The AN/VDR-1() is being developed in response to a DA approved Qualitative Materiel Requirement (QMR) dated 3 March 1971. The radiac system must provide a means of conducting both dismounted and vehicular radiological surveys and for performing radiological monitoring of personnel and equipment. The system will replace both the IM-174/PD and IM-174A/PD radiacmeters and may replace the AN/PDR-27() radiac set. This system is not envisioned for use as an aerial survey meter, since the AN/ADR-6 is currently under development for that specific task. The system will be operated by the individual soldier. A driver should be able to operate it during vehicular radiological surveys. The system will be a TOE issue item to Army units. The equipment will not normally be pooled at higher echelons, except as maintenance floats. The basis of issue will be one system per platoon, company headquarters and subunit requiring a capability to detect low or high level contamination (e.g., medical section). The system will be operated in various climatic and weather conditions. The system will provide the commander with data concerning gamma dose rates in areas contaminated by fallout, neutron-induced gamma activity or radiological agents. This data will assist in the planning of tactical operations and medical monitoring of radiological casualties.