T&D employees tested the SPOT device during the summer of 2008 under three different canopy types at designated GPS test courses in western Montana and northern Idaho. The device was also tested in the Northern, Intermountain, Pacific Southwest, and Alaska Regions by field employees to determine such things as reliability, ease of use, transmission capabilities, and to gather users' overall impressions.

Four different tests were conducted at each site to determine how many messages were transmitted successfully.

• Check-in Tests—The check-in feature was tested at each survey marker on each test course. The check-in feature was initiated and the device was left at each marker for 20 minutes to give it time to send three messages. The face of the device was pointed toward the sky during these tests to simulate a person holding the device.
  
  
• HELP Tests—The HELP feature was initiated at one survey marker at each site and the device was left for 1 hour. The SPOT sends a HELP message every 5 minutes for 1 hour. To be considered successful, only one message needs to be successfully transmitted. The device was positioned horizontally, facing up.
  
  
• 24-Hour Tracking Tests (Horizontal)—The tracking feature was initiated at one survey marker at each site and left for 24 hours with the device positioned horizontally, facing up. The device sends a position message every 10 minutes for 24 hours.

The device's transmitter is on the face of the unit, making the faceup position optimal for transmissions. This test determines the percentage of messages that are transmitted and allows results to be compared to the same test using a transmitter in a vertical position. This test helps determine whether users should orient the device facing up in a pack or clipped vertically on their belt.

• 24-Hour Tracking Tests (Vertical)—The tracking feature was initiated at one survey marker at each site and the device was left for 24 hours, positioned vertically. The device sends a position message every 10 minutes for 24 hours.