Olympus C-2100

Olympus C-2100 Ultra Zoom cameras are used for the CAM1 and CAM2 photographs.   The digital cameras have 10x optical zoom capability and a maximum resolution of 1600 x 1200 pixels.  A software program supplied by Air Resource Specialists Inc., controls camera functions like zoom, picture quality, exposure, and date/time stamping.  The program also controls the FTP function that sends the images to the web server.  Images are currently obtained every 30 minutes during daylight hours.  The daily start and stop times for imaging are adjusted according to seasonal requirements.

Gateway 700SE

Overall camera operation is controlled by a Gateway 700SE computer running the Microsoft Windows 2000 operating system.  The cameras are connected to the PC through RS-232 serial ports.  Images are acquired every 30 minutes and archived on the hard drive.  Image files are copied onto CD-R disks for eventual storage off-site.  Power to the cameras is supplied by a 24V AC power supply.  Power and signals are carried by conduit protected cable mounted on the WXII television tower.  The equipment is housed in a climate controlled room next to the tower and protected by several layers of uninterruptible power sources.

WXII Television Tower

Tower mounted equipment needs protection from hazards such as falling ice and lightning strikes.  Each camera is protected in a heated enclosure that is mounted to the tower.  Each enclosure is protected by a metal ice shield that is angled to divert falling ice from making direct impacts on the shield.  After a lightning related surge damaged both cameras in 2002, the wiring between cameras and the PC was upgraded to include communications using the RS-422/485 standard for greater signal isolation.

Optec NGN-2 Ambient Nephelometer

One of the major upgrades planned for Haze Cam during 2004 is the addition of visual range measurements.  To achieve that goal, an Optec NGN-2 ambient nephelometer has been purchased from Air Resource Specialists Inc.  The nephelometer will be installed on-site at Sauratown Mountain and will provide measurements of light scattering due to particles and aerosols in the atmosphere.  Due to the open-air design of the NGN-2, ambient temperature and relative humidity is taken into account, an important consideration due to the frequency of saturated fog conditions. In some areas, nephelometers are used to provide surrogate measurements for fine particle (PM2.5) monitoring. In this application, the nephelometer output (B-scat)  will be related to visual range measurements through a mathematical relationship. 

Field Measurements

Air quality and meteorological measurements displayed on Haze Cam are taken at a variety of monitoring sites in Forsyth County, North Carolina.  Ozone readings from the Union Cross site are obtained with a Thermo Environmental Systems 49C analyzer.   Fine particulates are measured by a Rupprecht & Patashnick 1400a/b TEOM sampler at the Hattie Avenue site.  Winds are measured by a Climatronics F460 system and the temperature/dew point readings come from a Yankee Environmental Systems MET-2010 unit.  A complete description of the Forsyth County air monitoring network is available.  A data file containing the air quality and meteorological readings is automatically sent by FTP to the web server on an hourly basis from our main office.  A script on the web server parses the data file for display.