Input observation (METRo)

From Documentation

Contents 1 Description 1.1 Version and revision date 1.2 Default location 2 Contents 2.1 Mandatory fields 2.1.1 Header 2.1.2 Observations 3 Data source 3.1 Canada 4 Example

[edit] Description

This file contains the latest RWIS station observations (minimum 3 hours, optimally 12 hours).

[edit] Version and revision date

• Version: 1.0
• Revision date: Novembre 3rd 2004

[edit] Default location

No default location. Observation file must be specified as an argument to the command line.

[edit] Contents

The measurements taken by the RWIS station (air temperature, dew point, wind speed, etc.) as well as the date they were taken. This file must contain at least 1 valid observation, and each element in this observation must also be valid (you must have at least one sub-surface observation).

In the case that observations are not available from a site, pseudo-observations must be used. For example, some sites may not have a subsurface sensor. In this case, an estimate of the subsurface temperature may be used in the input observation file. If METRo is to be used in an iterative manner, the user can estimate the subsurface temperature for the initial run, and then use the output subsurface temperature from METRo's roadcast as input for the next run.

[edit] Mandatory fields

[edit] Header

Field description	Element name
Version number	version

[edit] Observations

Field description	Element name	Unit
Date and time of observation	observation-time	ISO 8601
Air temperature	at	Celsius
Dew point	td	Celsius
Presence of precipitation	pi	0: No -- 1: Yes
Wind speed	ws	km/h
Road condition	sc	SSI code
Road surface temperature	st	Celsius
Road subsurface temperature (40 cm)	sst	Celsius

Notes:

• Missing values are coded with the value: 9999
• All road condition values are considered wet except for 33 which is the SSI code for dry road.
• In the case of a bridge, METRo uses air temperature as the subsurface temperature.

[edit] Data source

[edit] Canada

Transport is mainly a provincial jurisdiction in Canada. Most of the RWIS stations providing observation to create a road forecast are the property of the Departement of Tranport of the province where it belongs.

Some cities also possess RWIS stations.

Please contact the corresponding authority if you want to get access to the observation.

[edit] Example

<?xml version="1.0"?>
<observation>
 <header>
  <filetype>rwis-observation</filetype>
  <version>1.0</version>
    <road-station>oaa</road-station>
  </header>
  <measure-list>
    <measure>
      <observation-time>2003-10-14T06:36Z</observation-time>
      <at>7.10</at>
      <td>5.50</td>
      <pi>0</pi>
      <ws>4</ws>
      <sc>3</sc>
      <st>9.80</st>
      <sst>17.00</sst>
      </measure>
   <measure>
      <observation-time>2003-10-14T06:56Z</observation-time>
      <at>8.20</at>
      <td>6.70</td>
      <pi>0</pi>
      <ws>0</ws>
      <sc>3</sc>
      <st>9.80</st>
      <sst>9999</sst>
   </measure>
       ...
  </measure-list>
</observation>

METRo I/O files

Station | Observation | Forecast | Roadcast | Configuration

METRo I/O specification

Schema | | Flowchart | Format | Date | Observation QA/QC | Road condition | Station type | Time zone | Layer type | Latitude and longitude

METRo I/O examples

Station | Observation | Forecast | Roadcast | Graphical display

This page is part of the documentation of the METRo software. Back to the table of content.