ADM-Aeolus; Ground Station Options

Lidar Working Group, Wintergreen, 06/16/2009

ADM-Aeolus; Ground Station Options

Lars Peter Riishojgaard


Overview

• ADM/Aeolus data dissemination

– Data policy– Baseline ground segment– Possibly alternative ground stations


Data availability

• Data will be available in “real time” to operational meteorological users– This is in contrast to normal ESA data

dissemination policy

• WMO Global Telecommunication System used in principle for dissemination– GTS may or may not be most efficient

vehicle for transmission



Baseline ground segment

• Single receiving station at Svalbard– Full orbital dumps; 50 Mb of science data

per orbit– 110 s total visibility required for one orbit

• 30 s for antenna locking• 80 s for data dump• Any additional data may require additional time

(e.g. QRT or stored orbits)


NRT stream

– Near Real Time, defined as data (level 1B) having latency of 3 h or less for the end user

– NRT is targeted for global NWP and should in principle be available for all orbits

– Low ADM orbit height => blind orbits in spite of high latitude of Svalbard

– WMO requirement for global NWP is 1 h


QRT stream

• Quasi Real Time data targeted at regional NWP and other applications– Latency of 30 min or less– Assuming 20 (or 15) minutes total processing

time, the QRT stream will consist of the last 10 (or 15) minutes of the orbit dumped either at the beginning of the pass (“AEAP”) or at the end of the pass (“ALAP”)

– No Southern Hemisphere QRT data in Svalbard only scenario


QRT “AEAP” Scenario using Svalbard and Troll, assuming 15 (red+blue) or 20 minutes (blue) total processing time

(all figures courtesy of H. Nett, ESA/ESTEC)


QRT (II)

• QRT availability for Europe is guaranteed under combined Troll/Svalbard scenario

• QRT will not be available for North America under this scenario

• However, a receiving station at Troll now appears unlikely due to financial constraints

• On request from LPR, ESA has studied implications of adding either Wallops or Svalbard as additional ground receiving stations


ADM pass duration at Svalbard (red) and Fairbanks (green)


ADM pass duration (elevation > 2 deg) at Svalbard (red) and Wallops (blue)


ADM pass duration (elevation > 1 deg) at Svalbard (red) and Wallops (blue)


QRT “AEAP” Scenario using Svalbard and Wallops, assuming 15 (red+blue) or 20 minutes (blue) total processing time


QRT (III)

• Fairbanks adds relatively little to QRT scenario; sees basically the same orbits as Svalbard; adds robustness

• Due to near-perfect longitude, Wallops is a useful addition in spite of the low latitude

• Assuming 1 deg minimum elevation angle, Northern Hemishphere QRT will be available for all orbits under Svalbard/Wallops scenario


Potential NOAA involvement

• Advantages of Wallops/Svalbard scenario has been briefed to Kathy Kelly, Director of NESDIS/OSDPD– Positive initial reception

• OSDPD studying technical feasibility and financial implications

• Decision will be made at the NESDIS AA (Mary Kicza) level

– LWG statement of support?

Documents

ADM-Aeolus; Ground Station Options