The Institute of Telecommunications Sciences (ITS) has developed three basic types of digital sampling probes. Two of the systems are suited for mobile measurements and the third one is most suited for wide–bandwidth, high–frequency measurements.

• Mobile Digital Probes

  The most recently developed mobile system digitizes and processes the received signal using a VME module. A second system digitizes the received signal with a digital oscilloscope and then processes the data using a conventional computer. While many of the earlier measurements were performed using the digital scope system, the trend is to move away from that system and to use the more power VME system.

• Wide Bandwidth, High–Frequency Digital Probe
  The techniques for data acquisition and processing in this system are similar to the digital scope system in that the signal is digitized at the IF by a digital oscilloscope and then processed on a conventional computer. While it is not as mobile as the other probes, it can still be used at walking speeds for distances up to a few hundred feet. This probe is particularly suited for high resolution requirements such as indoor measurements.