classified  as  the  return  of  reflectivity  values  greater than or equal to 18.0 dBZ. A return to the "Clear Air Mode" must be manually selected at the UCP. Q44. Q45. Q46. Q47. Q48. Q49. Q50. Q51. Q52. Q53. Q54. Q55. REVIEW  QUESTIONS The antenna of the WSR-88D is part of what major system component? Which hydrometeor would provide higher dBZ values, hail or drizzle? The RDA is capable of reducing or eliminating what type(s) of radar problems? Which component of the WSR-88D contains algorithms  that  create  products? What is the difference between "base" products and  "derived"  products? Which component of the WSR-88D does the observer or forecaster use to request and obtain products? What  is  the  primary  input  device  when  operating a PUP workstation? Most Navy and Marine Corps stations with Principal User Processor (PUP) workstations are classified as being what type of WSR-88D system  user? WSR-88D narrowband links are maintained by what  mode  of  communication? Data  available  at  the  PUP  workstation  is recorded at which archive level? What  is  meant  by  the  term  "volumetric product"? Which  operational  mode  and  volume  coverage pattern should be selected when severe weather is present or expected? WSR-88D  PRODUCTS LEARNING   OBJECTIVES:   Identify   how WSR-88D products are acquired. Recognize the difference between base data and derived data. Identify the more commonly used base and derived products. Identify the uses and limitations of base and derived products. In this section, we will explain how products are acquired from the WSR-88D. Next, we discuss in detail the difference between base and derived data. We then examine some of the most commonly used products. Our operational overview of these products will  include  a  simple  description,  along  with  a discussion of the purpose, strengths, and limitations of each product. PRODUCT  ACQUISITION Products from the WSR-88D can be grouped into three   general   areas   of   application:   precipitation measurement,  storm  warning,  and  wind  profiling. These products become available to users in one of three ways. They are either specifically identified on a routine product set (RPS) list, solicited as a "one-time request" (OTR), or are automatically generated as an "alert"  condition  (alert-paired  product). Routine Product Set (RPS) An  RPS  list  provides  an  automated  way  of managing RPG workload. It allows associated users to identify and access routinely required products. Each PUP  site  tailors  its  own  list  according  to  mission requirements and modifies this list as needs change (via the UCP applications terminal). Each RPS list contains  up  to  20  products  catalogued  by  name  and distinguishing characteristics (i.e., elevation angle, range/resolution, etc.). Products found on the RPS list are generated every volume scan and then distributed to the appropriate user. One-time Request (OTR) Products that are not routinely needed are not usually placed on the RPS list. When such products are needed, associated users may obtain them via a one- time request. All one-time requests made by associated users will be honored by the RPG. Products not on the RPS list will be built on demand. With NAPUPs, however,  this  is  not  the  case.  Since  non-associatedusers cannot increase the RPG’s workload, new or unusual products are NOT built on demand for them. OTRs made by NAPUPs are only honored for pre-existing products stored in the RPG database. 2-33