Possibilities For Situating A 1km2 Array

Stephen Fegan(UCLA)

Towards A Future Ground Based Gamma Ray Observatory October 20, 2005, Malibu, California

Possibilities For Situating A Square Kilometer Array Fegan, UCLA

Lessons From Simulations

Simulations show elevation effect not so large. Can compensate with:

Slightly larger dish Higher QE

Construction and operation costs grow dramatically with elevation above 3.5km

ALMA: O2 required for all work at 5kmConstruction with portable O2 tanksControl building has O2 plumbing

Consider here viable sites from 3-4km

Towards A Future Ground Based Gamma Ray Observatory October 20, 2005, Malibu, California

Possibilities For Situating A Square Kilometer Array Fegan, UCLA

Shuttle Radar Topography Mission

• NASA / NGA• STS-99, Feb 2000, 11 day on Endeavour• Surface elevation using radar interferometry • Between latitude of -56 and +60 (80% of world)• 1 arcsec horizontal accuracy (30m at equator)• 16m vertical accuracy• Data publicly available from JPL / USGS /

GLCF

Towards A Future Ground Based Gamma Ray Observatory October 20, 2005, Malibu, California

Possibilities For Situating A Square Kilometer Array Fegan, UCLA

SRTM Data Visualization

From NASA/JPL http://www2.jpl.nasa.gov/srtm/

Towards A Future Ground Based Gamma Ray Observatory October 20, 2005, Malibu, California

Possibilities For Situating A Square Kilometer Array Fegan, UCLA

SRTM Site Search

Search SRTM preliminary data set for Contiguous circular region With radius 720m (9×80m / 1.6km2) At elevation >2500m Flat to 100m Ignoring voids in data

Towards A Future Ground Based Gamma Ray Observatory October 20, 2005, Malibu, California

Possibilities For Situating A Square Kilometer Array Fegan, UCLA

Search Results

Elevation Key

>2500m >3000m >3500m >4000m >4500m >5000m

Towards A Future Ground Based Gamma Ray Observatory October 20, 2005, Malibu, California

Possibilities For Situating A Square Kilometer Array Fegan, UCLA

Search Results – Far West

Elevation Key

>2500m>3000m>3500m>4000m>4500m>5000m

Mexico

Guatemala

Hawaii

Towards A Future Ground Based Gamma Ray Observatory October 20, 2005, Malibu, California

Possibilities For Situating A Square Kilometer Array Fegan, UCLA

Search Results – Near West

Elevation Key

>2500m>3000m>3500m>4000m>4500m>5000m

Argentina

Bolivia

Peru

Ecuador

Colombia

Chile

Towards A Future Ground Based Gamma Ray Observatory October 20, 2005, Malibu, California

Possibilities For Situating A Square Kilometer Array Fegan, UCLA

Search Results – Near East

Elevation Key

>2500m>3000m>3500m>4000m>4500m>5000m

Nepal &China

Ethiopia

Kenya

Tanzania

Uganda

Congo

Iran

Towards A Future Ground Based Gamma Ray Observatory October 20, 2005, Malibu, California

Possibilities For Situating A Square Kilometer Array Fegan, UCLA

Search Results – Far East

Elevation Key

>2500m>3000m>3500m>4000m>4500m>5000m

China

Indonesia (Papua)

Towards A Future Ground Based Gamma Ray Observatory October 20, 2005, Malibu, California

Possibilities For Situating A Square Kilometer Array Fegan, UCLA

Hawaii

From Yahoo Travel http://travel.yahoo.com/ NASA Landsat / GLCF / http://landcover.org/

Towards A Future Ground Based Gamma Ray Observatory October 20, 2005, Malibu, California

Possibilities For Situating A Square Kilometer Array Fegan, UCLA

Hawaii – Mauna Loa (Active Volcano)Hawaii – Mauna Loa

Distance E-W [km]

Dis

tan

ce N

-S [

km]

NASA SRTM and Landsat data fromJPL : http://www2.jpl.nasa.gov/srtm/GLCF : http://landcover.org/

Towards A Future Ground Based Gamma Ray Observatory October 20, 2005, Malibu, California

Possibilities For Situating A Square Kilometer Array Fegan, UCLA

Mexico – Mexico City (Metro Region)Mexico – Mexico City

Distance E-W [km]

Dis

tan

ce N

-S [

km]

NASA SRTM and Landsat data fromJPL : http://www2.jpl.nasa.gov/srtm/GLCF : http://landcover.org/

Towards A Future Ground Based Gamma Ray Observatory October 20, 2005, Malibu, California

Possibilities For Situating A Square Kilometer Array Fegan, UCLA

Ecuador

Distance E-W [km]

Dis

tan

ce N

-S [

km]

NASA SRTM and Landsat data fromJPL : http://www2.jpl.nasa.gov/srtm/GLCF : http://landcover.org/