RF Drive Testing
Worldwide, juries are presented with a Call Detail Record (CDR) and cell phone location information as part of trial evidence. This information can sometimes exonerate or convict an accused. However, today, many verdicts are under review worldwide due to improper analysis of cellular CDRs. Specific verification techniques can help further confirm the accuracy and completeness of a CDR analysis. These survey techniques are called forensic radiofrequency verification, often referred to as drive testing.
What is Forensic Radio Frequency Verification (Drive Testing)?
Forensic radio frequency verification, commonly referred to as drive testing, is performed using specialized techniques, hardware, and software, to collect data on radio frequencies in an area of interest. Our location forensics experts use this data to determine the actual coverage area of a cell tower and its sectors. From there, they can create what's known as a propagation, or coverage map, for a specific tower. With that information, it is easier to pinpoint and determine if a cell tower has optimal service for a phone that may be reviewed as part of a legal investigation.
The Value of Radio Frequency Surveys (Drive Testing)
When we receive information concerning CDRs, we only know the tower and sector in which a phone was connected at a particular time. Radio frequency engineering data is not provided to an examiner. Using a drive test, the examiner can now see:
- Areas of the tower that are stronger than others
- Areas that have hot spots (or cell tower coverage that bleeds into others, creating spots of coverage that allow someone to connect to a cell tower farther away than expected)
- Areas that may not have coverage
- Other factors that may have affected signal coverage such as nearby wooded areas, bodies of water, large buildings, or topography
In other words, we can determine in much greater detail the likelihood of a cell phone connecting to a particular location. This data is used to validate claims concerning a person's location or challenge it if the radio frequency data collected through drive testing doesn't coincide with the mapping from call detail records alone.
The Envista Forensics Difference
Envista Forensics is one of only a handful of private companies that have access to the forensic software and hardware needed to perform forensic radio frequency verification surveys.
Our experts are certified in cell phone forensics, cellular networking, and global positioning system forensics. Collectively, our location forensics team has provided expert witness testimony dozens of times.