Sub-meter Level Augmentation Service (SLAS)

This is the download site for QZSS archives about Sub-meter Level Augmentation Service (SLAS).

Sub-meter level augmentation signals (L1S) consists of information as follows.

・augmentation information of GPS L1-C/A and QZS L1-C/A

・Satellite Report for Disaster and Crisis Management (DC Report).

Note:Because of maintenance period of ground systems, etc., some data may be missing.

Refer to IS-QZSS-L1S.

Archived data (L1S) includes the L1S data for SLAS service transmitted from each QZSS satellite.

「Latency」 approximately 1 day

「Updates」 at 01:00 (QZSST)

「Sample Interval」 daily

「File Name」 as described in the table below

File Name (Archived data(L1S))
QNNN_YYYYMMDD.l1s
Code	Meaning
Q	Q=QZSS
NNN	Identification number of QZSS　satellite
YYYY	year
MM	month(double digit)
DD	day(double digit)

「Format」 as described in the table below

Repeated from “Week
Number” to “Spare”.
n:The number of repeats

「Parameter」 as described in the table below

Parameter	Description	Effective Range	Number of Bits	LSB	Units
PRN Number	The assignment of the PRN numbers by satellite categories (See IS-QZSS-L1S Table 3.2.1-1)	-	8	-	-
Week Number (at the broadcast time)	The starting point of the week number for QZSST shall be the same as that of the GPS time system (GPST)	0-4095	12	-	-
Time of Week (at the broadcast time)	The total seconds of a week at the beginning of the message.	0-604799	20	-	sec
L1S message	Each message are transmitted from QZSS satellite. (See IS-QZSS-L1S 4.1.)	-	250	-	-
Spare	Spare（fixed value: all 0）	-	6	-	-
: :	Repeated from “Week Number” to “Spare”. (n:The number of repeats)	-	288×n	-	-

STEP1 : Choose Data Period.

STEP2 : Choose needed data from Data List.

STEP3 : Download!

L1S Signal

L1S Signal

Results from 2025-04-18 to 2025-04-18

page 1 / 1

ALL	Data Type	Reference Time	Size(byte)	FileName

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