Introduction

This Telemetry Attributes Transfer Standard (TMATS) Handbook is intended to supplement Chapter 9 of RCC IRIG 106 Telemetry Standards. Practical guidance for properly generating and using TMATS files is provided and examples of some of the more commonly used TMATS features are given. Since there may be multiple ways of describing these features in TMATS, the examples are intended to illustrate “best practices.” The overall purpose of this handbook is to improve the use of TMATS as a standard by presenting clear guidelines and thereby eliminating any misinterpretations that may exist.

The RCC IRIG 106 sets forth standards for various aspects of telemetry (TM) data transmission, recording, and processing. These standards constitute a guide for the orderly implementation of telemetry systems and provide the necessary criteria on which to base equipment design and modification. Their purpose is to ensure efficient spectrum utilization, interference-free operation, interoperability between ranges, and compatibility of range user equipment at the ranges.

The RCC held its first meeting in August 1951. In March 1952, the RCC Commanders established the Inter-Range Instrumentation Group (IRIG) to make recommendations for improvement of range instrumentation and conservation of the resources of the ranges. After a few meetings, the IRIG recognized the need to expand and specialize, and the IRIG Steering Committee was created to oversee several IRIG technical working groups. In 1971, the IRIG Steering Committee was disestablished, and the IRIG working groups became known as the RCC working groups. To this day, the RCC standards documents are still commonly referred to as “IRIG standards.”

The TMATS Standard was developed jointly by the RCC Telemetry Group Data Multiplex Committee and Data Reduction and Computer Group under a joint task begun in 1989. The standard was first published in 1993 as Chapter 9 of RCC IRIG 106. Since 1993, the Data Multiplex Committee has maintained this standard, with the primary goal of keeping it up to date with data types and features currently in use. Custom software tools were developed to work with the original “code name” TMATS format. In 2004, work began on a version of TMATS in the more widely used XML (eXtensible Markup Language) format. The initial version of a standard TMATS XML schema was published in 2007. Expressing TMATS in XML allows existing off-the-shelf XML software tools to be used to work with TMATS files. Both formats will be maintained for the foreseeable future.

The TMATS standard provides the common definition of the set of information needed to fully describe the data being transmitted from, or recorded on, an item under test. A TMATS file serves as the medium of exchange between the information source (usually an instrumentation organization) and the user (usually a test range). TMATS is not a data standard, but rather a description of existing data standards. For example:

a. The TMATS description of pulse code modulation (PCM) data in the P-Group and D-Group is based on the standards for PCM data in of RCC IRIG 106, Chapter 4.

b. The TMATS description of 1553 bus data in the P-Group and B-Group is based on the standards for 1553 bus data in Military Standard 1553 (MIL-STD-1553) and RCC IRIG 106, Chapter 8.

As these data standards are modified and standards for new data types are created, TMATS is also changed to reflect the improvements in the data standards.

TMATS was developed to improve the process of getting the information needed to describe the telemetry data for a particular test from its source to the system being used to process the data. See RCC IRIG 106, Appendix H, for a description of this process.

TMATS files are usually produced and read by software. Automating this process reduces the time needed to prepare a telemetry processing system to support a test and eliminates errors that inevitably result from entering this information manually.

The American Heritage Dictionary defines telemetry as:

“The transmission of data by radio or other means from remote sources to receiving stations for recording and analysis.”

Telemetry signals are formatted in what is commonly known as “pulse code modulation,” or PCM. Telemetry signals containing data of interest such as heading, air speed, altitude, voice, video, scientific information, and weather information, are transmitted from test items such as aircraft, weapons, ships, and ground vehicles.

Components of a basic telemetry system typically include:

1. Signal transducers.
2. Data acquisition system.
3. Transmitter.
4. Receiver.
5. Telemetry processing system.
6. Data display system.

With these systems, telemetry data can be transmitted over a radio link for retrieval at a ground station so that in-flight progress can be monitored.