名词解释：

SAR:Search and Rescue;

DASS：Distress Alerting Satellite System

NASA在5月25日公布了一个新的卫星系统，一旦有船只或者远足者失踪，这套系统确定其方位所需要的时间仅仅几秒钟。这项新技术要等到GPS的全部新卫星部署完毕之后才能投入使用。

GPS新卫星都装入DASS中继器，地球上每个角落都始终处在至少四颗卫星的视野之内。

克服了目前的卫星辅助搜救跟踪系统（SARSAT）的局限性。因为它无法告诉xx位置。

Satellite-Aided Search and Rescue

• More than 800,000 emergency beacons in use worldwide by the civil community – most mandated by regulatory bodies.
• It is expected to have more than 100,000 emergency beacons in use by U.S. military services.
• Since the first launch in 1982, current system has contributed to saving over 20,000 lives worldwide
• Satellite-aided SAR contributes to 300 persons rescued in US; 1,300 persons internationally.

NASA is responsible for Search and Rescue Research and Development.

Cospas-Sarsat Overview

Technology for satellite detection and location of aircraft and vessels in distress was developed by NASA in the 1970s. It evolved into an international cooperative effort with spacecraft hardware provided by Unites States, Canada, France, and Russia called Cospas-Sarsat System.

Cospas-Sarsat System currently has 38 participating countries, SAR payloads on 11 satellites, a worldwide network of 58 ground terminals, and supports search and rescue agencies worldwide.

Cospas-Sarsat System: Present Constellation

• Four US and Russian low-Earth orbit (LEO) satellites in polar orbit (LEOSAR)

Four US and international geostationary orbit (GEO) satellites (GEOSAR)

Distress Alerting Satellite System (DASS)

Distress Alerting Satellite System (DASS) is based on Global Positioning Systems (GPS). NASA is funding development for DASS with the goal to make it an operational part of International Cospas-Sarsat, which would significantly enhance its performance.

DASS Status:

• SARSAT system to be discontinued as SAR payloads are implemented on Galileo

6 Proof-of-Concept DASS payloads already on GPS

NASA Sponsored Cospas-Sarsat System Improvements

• Beacon Improvements: Prototype self-locating beacon designs, shared with industry; promoting the concept of beacon tracking
• Geostationary Satellites: Near instantaneous distress reception; Self-locating beacons also provide instant location
• Development of Micro Personal Locator Beacon (PLB); now a commercial product

Related Information

• NASA GSFC Search and Rescue Office
  
• National Search and Rescue Committee (NSARC)
  
• NOAA SARSAT Homepage
  

Cospas-Sarsat Homepage - International Satellite System for SAR