REFRACTIVE EFFECTS PREDICTION PROGRAMS

REVIEW QUESTIONS Q8. What is the purpose of the COVER program? Q9. What are the limitations of the SSP program? Q10. What is the major software advantage with the TESS-NC Transition as compared to the TESS (3)? Q11. Which government environmental software programs are provided with the TESS-NC? Q12. What is the purpose of the TESS-NC Unix-based workstation? REFRACTIVE EFFECTS PREDICTION PROGRAMS LEARNING OBJECTIVES: Identify the purpose of refractive effects prediction programs. Identify the refractive effects displays available with the Integrated Refractive Effects Prediction System (REPS) and the Advanced Refractive Environmental Prediction System (AREPS). Describe the major advantages of AREPS. Refractive effects prediction programs are designed to provide Aerographer’s Mates with the capability of assessing the refractive effects upon naval surveillance, communications, electronic warfare, and weapon-guidance systems. Either historical or real- time upper-air sounding data is used as input. INTEGRATED REFRACTIVE EFFECTS PREDICTION SYSTEM (IREPS) The first refractive assessment software program was the Integrated Refractive Effects Prediction System (IREPS) developed in the late 1970s. IREPS is designed for use over open ocean areas only. The program assumes the homogeneity of the atmosphere (single airmass) based on the input of a single upper-air sounding. Output options include various refractive effects products such as electromagnetic propagation conditions summaries (PCS), radar coverage display diagrams (COVER), path-loss versus range displays (LOSS), surface-search radar range tables (SSR), and Electronic Support Measures (ESM) radar intercept- range tables. The applications and limitations of these programs were covered with TESS (3) in the previous section. Although IREPS is resident software on TESS (3), it is no longer issued as a stand-alone program. In addition, most of the products produced by IREPS have been incorporated into GFMPL. ADVANCED REFRACTIVE ENVIRONMENTAL PREDICTION SYSTEM (AREPS) The most current refractive effects assessment program is the Advanced Refractive Environmental Prediction System (AREPS). AREPS computes basically the same refractive tactical decision aids as IREPS. However, AREPS uses a more advanced prediction model that produces more accurate data. The most significant advantage of AREPS is that it can produce refractive effects predictions over land using terrain data obtained from either the National Imagery and Mapping Agency (NIMA) or the users own sources. In addition, AREPS is able to evaluate range-dependent scenarios, and can also compute radar detection ranges for multiple bearings simultaneously. As of this writing, users must build their own electromagnetic riles as there is no electromagnetic data base provided with the program. Figure 2-2 is an example of an AREPS radar coverage diagram. The AREPS User’s Manual, SSC San Diego Technical Document 3028 provides a detailed description of the AREPS program. AREPS is designed to run using Windows 95 or Windows NT and is normally obtained as part of the GFMPL NT package. You can also down- load the AREPS program and the AREPS man- u a l f r o m t h e S P A W A R S w e b s i t e a t : http://sunspot.spawar.navy.mil. CD-ROM versions of AREPS are available from SPAWARS on a request- only basis. REVIEW QUESTIONS Q13. What is the purpose of refractive effects prediction programs? Q14. What is the most significant advantage of AREPS over IREPS? ELECTRO-OPTICAL TACTICAL DECISION AID (EOTDA) LEARNING OBJECTIVES: Define the term Electra-Optics. Identify the purpose of the Electra-Optical Decision Aid (EOTDA) program. Recognize the output options available from the EOTDA program. 2-12