Automatic Weather Station Design for demanding environments. ICAWS-2017 Jorma Islander Vaisala Oyj

Transcription

1 Automatic Weather Station Design for demanding environments ICAWS-2017 Jorma Islander Vaisala Oyj

2 WMO Observations are key to our understanding of how the Earth system the atmosphere, oceans, freshwater bodies, land and the biosphere shapes our weather, climate and hydrology Page 2 [Automatic Weather Station Design for demanding environments

3 Background AWS network density in arctic region low Challenging environment Temperature range C Icing conditions Large wilderness areas No infrastructure roads, electricity, communication Wildlife Polar bears Page 3 Automatic Weather Station Design for demanding environments

4 Electronics design Wide temperature range Industrial temperature range only down to -40 C Some components only down to 0 C or -20 C >> careful component selection Design testing Testing in environmental chamber over temperature range Installed base feedback Low power consumption Page 4 Automatic Weather Station Design for demanding environments

5 Mechanical design Robust design Icing conditions Ice formation in structures >> heavy structures Strengh calculations High wind speeds Protection from wildlife Polar bears can destroy cabling Page 5 Automatic Weather Station Design for demanding environments

6 Sensors Wide temperature range Accuracy specification Typically defined down to -40 C Heated sensors should be used High power consumption Wind and precipitation most critical Page 6 Automatic Weather Station Design for demanding environments

7 Wind sensors Ultrasonic wind sensors Must be heated in winter conditions Easy to heat if power available Mechanical wind sensors Some heated models available Cup and wave heating challenging Non heated models Lightweight composite materials Special coating and color Page 7 [Name]

8 Telemetry Land based networks Only available in inhabited areas Cellular networks Limited coverage Geostationary satellites Inmarsat, Goes, Meteosat Not available in Polar areas Low earth orbit satellite systems Iridium, Argos Page 8 Automatic Weather Station Design for demanding environments

9 Telemetry Iridium satellite system Global coverage with 66 satellites Low power transmission Commercial system Low cost SBD data transfer Bi-directional communication Data delivered by or with TCP-IP data socket Page 9 Automatic Weather Station Design for demanding environments

10 Powering Mains power when available Sensors can be heated Solar power Sunshine not available during winter time Requires low power consumption and large batteries Wind turbine Vertical turbine better in high winds Fuel cell Requires heating, reliability Page 10 [Automatic Weather Station Design for demanding environments]

11 Powering Lead Acid Batteries Capacity reduces in low temperature Low cost Ni-Cd batteries Low Temperature operation High cost Transportation challenging New battery technology development Page 11 [Automatic Weather Station Design for demanding environments]

12 Software design Low power operation Heating control Measurement interval adjustment Data transmission control Diagnostics Built-in diagnostics Remote diagnostics Built in data quality control Page 12 [Automatic Weather Station Design for demanding environments]

13 Design Testing Environmental High / Low temperature Vibration / shock Sand and dust Ingress protection (IP) EMC characteristics Electrical safety Operational system testing Page 13 [Name]

14 Design Testing Low temperature testing 10W heating inside isolated enclosure Temperature measurements Outside enclosure Inside main enclosure Inside small enclosure Reference measurement Page 14 [Name]

15 Design Testing Low temperature testing Insulated enclosure 10 W heating Page 15 [Name]

16 Design Testing Heating power requirement test for isolated enclosure Page 16 [Name]

17 Installation Designed for easy installation Max 2 persons shall be needed No specific tools shall be needed Required tools shall be listed Precise installation instructions All components must be included Nearest hardware store can be far away Page 17 [Automatic Weather Station Design for demanding environments]

18 Maintenance Only annual maintenance Sensor calibration Replacing sensors System status information shall be available remotely Remote maintenance shall be possible Max 2 persons shall be needed Page 18 [Automatic Weather Station Design for demanding environments]

19 Conclusion Design testing is important to ensure perfect operation We should not forget that testing does not make quality! Testing is important part of the product development process For good and high quality products the product development, manufacturing and quality control processes are required Page 19 [Automatic Weather Station Design for demanding environments]

20 Thank you! Questions?