Outline
GPS radiosonde is an upper-air sounding instrument
to measure various types of meteorological data;wind speed, wind direction, pressure, temperature andhumidity. Wind speed, wind direction and pressure
are calculated from the travel speed and altitude
obtained by GPS positioning techniques. Every 1
second measured data are transmitted to ground
receiving system via 400-406 MHz band.
Compact and commonly-used devices areaggressively adopted in iMS-100 to achieve
downsizing (just only 38 g including one battery) andits cost reduction. iMS-100 also serves for total
operation cost saving by using smaller balloon andreducing the gas amount depending on the target
height. Furthermore, the lightweight package greatly
enhances safety in the sounding operation even
without parachute when it accidently falls down on
land, especially.
Improved sensor boom achieves higher accuracy intemperature measurement. Also, newly developed
high response humidity sensor enables more accurate
humidity measurement even in low temperatureenvironment (below -40°C). In addition to theadvantages of cost and safety, the innovative
downsizing can minimize pendulum motions and heatcontamination from the sonde itself during launch,which improves the measurement performances interms of wind and temperature.

Features:
Compact & Light Weight Radiosonde● Much higher accurate measurements of temperature andhumidity, wind for the upper-air soundings● Light weight 38 g iMS-100 helps enhancing safe operation
especially when it falls down to the ground.
● Tiny iMS-100 effectively reducing overall operationalcosts (smaller balloon, fewer gas consumption) depends on
the target height● Downsized iMS-100 can contribute to reduceenvironmental burden through the entire life cycle(manufacturing, transportation, storage, and disposal)● One lithium battery enables more than 4 hours sounding
operation.
● High stability transmitter complying with ETSI (EN 302054 V1.1.1)● Easy preparation through wireless infrared communication(IrDA) between radiosonde and sonde checker unit before
launch
● Biomaterial package, which is environmental
friendly, is optionally available

Block Diagrams

Specifications (Uncertainty evaluation*1)
Temperature

Measurement range -95℃ to +60℃

Center freq.

404.5 MHz

Resolution

0.1℃

Tuning range *7

400 MHz ～ 406MHz

Uncertainty*2,30 to 16km : <0.4℃
Above 16km : <0.8℃

Band width< 15 kHz

Output power< 100 mW

Transmitter typeFM

Measurement range 0%RH to 100%RH

Standard

EN302 054 V1.1.1

Resolution

0.1%RH

Modulation type

Digital PCM

0 to 12km : <5%RH*4
12 to 17km : <5%RH

Baud rate

1,200 bps

Range

>300 km (with Yagi antenna)

Sampling

1 second

Voltage

3.0 VDC

Current< 200 mA

Battery type

Lithium battery ×１(CR-123)

Operating time

> 240 min.

Dimensions

55(W)×53(D)×131(H) mmWeight(Including a battery)

38 g (EPS)
40 g (Bio-based package)*9Unwinder

10m/ 15m/ 30 m

Balloon/parachute

Optional, please contact us.

Response time

Humidity*2,3

Uncertainty

Response time

Transmitter< 0.4 s（1,000 hPa, 5 m/s）

Modulation< 0.2 s (Absorbing, 1,000 hPa, 6 m/s , 0℃)< 14 s (Absorbing, 1,000 hPa, 6 m/s, -60℃)

Measurement range 1050.0 hPa to 3.0 hPa
Resolution

Pressure
Uncertainty*2,3,5

0.1 hPa
1km : <1.2hPa10km : <1.0hPa16km : <0.5hPa
24km : <0.2hPa32km : <0.1hPa

PowerSize & Weight *8

Measurement range -500 m to 40,000 m

Geopotential
HeightResolution

0.1 m

Uncertainty*2,3,5

1km : <11gpm
5km : <11gpm
10km : <11gpm
16km : <11gpm
20km : <11gpm
32km : <11gpm

Measurement range 0 °to 360 °WindDirection

Resolution

0.01 °

Uncertainty*3,5,6

0 to 16km: <1°with speed <10m/s<1° with speed >10m/s
Above 16km: <1°with speed <10m/s<1° with speed >10m/s

Measurement range 0 m/s to 200 m/s

WindSpeed

GPS Receiver

Resolution

0.01 m/s

Uncertainty*3,5,6

0 to 16km : <0.15m/s
Above 16km : <0.15m/s

Frequency

1574.25 MHz ±1MHz L1-C/A code

Number of channels

24 channels

AccompanyingitemsNote*1) The uncertainty values are calculated by the latest (April, 2016) JMA-GRUANevaluation*2) Expressed with coverage factor, k=2, unless otherwise explicitly specified.
*3) Including all significant sources of uncertainty described in WMO No.8(updated2017).
*4) Expect rapid humidity change around tropopause*5) Under optimal conditions of GPS reception : PDOP = 1*6) 1σ statistical uncertainty evaluated with GPS simulator by using sonde soundingscenario*7) Frequency can be changed every 100 kHz within the tuning range of 400 MHz and406 MHz. Applicable Radio Law/Regulations should be complied.
*8) Dimensions excluding antenna and sensor boom. Weight includes a battery, etc.
*9) Bio-based material package type is optionally available.

Outline View
Unit (mm)Positioning Technology DGPS (SBAS)
Pressure

1050.0 hPa to 3.0 hPa

Temperature-95℃ to +60℃

Humidity

0%RH to 100%RH

131Usage
Environment

5553

Cautions● For safe and correct usage, please read the "Operation Manual" prior to the use of the products.
● The specifications and appearances might be changed without prior notice, which please understand.
● The specifications shown in the catalog are of our standard products. We are pleased to customize it to meet customer's requirements. For the details, pleasecontact us.

● Please understand in advance that our company cannot assume the responsibility of any claims made by the third party about any monetary damages or any

loss of profits arising out from the use of our products.

● The color of the product photography on catalog might be different from that of actual product because of printing.

1-1, Toyosu 3-chome,Koto-ku, Tokyo 135-8115, Japan
Tel: +81-3-6204-8254 Fax: +81-3-6204-8888
http://www.meisei.jp/sonde/
Global Marketing Gr.
The specifications this catalog are current as of May 2020.
No. MSPA4-031

M2005