪GPS ⾨ᫍࡢ఩⨨᝟ሗࡸ㸪ᦚ㍕ࡋ࡚࠸ࡿཎᏊ᫬ィࡢ GPST ࡟ᑐࡍࡿㄗᕪ᝟ሗ࡛࠶ࡿࠋࡇࢀࡽࡣ ㊥ಙྕ࡟㔜␚ࡉࢀ࣮ࣘࢨ࡟ᨺ㏦ࡉࢀ࡚࠾ࡾ㸪L1-C/A ಙྕ࡜ L5 ಙ
ྕ࡛ᨺ㏦ࡉࢀࡿ⯟ἲ࣓ࢵࢭ࣮ࢪࢆࡑࢀࡒࢀLNAV ࡜ CNAV ࡜࿧ࡪࠋGPS ࡢ୍⯡ⓗ࡞ ఩ᡭἲ࡛࠶ࡿ༢⊂ ఩࡛ࡣ㸪⯟ἲ࣓ࢵࢭ࣮ࢪ࠿ࡽィ⟬࡛ࡁࡿ⾨ᫍࡢ఩⨨࡜᫬ィࡀṇ☜࡟᪤▱࡛࠶ࡿ࡜⪃࠼࡚㸪⾨ᫍ㸫ཷಙᶵ㛫ࡢ㊥㞳ࢆಙྕࡢఏᦙ᫬㛫࠿ࡽ᥎ᐃࡍࡿࡇ࡜࡛㸪ཷಙᶵ఩⨨ࢆ ఩ࡍࡿࠋ

─ 73 ─

電子航法研究所研究発表会（第16回平成28年６月）

3.1 Legacy Navigation Massage (LNAV)LNAV ࡣ GPS ࡢ L1 ࿘ Ἴ ᩘ ᖏ 㸦 1575.42[MHz]㸧ࡢ L1-C/A ࡜࿧ࡤࢀࡿ ఩ಙྕ࡛ఏ㏦㏿ᗘ 50 [bps]࡛ᨺ㏦ࡉࢀ࡚࠾ࡾ㸪ᚑ᮶ࡢ GPS ༢⊂ ఩ࡸ㸪⌧⾜ SBAS ࡛฼⏝ࡉࢀ࡚࠸ࡿࠋ⯟ἲ࣓ࢵࢭ࣮ࢪࡣ㸪⾲ 3.1 ࡟♧ࡍ 15 ಶࡢ⾨
ᫍ㌶㐨せ⣲㸦࢚ࣇ࢙࣓ࣜࢫ㸧࡜࢚ࣇ࢙࣓ࣜࢫඖ
ᮇ toe㸪3 ḟࡢ⾨ᫍ᫬ィ⿵ṇ㡯࠾ࡼࡧ᫬ィ⿵ṇࡢඖᮇ toc ࢆᨺ㏦ࡋ࡚࠸ࡿࠋ⾨ᫍ఩⨨࣭᫬ィㄗᕪࡢィ⟬࡟㛵ࡍࡿヲ⣽ࡣ GPS ࡢ ICD[5]࡟グ㍕ࡉࢀ࡚࠸ࡿࠋࡲࡓ㸪LNAV ࡣ⯟ἲ࣓ࢵࢭ࣮ࢪࡢⓎ⾜␒ྕ㸦IOD: Issue of Data㸧ࢆᨺ㏦ࡋ࡚࠾ࡾ㸪ࡇࢀࢆ฼⏝ࡍࡿࡇ࡜࡛㸪࣮ࣘࢨࡣ࢚ࣇ࢙࣓ࣜࢫࡢ㌶㐨せ⣲ࡢ್ࡀኚ᭦㸦᭦᪂㸧ࡉࢀࡓሙྜࡢุูࡸ㸪࢚ࣇ࢙࣓ࣜࢫࡢ᝟ሗࢭࢵࢺࡢࣂ࣮ࢪࣙࣥ⟶⌮࡞࡝ࡀྍ⬟࡛࠶ࡿࠋ3.2 Civil Navigation Massage (CNAV)CNAV ࡣ L5 ࿘Ἴᩘᖏ㸦1176.45 [MHz]㸧ࡢ I┦㸦In-phase㸧࡛ L5I5 ࡜࿧ࡤࢀࡿ ఩ಙྕ࡛ఏ㏦㏿ᗘ 50[bps]࡛ᨺ㏦ࡉࢀ㸪2013 ᖺ࠿ࡽᐇ㝿࡟
ᨺ㏦ࢸࢫࢺ ࡀ⾜ࢃࢀ࡚ ࠸ࡿ[7]ࠋࡲ ࡓ㸪CNAV
࡟㛵ࡍࡿヲ⣽ࡣ㸪GPS ࡢ L5 ᖏಙྕ࡟㛵ࡍࡿ
ICD[6]࡟グ㍕ࡉࢀ࡚࠸ࡿࠋ
ࡇࡇ࡛㸪L5 ᖏ࡛ࡣ L5I5 ಙྕ࡜ࡣู࡟㸪Q ┦㸦Quadrature-phase㸧࡟࠾࠸࡚㸪L5Q5 ࡜࿧ࡤࢀࡿ ఩ಙྕࡶᨺ㏦ࡉࢀ࡚࠸ࡿࠋࡇࡢෆ㸪CNAV
ࡣ L5I5 ಙྕࡢࡳ࡟㔜␚ࡉࢀ࡚࠾ࡾ㸪L5I5 ಙྕࡣࢹ࣮ࢱಙྕ࡜ࡶ࿧ࡤࢀࡿࠋࡑࢀ࡟ᑐࡋ࡚㸪
L5Q5 ಙྕࡣࢹ࣮ࢱࡀ㔜␚ࡉࢀ࡞࠸ࡓࡵ㸪ࣃ࢖ࣟࢵࢺಙྕ࡜ࡶ࿧ࡤࢀ㧗⢭ᗘ࡞ ㊥⬟ຊࡀᮇᚅࡉࢀ࡚࠸ࡿ[8]ࠋࡘࡲࡾ㸪CNAV ࢆ฼⏝ࡋࡓ఩ࢆ⾜࠺ሙྜ㸪L5I5 ಙྕࡢࢺࣛࢵ࢟ࣥࢢࡀᚲせ࡛࠶ࡾ㸪㧗⢭ᗘ࡞ ㊥ࡀᮇᚅࡉࢀ࡚࠸ࡿL5Q5 ಙྕࢆ฼⏝ࡍࡿࡓࡵ࡟ࡣ㸪᭦࡟ಙྕ㏣ᑿ
࣮ࣝࣉࡢ㏣ຍࡀᚲせ࡛࠶ࡿⅬ㸪ὀពࢆせࡍࡿࠋCNAV ࡢ⾨ᫍ᫬ィ࣭㌶㐨᝟ሗࡣ㸪LNAV ࢆඖ࡟㧗⢭ᗘ໬ࡀᅗࡽࢀ࡚࠾ࡾ㸪୺࡞ኚ᭦࡜ࡋ࡚㸪⾲
3.1 ࡟♧ࡍ LNAV ࡢ⾨ᫍ㌶㐨せ⣲࡟㸪⾲ 3.2 ࡟♧ࡍ㌶㐨せ⣲ࡀ᪂ࡓ࡟㏣ຍࡉࢀ࡚࠸ࡿࠋ࡞࠾㸪⾲ 3.1 ࡢ ㌶ 㐨 㛗 ༙ ᚄ ࡢ ᰿ Aࡣ 㸪 ᇶ ‽ 㛗 ༙ ᚄ
AREF㸦= 26,559,710 [m]㸧࠿ࡽࡢᕪ'A ࢆ⏝࠸࡚ᘧ(3.1)ࡢࡼ࠺࡟ኚ᭦ࡉࢀ࡚࠸ࡿࠋࡲࡓ㸪LNAVࡀⓎ⾜ࡋ࡚࠸ࡿ IOD ࡀ CNAV ࡛ࡣⓎ⾜ࡉࢀ࡞࠸Ⅼ࡟ὀពࢆせࡍࡿࠋ

2A | AREF  'A

(3.1)

᪂ࡓ࡟㏣ຍࡉࢀࡓ⾲ 3.2 ࡢ㌶㐨せ⣲ࡣ㸪ࡑࢀࡒࢀᘧ(3.2)㸪ᘧ(3.3)࡟♧ࡍᵝ࡟㸪᫬้ tk ࡟࠾ࡅࡿ㌶㐨㛗༙ᚄ Ak ࡜ᖹᆒ㐠ື nk ࢆ࢚ࣇ࢙࣓ࣜ
ࢫඖᮇ toe ࠿ࡽ᫬㛫ఏ᧛ࡋ࡚ồࡵࡿ㝿࡟฼⏝ࡉࢀࡿࠋ࡞࠾㸪n0 ࡣඖᮇ toe ࡟࠾ࡅࡿᖹᆒ㐠ື[SC/s]࡛࠶ࡿࠋ
Ak

AREF  'A  A t k  t oe

(3.2)

nk

1n0  'n0  'n0 tk  toe2(3.3)

⾲ 3.1 LNAV ⾨ᫍ㌶㐨࣭᫬ィせ⣲M0

ᖹᆒ㏆ⅬゅSC'n0ᖹᆒ㐠ືࡢ⿵ṇ್

SC/se

㞳ᚰ⋡

A㌶㐨㛗༙ᚄࡢ᰿m:0

᪼஺Ⅼ㉥⤒

SC
SC-i0㌶㐨ഴᩳゅ

Z

㏆ᆅⅬᘬᩘ

SCWլ

᪼஺Ⅼ㉥⤒ࡢ᫬㛫ኚ໬⋡SC/sø㌶㐨ഴᩳゅࡢ᫬㛫ኚ໬⋡SC/sCuc⦋ᗘᘬᩘࡢవᘻㄪ࿴⿵ṇ㡯ࡢ᣺ᖜ

radCus⦋ᗘᘬᩘࡢṇᘻㄪ࿴⿵ṇ㡯ࡢ᣺ᖜradCrc㌶㐨༙ᚄࡢవᘻㄪ࿴⿵ṇ㡯ࡢ᣺ᖜ

mCrs㌶㐨༙ᚄࡢṇᘻㄪ࿴⿵ṇ㡯ࡢ᣺ᖜmCic㌶㐨ഴᩳゅࡢవᘻㄪ࿴⿵ṇ㡯ࡢ᣺ᖜ

rad

Cis

㌶㐨ഴᩳゅࡢṇᘻㄪ࿴⿵ṇ㡯ࡢ᣺ᖜradtoe࢚ࣇ࢙࣓ࣜࢫࡢඖᮇ

saf0⾨ᫍ᫬ィࣂ࢖࢔ࢫsaf1⾨ᫍ᫬ィࢻࣜࣇࢺs/saf2⾨ᫍ᫬ィࢻࣜࣇࢺ࣮ࣞࢺs/s2

toc⾨ᫍ᫬ィ᝟ሗࡢඖᮇsIOD⯟ἲ࣓ࢵࢭ࣮ࢪࡢⓎ⾜␒ྕ-SC: semi-circles (1 SC = 180 deg =Srad)⾲ 3.2 CNAV ⾨ᫍ㌶㐨せ⣲ࡢኚ᭦Ⅼ'$㌶㐨㛗༙ᚄࡢᇶ‽ AREF ࠿ࡽࡢᕪmк㌶㐨㛗༙ᚄࡢ᫬㛫ኚ໬⋡m/s'۪0ᖹᆒ㐠ື⿵ṇ್ࡢ᫬㛫ኚ໬⋡

SC/s2

LNAV ࡜ࡣ␗࡞ࡾ A࠾ࡼࡧ IOD ࡣᨺ㏦ࡉࢀ࡞࠸

4 CNAV ࡢホ౯
CNAV ࡢḟୡ௦ SBAS ࡟࠾ࡅࡿ฼⏝ྍ⬟ᛶホ౯࡜ࡋ࡚㸪⾨ᫍ㌶㐨࣭᫬ィ⢭ᗘࢆホ౯ࡍࡿࡇ࡜
࡛㸪CNAV ࢆ⿵ᙉࡍࡿࡇ࡜ࡢ࣓ࣜࢵࢺࢆホ౯ࡋ㸪
CNAV ࡢ฼⏝࡟క࠺ࢹ࣓ࣜࢵࢺࡢホ౯࡜ࡋ࡚㸪
L5 ᖏ I-Q ┦ࡢಙྕ㑅ᢥࡢၥ㢟࡟ࡘ࠸࡚㏙࡭ࡿࠋ─ 74 ─

電子航法研究所研究発表会（第16回平成28年６月）

ྛ᫬Ⅼࡢ⾨ᫍ㌶㐨ࡣඖᮇ toe ࡀ᭱ࡶ㏆࠸⯟ἲ࣓ࢵࢭ࣮ࢪࢆ౑⏝ࡋ࡚ồࡵ࡚࠸ࡿࡓࡵ㸪ඖᮇ
toe ࢆ୰ᚰ࡜ࡋࡓ 2 ᫬㛫㛫㝸ࡢ⯟ἲ࣓ࢵࢭ࣮ࢪࡢษࡾ᭰࠼ࡀ㸪ᅗ୰࡟ㄗᕪࡀ୙㐃⥆࡞Ⅼ࡜ࡋ࡚⾲ࢀ࡚࠸ࡿࠋࡲࡓ㸪LNAV ࡛ࡣ 04:00㸪CNAV࡛ࡣ 03:30 ࡢඖᮇ௜㏆࡛⏕ࡌ࡚࠸ࡿㄗᕪࡢ୙㐃⥆Ⅼࡣ㸪ࡇࡢ᫬Ⅼ࡛▷࠸㛫㝸࡛⯟ἲ࣓ࢵࢭ࣮ࢪ
ࡢ᭦᪂ࡀ⾜ࢃࢀࡓࡓࡵ⏕ࡌ࡚࠸ࡿࠋ
ᅗ 4.2 ࠾ࡼࡧ⾲ 4.2 ࡢ PRN06 ⾨ᫍࡢ౛࠿ࡽ
ศ࠿ࡿࡼ࠺࡟㸪LNAV ࡜ CNAV ࡣ㛗ᮇⓗ࡟ࡣྠᵝࡢㄗᕪഴྥࢆᣢࡘࡶࡢࡢ㸪CNAV ࡣඖᮇࢆ୰ᚰ࡜ࡋࡓ๓ᚋ 1 ᫬㛫ࡢㄗᕪኚືࡀ LNAV ࡟ẚ࡭࡚ᑠࡉ࠸ࡇ࡜ࡀศ࠿ࡿࠋ

LNAV ࡜ CNAV ࡢྛ⾨ᫍ㌶㐨ࡢࣛࢪ࢔ࣝ᪉
ྥㄗᕪࢆᅗ 4.1 ࡟♧ࡍࠋࡲࡓ㸪ࡑࢀࡒࢀࡢ⾨
ᫍ㌶㐨ㄗᕪࡢ RMS㸦Root Mean Square㸧ࢆ⾲
4.2 ࡟♧ࡍࠋᅗ 4.1㸪⾲ 4.2 ࡟ࡼࡿ࡜㸪LNAV
࡜ CNAV ࡣ 1 ᪥ࡢ㛗᫬㛫ࡢ⠊ᅖ࡛ࡣ኱ࡁ࡞ᕪࡀぢࡽࢀ࡞࠸ࡇ࡜ࡀࢃ࠿ࡿࠋḟ࡟㸪LNAV ࡜ CNAV ࡢᕪࡢ୍౛࡜ࡋ࡚㸪ᅗ 4.1 ୰ࡢ GPS ࡢ 6 ␒⾨ᫍ㸦PRN06㸧࡟ࡘ࠸࡚㸪ࡑࡢ㌶㐨ࡢࣛࢪ࢔ࣝ᪉ྥㄗᕪࢆᅗ 4.2 ࡟♧ࡋ㸪RMS ㄗᕪࢆ⾲ 4.2 ࡟ྜࢃࡏ࡚♧ࡍࠋ࡞࠾㸪ᅗ୰⦪ࡢ୍Ⅼ㙐⥺࡛♧ࡍ᫬Ⅼࡣ㸪ࡑࢀࡒࢀ
LNAV ࡜ CNAV ࡢྛ⯟ἲ࣓ࢵࢭ࣮ࢪࡢඖᮇ toeࢆ⾲ࡋ࡚࠸ࡿࠋ─ 75 ─

ᅗ 4.1 ඲⾨ᫍࡢࣛࢪ࢔ࣝ᪉ྥㄗᕪࡢẚ㍑

Radial orbit errors m4.1 ⾨ᫍ㌶㐨࣭᫬ィ⢭ᗘホ౯ḟୡ௦ SBAS ࡟࠾࠸࡚ CNAV ࢆ⿵ᙉࡍࡿࡇ࡜࡟ࡼࡗ࡚ᚓࡽࢀࡿ࣓ࣜࢵࢺࢆ᫂ࡽ࠿࡟ࡍࡿࡇ
࡜ࢆ┠ⓗ࡜ࡋ࡚㸪CNAV ࡢ⾨ᫍ㌶㐨࣭᫬ィ⢭ᗘࢆホ౯ࡍࡿࠋල య ⓗ ࡟ ࡣ 㸪 IGS 㸦 International GNSSService㸧[9]ࡀᥦ౪ࡍࡿ⢭ᐦᬺ㸦IGS Final㸧࡜࿧ࡤࢀࡿ㸪⾲ 4.1 ࡟♧ࡍᵝ࡟㧗⢭ᗘ࡞⾨ᫍ㌶㐨࣭᫬ィ᝟ሗࢆࣜࣇ࢓ࣞࣥࢫ࡜ࡋ࡚㸪2015 ᖺ11 ᭶ 9 ᪥ 0:00 㹼 24 㸸 00 㸦 GPST 㸧 ࡟ ࠾ ࡅ ࡿCNAV ࡢ⾨ᫍ㌶㐨࣭᫬ィ⢭ᗘࢆホ౯ࡍࡿࠋホ౯࡟⏝࠸ࡿ⾨ᫍࡣ㸪GPS Block-IIRM ⾨ᫍ㸦7 ᶵ㸪
PRN: 05, 07, 12, 15, 17, 29, 31㸧࠾ࡼࡧ Block-IIF⾨ᫍ㸦10 ᶵ㸪PRN: 01, 03, 06, 08, 09, 24, 25, 26,27, 30㸧࡛࠶ࡿࠋࡇࢀࡽࡣ㸪CNAV ࢆ㔜␚ࡋ࡚
࠸ࡿ L2C ಙྕࡶࡋࡃࡣ L5 ಙྕࢆᨺ㏦ࡋ࡚࠸ࡿ
⾨࡛ᫍ࠶ࡾ㸪CNAV ࡣୖグࡢ⾨ᫍ࡟ࡘ࠸࡚ࡢࡳ
ᨺ㏦ࡉࢀࡿࠋ
ホ౯࡛ࡣ⾨ᫍ㌶㐨ㄗᕪࡢ࠺ࡕ᭱ࡶ ఩࡟ᙳ㡪ࡍࡿせ⣲࡜ࡋ࡚㸪㌶㐨ࡢࣛࢪ࢔ࣝ᪉ྥㄗᕪࢆホ౯ࡍࡿࠋࡲࡓ⾨ᫍ᫬ィ࡟ࡘ࠸࡚㸪⯟ἲ࣓ࢵࢭ࣮
ࢪ࡛⿵ṇࡋࡓ⾨ᫍ࡟ᦚ㍕ࡉࢀࡓཎᏊ᫬ィࡢ᫬้࡜ GPST ࡢᕪࢆ㸪ග㏿ࢆ஌ࡌ࡚㊥㞳ࡢḟඖ࡜ࡋ࡚ホ౯ࡍࡿࠋホ౯ࡢᵓᡂ࡜ࡋ࡚㸪➨ 4.1.1 㡯࡟࠾࠸࡚ᚑ᮶
◊✲[1][2]࡜ྠᵝ࡟㸪GPS ༢⊂ ఩࡛⏝࠸ࡿࡇ࡜ࢆ᝿ᐃࡋࡓ༢⣧࡞⾨ᫍ㌶㐨࣭᫬ィ⢭ᗘࡢホ౯ࢆ⾜࠸㸪➨ 4.1.2 㡯࡟࠾࠸࡚ḟୡ௦ SBAS ࡟࠾ࡅࡿ CNAV ⿵ᙉࡢຠᯝ࡟ࡘ࠸࡚ホ౯ࡍࡿࠋ4.1.1 ⾨ᫍ㌶㐨࣭᫬ィ⢭ᗘ
⾨ᫍ㌶㐨⢭ᗘホ౯D

ᅗ 4.2 ⾨ᫍ㌶㐨ㄗᕪࡢẚ㍑㸦PRN06㸧
⾲ 4.1 IGS ⢭ᐦᬺࡢ௙ᵝ⾨ᫍ㌶㐨⢭ᗘ

㹼2.5 cm⾨ᫍ㌶㐨᭦᪂࿘ᮇ

15 minRMS㸸㹼75 ps㸦Ҹ2.3 cm㸧

⾨ᫍ᫬ィ⢭ᗘ

SDev㸸㹼20 ps㸦Ҹ0.6 cm㸧

⾨ᫍ᫬ィ᭦᪂࿘ᮇ

30 s

⾲ 4.2 ⾨ᫍ㌶㐨࣭᫬ィㄗᕪ㸦RMS㸧
LNAV

CNAV

㌶㐨 m

᫬ィ m

㌶㐨 m

᫬ィ m

඲⾨ᫍ

0.155

0.534

0.148

0.534

PRN06

0.073

0.129

0.071

0.087

電子航法研究所研究発表会（第16回平成28年６月）

E⾨ᫍ᫬ィ⢭ᗘホ౯LNAV ࡜ CNAV ࡢྛ⾨ᫍ᫬ィࡢㄗᕪ࡜㸪ࡑ
ࡢ RMS ࢆᅗ 4.3㸪⾲ 4.2 ࡟♧ࡍࠋᅗ 4.3㸪⾲
4.2 ࡟ࡼࡿ࡜㸪CNAV ࡜ LNAV ࡣ 1 ᪥ࡢ㛗᫬㛫ࡢ⠊ᅖ࡛ࡣ኱ࡁ࡞ᕪࡀぢࡽࢀ࡞࠸ࡇ࡜ࡀࢃ࠿ࡿࠋ
ࡋ࠿ࡋ࡞ࡀࡽ㸪ᅗ 4.3 ୰ࡢ Block-IIRM ⾨ᫍ㸪࠾ࡼࡧࢭࢩ࣒࢘ཎᏊ᫬ィࢆᦚ㍕ࡍࡿ୍㒊ࡢ
Block-IIF ⾨ᫍ㸦PRN: 08, 24㸧࡟ࡘ࠸࡚ࡣ㸪ᦚ㍕ࡉࢀ࡚࠸ࡿཎᏊ᫬ィࡢࣀ࢖ࢬࡀ኱ࡁࡃ㸪
LNAV ࡜ CNAV ࡢẚ㍑ࡀᅔ㞴࡛࠶ࡿࠋࡑࡇ࡛౛࡜ࡋ࡚㸪ᅗ 4.4 ࡟᫬ィࣀ࢖ࢬࡢᑠࡉ࠸ BlockIIF ⾨ᫍ㸦PRN: 06㸧ࡢ⾨ᫍ᫬ィㄗᕪࡢẚ㍑ࢆ♧ࡋ㸪⾲ 4.2 ࡟ࡑࡢ RMS ㄗᕪࢆྜࢃࡏ࡚♧ࡍࠋ࡞࠾㸪ᅗ 4.4 ࡟♧ࡍ⦪ࡢ୍Ⅼ㙐⥺ࡣ㸪ᅗ 4.2
࡜ྠᵝ࡟ྛ⯟ἲ࣓ࢵࢭ࣮ࢪࡢඖᮇ toe ࢆ⾲ࡍࠋ
PRN06 ⾨ᫍࡢ౛࠿ࡽศ࠿ࡿࡼ࠺࡟㸪LNAV ࡜CNAV ࡣ㛗ᮇⓗ࡟ࡣྠᵝࡢㄗᕪഴྥࢆᣢࡘࡶࡢ
ࡢ㸪CNAV ࡣඖᮇ toe ࢆ୰ᚰ࡜ࡋࡓ๓ᚋ 1 ᫬㛫ࡢㄗᕪኚືࡀᑠࡉ࠸ࡇ࡜ࡀศ࠿ࡿࠋ

4.1.2 SBAS ࡟࠾ࡅࡿ CNAV ࡢຠᯝᮏ 㡯 ࡛ ࡣ SBAS ࡟ ࠾ ࡅ ࡿ ฼ ⏝ ࡢ ほ Ⅼ ࠿ ࡽCNAV ࢆホ౯ࡍࡿࠋSBAS ࡛ࡣ⾨ᫍ㌶㐨࣭᫬ィㄗᕪࢆ⿵ṇࡍࡿᶵ⬟ࢆᣢࡘࡓࡵ㸪➨ 4.1.1 㡯࡛᫂ࡽ࠿࡜࡞ࡗࡓ㸪LNAV ࡜ CNAV ࡢㄗᕪࡢᕪࡣࡑࢀࡒࢀ⿵ṇࡉࢀ㸪ၥ㢟࡟࡞ࡽ࡞࠸ࠋၥ㢟࡟࡞ࡿࡢࡣ㸪SBAS ࡟ࡼࡿ⿵ṇࡢ᭦᪂㛫㝸࡟࠾ࡅࡿㄗᕪኚື㔞ࡢ኱ࡁࡉ࡛࠶ࡿࠋࡑࡇ࡛㸪ᅗ 4.1
࡜ᅗ 4.3 ࡟♧ࡍ⾨ᫍ㌶㐨࣭᫬ィㄗᕪ࡟ࡘ࠸࡚㸪
SBAS ࡟ࡼࡿ⿵ṇࡢ᭦᪂㛫㝸࡟࠾ࡅࡿㄗᕪኚື㔞ࢆホ౯ࡍࡿࠋලయⓗ࡟ࡣ㸪ḟୡ௦ SBAS ࡢICD ࢻࣛࣇࢺ∧[4]࡟ࡼࡿ࡜㸪⿵ṇ࣓ࢵࢭ࣮ࢪࡢ᭷ຠᮇ㝈ࡀ 240 ⛊࡛࠶ࡿࡇ࡜࠿ࡽ㸪⿵ṇࡢ᭦᪂࿘ᮇࢆ 240 ⛊࡜௬ᐃࡍࡿࠋࡑࡋ࡚ࡑࡢ㛫ࡢㄗᕪኚື㔞ࢆ㸪௵ពࡢ᫬้࡜ࡑࡢ 240 ⛊ᚋࡢ⾨ᫍ
㌶㐨࣭᫬ィㄗᕪࡢᕪ࠿ࡽồࡵ㸪ࡑࡢࣄࢫࢺࢢࣛ
࣒ࢆࡑࢀࡒࢀᅗ 4.5㸪ᅗ 4.6 ࡟♧ࡍࠋ
ᅗ 4.5㸪ᅗ 4.6 ࡟ࡼࡿ࡜㸪CNAV ࡢㄗᕪኚື㔞ࡣ LNAV ࡜ẚ㍑ࡋ࡚ᑠࡉ࠸ࡀ㸪ࡑࡢ኱㒊ศࡀ 1㹼2 [cm]௨ୗ࡛࠶ࡿࡇ࡜ࡀศ࠿ࡿࠋ
ࡇࢀࡽࡀḟୡ௦ SBAS ࡟࠾ࡅࡿ㌶㐨ࡢ఩⨨⿵ṇ ศ ゎ ⬟ 0.0625 [m] ࡜ ᫬ ィ ⿵ ṇ ศ ゎ ⬟0.03125[m]ࡼࡾࡶᑠࡉ࠸ࡇ࡜࠿ࡽ㸪CNAV ฼⏝࡟ࡼࡿ⾨ᫍ㌶㐨࣭᫬ィࡢㄗᕪኚືࡢᨵၿຠᯝࡣᑠࡉࡃ㸪ḟୡ௦ SBAS ࡟࠾࠸࡚㸪CNAV ฼⏝ࡢ࣓ࣜࢵࢺࡀ኱ࡁࡃ࡞࠸ࡇ࡜ࡀศ࠿ࡿࠋ

Clock errors mᅗ 4.3 ඲⾨ᫍࡢ᫬ィㄗᕪࡢẚ㍑

ᅗ 4.5 240 ⛊㛫ࡢ㌶㐨ㄗᕪኚືࡢࣄࢫࢺࢢ࣒ࣛ
ᅗ 4.4 ⾨ᫍ᫬ィㄗᕪࡢẚ㍑㸦PRN06㸧
௨ୖ࠿ࡽ㸪㏻ᖖࡢ༢⊂ ఩࡟࠾ࡅࡿ฼⏝ࢆ๓ᥦ࡜ࡋࡓホ౯࡟࠾࠸࡚㸪᪤Ꮡ◊✲࡜ྠᵝ࡟㸪
CNAV ࡣ ⾨ ᫍ ㌶ 㐨 ࣭ ᫬ ィ ㄗ ᕪ ࡢ ▷ ᮇ ኚ ື ࡀ
LNAV ࡜ẚ㍑ࡋ࡚ᑠࡉࡃ㸪㧗⢭ᗘ࡛࠶ࡿࡓࡵ᭷⏝࡛࠶ࡿࡇ࡜ࡀ᫂ࡽ࠿࡜࡞ࡗࡓࠋ
ᅗ 4.6 240 ⛊㛫ࡢ᫬ィㄗᕪኚືࡢࣄࢫࢺࢢ࣒ࣛ

─ 76 ─

電子航法研究所研究発表会（第16回平成28年６月）

4.2 CNAV ฼⏝ࡢᙳ㡪ホ౯CNAV ࢆ฼⏝ࡍࡿࡇ࡜࡛⏕ࡌࡿ㸪⾨ᫍ㌶㐨࣭᫬ィ⢭ᗘ௨እࡢᙳ㡪࡟ࡘ࠸࡚㏙࡭ࡿࠋ➨ 3.2 ⠇࡛ࡶ㏙࡭ࡿࡼ࠺࡟㸪CNAV ࡣ L5 ᖏ I┦ಙྕ㸦L5I5㸧࡛ᨺ㏦ࡉࢀ࡚࠸ࡿࡓࡵ㸪CNAVࢆ฼⏝ࡍࡿሙྜ࡟ࡣ L5I5 ಙྕࡢࢺࣛࢵ࢟ࣥࢢࡀᚲ㡲࡛࠶ࡾ㸪L5 ᖏࡢࡶ࠺୍ࡘࡢ ఩ಙྕ࡛࠶ࡿ Q ┦ಙྕ㸦L5Q5㸧ࢆ฼⏝ࡍࡿࡇ࡜ࡀ࡛ࡁ
࡞ࡃ࡞ࡿࠋࡋ࠿ࡋ࡞ࡀࡽ㸪L5Q5 ಙྕࡣ㸪ࢹ࣮ࢱࢆ㔜␚ࡋ࡞࠸ࣃ࢖ࣟࢵࢺಙྕ࡛࠶ࡿࡓࡵ㸪㧗⢭ᗘ࡞ ㊥⬟ຊࢆ᭷ࡋ࡚࠾ࡾ㸪 ఩⢭ᗘྥୖࡢࡓࡵ࡟✚ᴟⓗ࡞฼⏝ࡀᮃࡲࢀ࡚࠸ࡿಙྕ࡛࠶ࡿࠋ
ࡑࡇ࡛㸪CNAV ࢆ฼⏝ࡋ㸪᭦࡟ L5Q5 ಙྕࢆ฼⏝ࡋࡼ࠺࡜ࡍࡿࡓࡵ࡟ࡣ㸪ಙྕ㏣ᑿ࣮ࣝࣉࢆ᪂
ࡓ࡟㏣ຍࡍࡿᚲせࡀ࠶ࡿࠋࡋ࠿ࡋ࡞ࡀࡽ㸪ḟୡ௦ SBAS ࡣ DFMC ໬࡟ࡼࡗ࡚㸪ྠ᫬࡟ 30 ᶵࢆ㉸࠼ࡿ⾨ᫍ[10]ࡢ 2 ࿘Ἴಙྕࡢཷಙࡀᚲせ࡞ሙྜࡀ᝿ᐃࡉࢀࡿࠋࡑࡢࡼ࠺࡞୰࡛㸪L5Q5 ⏝ࡢಙྕ㏣ᑿ࣮ࣝࣉࢆ᭦࡟㏣ຍࡍࡿࡇ࡜ࡣ㸪ཷಙᶵ〇㐀ࢥࢫࢺࡢቑ኱ࢆᣍࡃ࡜⪃࠼ࡿࠋࡘࡲࡾ㸪ḟୡ௦ SBAS ࡟࠾࠸࡚ CNAV ࢆ฼⏝ࡍࡿࡇ࡜ࡣ㸪㧗⢭ᗘ࡞ L5Q5 ಙྕࡀ฼⏝࡛ࡁ࡞ࡃ࡞ࡿ࠿㸪ࡶࡋࡃࡣ L5Q5 ಙྕ⏝ࡢಙྕ㏣ᑿ
࣮ࣝࣉࢆ᪂ࡓ࡟㏣ຍࡍࡿᚲせࡀ࠶ࡾ㸪ཷಙᶵࢥࢫࢺࡢቑ኱ࢆᣍࡃ࡜࠸࠺ࢹ࣓ࣜࢵࢺࡀ࠶ࡿࠋ5 ⤖ゝᮏሗ࡛ࡣ㸪ḟୡ௦ SBAS ࡟࠾ࡅࡿ⿵ᙉ࡟㐺ࡍࡿ⯟ἲ࣓ࢵࢭ࣮ࢪࢆ᫂ࡽ࠿࡟ࡍࡿࡇ࡜ࢆ┠ⓗ࡜ࡋ࡚㸪LNAV ࡜ CNAV ࡢホ౯ࢆ⾜ࡗࡓࠋ⾨ᫍ㌶㐨࣭᫬ィ⢭ᗘホ౯ࡢ⤖ᯝ㸪CNAV ࡣ
LNAV ࡜ẚ㍑ࡋ࡚㧗⢭ᗘ࡛࠶ࡾ㸪༢⊂ ఩࡟࠾ࡅࡿ᭷⏝ᛶࡀ᫂ࡽ࠿࡜࡞ࡗࡓࠋࡋ࠿ࡋ࡞ࡀࡽ㸪
SBAS ࡛ࡣ⯟ἲ࣓ࢵࢭ࣮ࢪࡢㄗᕪࢆ⿵ṇࡍࡿࡓࡵ㸪⾨ᫍ㌶㐨࣭᫬ィࡢ⢭ᗘᕪࡀ୚࠼ࡿᙳ㡪ࡣᑠࡉࡃ㸪LNAV ࡜ CNAV ࡛᭷ព࡞ᕪࡀ⌧ࢀ࡞࠸ࡇ࡜ࡀ᫂ࡽ࠿࡟࡞ࡗࡓࠋࡲࡓ㸪CNAV ࡢ฼⏝࡟ࡼࡗ࡚⏕ࡌࡿᙳ㡪ࢆホ౯ࡋࡓ⤖ᯝ㸪CNAV ࢆ฼⏝ࡍࡿࡇ࡜࡛㸪㧗⢭ᗘ࡞ L5Q5 ಙྕࡀ฼⏝࡛ࡁ࡞ࡃ࡞ࡿ࠿㸪ࡶࡋࡃࡣ L5Q5 ಙྕ฼⏝ࡢࡓࡵ࡟
᭦࡟ಙྕ㏣ᑿ࣮ࣝࣉࡢ㏣ຍࡀᚲせ࡛࠶ࡿ࡜࠸࠺ࢹ࣓ࣜࢵࢺࡀ᫂ࡽ࠿࡟࡞ࡗࡓࠋ
௨ୖ࠿ࡽ㸪LNAV ࡜ CNAV ࡣ㸪ࡑࡢ⢭ᗘ࡟࠾࠸࡚᭷ព࡞ᕪࡀ⌧ࢀࡎ㸪ࡲࡓ㸪CNAV ࡢ฼⏝ࡣ㧗⢭ᗘ࡞ L5Q5 ಙྕࡢ฼⏝ࡀᅔ㞴࡟࡞ࡿ࡜࠸࠺ࢹ࣓ࣜࢵࢺࡀ࠶ࡿࡓࡵ㸪ḟୡ௦ SBAS ࡟࠾ࡅࡿ⿵ᙉ࡛ࡣ LNAV ࢆ฼⏝ࡍࡿࡇ࡜ࡀ㐺ษ࡛࠶ࡿ࡜⪃࠼ࡿࠋᮏ◊✲࡛ࡣ㸪௨ୖࡢ⤖ᯝࢆ SBAS IWG ࡟ᥦゝࡋ㸪௒ᚋࡣ LNAV ࢆ฼⏝ࡋࡓḟୡ௦ SBASࡢ㛤Ⓨࢆᐇ᪋ࡍࡿணᐃ࡛࠶ࡿࠋཧ⪃ᩥ⊩[1] P. Steigenberger, O. Montenbruck, and U.
Hessels, "Performance Evaluation of the EarlyCNAV Navigation Message", NAVIGATION,Vol. 62, No. 3, pp. 219-228, Fall 2015.
>@ H. Yin, Y.T. Morton, M. Carroll, and E.
Vinande, "Performance Analysis of L2 and L5
CNAV Broadcast Ephemeris for Orbit
Calculation", NAVIGATION, Vol. 62, No. 2,
pp. 121-130, Summer 2015. [3] International Standards and Recommended
Practices, Annex 10 to the Convention on Civil
Aviation: Aeronautical Telecommunications,Vol. I, 6th Ed., July 2006.
[4] SBAS IWG, “Draft IWG SBAS L5 Interface
Control Document (SBAS L5 ICD),” Issue 1,Rev. 1 Draft 036, March 2015.
[5] IS-GPS-200H, Interface Specification: Navstar
GPSSpace
Segment/Navigation
UserInterfaces.
[6] IS-GPS-705D, Interface Specification: Navstar
GPS Space Segment/User Segment L5Interfaces.
[7] “Global Positioning System Modernized Civil
Navigation (CNAV) Live-Sky Broadcast Test
Plan,” NAVCEN, 30 May 2013.
[8] J.H. Won, M. Anhileri, B. Eissfeller, A.
Schmitz-Peiffer, an J.J Floch, "Optimum Data
Rate and Signal Power Split for Next
Generation GNSS Architectures," Proc. ION
GNSS, pp. 2942-2955, September 2009.
[9] International GNSS Service( http://www.igs.org/ )[10]࢔ ࢪ ࢔ ࣭ ࢜ ࢭ ࢔ ࢽ ࢔ ᆅ ᇦ GNSS ࣡ ࣮ ࢡࢩࣙࢵࣉ࡜ඹྠᐇ㦂ᵓ᝿㸪➨ 5 ᅇ‽ኳ㡬⾨ᫍࢩࢫࢸ࣒࣮ࣘࢨ࣑࣮ࢸ࢕ࣥࢢ㸪2010㸬─ 77 ─