Chriss A. Hammerschmidt, Robert T. Johnk, Savio Tran, and Mike Chang, “Continuous-Wave Propagation Channel-Sounding Measurement System — Testing, Verification, and Measurements,” Journal Article, June 2021

Channel sounders are used to measure channel characteristics for radio systems. There are several types of channel sounders used today: continuous-wave (CW), direct pulse, frequency domain using a vector network analyzer (VNA), correlation-based, and...

Chriss A. Hammerschmidt, Robert T. Johnk, and Savio Tran, “Calibration of Vector Network Analyzer for Measurements in Radio Frequency Propagation Channels,” Journal Article, June 2020

In situ measurements of radio frequency (RF) spectrum activity provide insight into the physics of radio frequency wave propagation and validate existing and new spectrum propagation models. Both of these parameters are essential to supporting and pr...

Jeanne Quimby et al., “Channel Sounder Measurement Verification: Conducted Tests,” Technical Report JR-20-549, April 2020

Channel modeling often provides a basis for the design and deployment of wireless technology. Engineers design systems to operate under certain expected channel conditions. Channel models are typically based on the statistics of a collection of many ...

Chriss A. Hammerschmidt and Robert T. Johnk, “Site-Specific Propagation Model Development,” Conference Paper, July 2019

Propagation models are used to inform scientists and engineers on how radio propagation through an environment will affect the radio signal received on the other end of the link. Many propagation models have been developed: some are curve-fitting mod...

We present path gain results at 3,500 MHz from a mobile channel measurement campaign that was carried out at the ITS Table Mountain Field Site. The purpose of this effort was to validate measurements obtained from a prototype sliding correlator chann...

Chriss A. Hammerschmidt, Robert T. Johnk, Paul M. McKenna, and Christopher R. Anderson, “Best Practices for Radio Propagation Measurements,” Technical Memorandum TM-19-535, November 2018

This report describes a set of best practices for the preparation and verification of radio propagation measurement systems. We discuss advantages and disadvantages of various channel sounders, the common components used in these systems, and measure...

Chriss A. Hammerschmidt and Robert T. Johnk, “Understanding the Impact of Terrain Databases on the Irregular Terrain Model,” Conference Paper, August 2017

This paper discusses a mobile propagation measurement in Los Angeles, CA and compares these measurements to the output from the Irregular Terrain Model (ITM). Propagation measurements are currently being used at the Institute for Telecommunication Sc...

Robert T. Johnk, Chriss A. Hammerschmidt, and Irena W. Stange, “A High-Performance CW Mobile Channel Sounder,” Conference Paper, August 2017

We describe an advanced mobile channel sounder system that has been under development by engineers at NTIA’s Institute for Telecommunication Sciences since 2010. We provide a description of the channel sounder and the key system components. We then h...

Chriss A. Hammerschmidt and Robert T. Johnk, “Extracting Clutter Metrics From Mobile Propagation Measurements in the 1755-1780 MHz Band,” Conference Paper, November 2016

This paper discusses mobile propagation measurement campaigns in San Diego, CA; Denver, CO; and Washington, D.C. These measurements were made to inform possible clutter models in the 1755-1780 MHz band. This band was recently auctioned and will now b...

Chriss A. Hammerschmidt, “Broadband Spectrum Survey in the Chicago, Illinois, Area,” Technical Report TR-14-502, April 2014

NTIA is responsible for managing the Federal Government’s use of the radio spectrum. In discharging this responsibility, NTIA uses the Radio Spectrum Measurement System to collect spectrum occupancy data for radio frequency assessments. This report s...

Chriss A. Hammerschmidt, “Broadband Spectrum Survey in the San Diego, California, Area,” Technical Report TR-14-498, November 2013

NTIA is responsible for managing the Federal Government’s use of the radio spectrum. In discharging this responsibility, NTIA uses the Radio Spectrum Measurement Sciences system to collect spectrum occupancy data for radio frequency assessments. This...

Chriss A. Hammerschmidt and Heather E. Ottke, “Spectrum occupancy results from several surveys,” Conference Paper, August 2013

This paper presents spectrum occupancy results from spectrum surveys conducted at three locations: Denver, CO; Table Mountain near Boulder, CO; and Point Loma, near San Diego, CA. Equipment setups are described along with the measurement algorithms u...

Chriss A. Hammerschmidt, Heather E. Ottke, and J. Randy Hoffman, “Broadband Spectrum Survey in the Denver Area,” Technical Report TR-13-496, August 2013

NTIA is responsible for managing the Federal Government’s use of the radio spectrum. In discharging this responsibility, NTIA uses the Radio Spectrum Measurement Sciences system to collect spectrum occupancy data for radio frequency assessments. This...

This report describes a free-field radio frequency (RF) measurement system that is currently being developed by engineers at the Institute for Telecommunication Sciences (NTIA/ITS). The objective is to provide estimates of the electrical properties o...

Robert T. Johnk, Chriss A. Hammerschmidt, Mark A. McFarland, and John J. Lemmon, “A Fast-Fading Mobile Channel Measurement System,” Conference Paper, August 2012

We describe a prototype propagation measurement system based on a combination of a spectrum analyzer and a vector signal analyzer. The system is designed to measure the characteristics of a narrowband mobile radio channel. We present results from a c...

Heather E. Ottke and Chriss A. Hammerschmidt, “Specialized Algorithms for Spectrum Surveys,” Conference Paper, August 2012

With increased demand in the radio spectrum, there have been multiple recent campaigns to quantify spectrum occupancy through measurements. These measurements can pose many challenges, one of which is created by impulsive noise. Below 500 MHz, impuls...

This report describes one of three free-field radio frequency (RF) measurement systems that are currently being developed by engineers at the Institute for Telecommunication Sciences (NTIA/ITS). The objective is to provide estimates of the electrical...