Appeal For help For Uttarakhand Flood Affected People

Please Contribute to Help the people of this region.
Donate to Prime Minister's National Relief Fund @ https://pmnrf.gov.in/

My prayers are with them.

OSPF Simple LAB using Juniper & Cisco (Area 0 only)

OSPF Simple Lab using Juniper & Cisco (Area 0 only)

config files:- 

http://www.4shared.com/office/S8_gaKsj/Cisco_Router.html

http://www.4shared.com/office/hm-6KNFc/JUNOS1.html

http://www.4shared.com/office/uev6sD_D/JUNOS2.html

Junos on GNS3 (easy setup with binary image)

 Junos on GNS3

here is the easy setup of junos olive on gns3 with binary image.

first download the image from below torrent :-

https://kickass.to/junos-binary-image-ready-for-qemu-gns3-t7523827.html

wait 7-8 mins and you will be prompt for username/password
 username :- root
 and no password just enter.

 
enjoy the junos for practice lab.

Thanks.

Dynamic Multipoint VPN (DMVPN)

Dynamic Multipoint VPN (DMVPN)

Config Files :- 

http://www.4shared.com/file/dFJnuAPU/R1_online.html

http://www.4shared.com/file/bzDBZ0Cw/R2_online.html

http://www.4shared.com/file/chQZ-7cj/R3_online.html

Group Encrypted Transport VPN (GETVPN)

Group Encrypted Transport VPN               

Config FIles :-
http://www.4shared.com/office/atsmJfzI/Key_Server_R4_config.html
http://www.4shared.com/office/W9jKEdpb/Member_R5_config.html
http://www.4shared.com/office/yeFdW0Mv/Member_R6_config.html

debug files :-
http://www.4shared.com/office/oLKe7lwi/debug_crypto_isakmp_on_keyserv.html
http://www.4shared.com/office/0WV6UQd1/debug_crypto_isakmp_on_member.html

Adaptive Optics Taking Twinkle out of the Star

Adaptive Optics

while searching on web i came across below picture.

that's the observatory but what so special about the picture. well that encourage me to find the answer. that's a laser guided observatory.it uses Adaptive optics to correct the distance object images.

while looking at a night sky we observe that stars are twinkling.star are twinkling because of the turbulance in the atmosphere.that's the big problem the astronomer faces while studying the distance galaxy,star,planets etc...while looking through the ground based telescope the images we see are blurry or distorted and cant able to study.

so how to solve this problem? one solution is to place the telescope where atmosphere turbulence is minimum or nearly zero.that's lead NASA to place the telescope out of the reach of the atmosphere.one of the extraordinary work of nasai s The HUBBLE Space Telescope(HST) located above 530 kms from the earth.images taken by the HST is extremely clear cause there is no atmosphere means no air for turbulence.

below is the some images taken by HST.

                                                Piller of Creation in star forming region.

                                                                    Ring Nebula

                                                                    Spiral Galaxy

but one problem with space base telescope is its very expensive.(includes space shuttle launch,deployment, maintenance, up gradation cost,not everyone can access the telescope)

so astronomers come across the idea of Adaptive Optics.

Adaptive optics measures the atmospheric distortions in the incoming light from a star or other object and sends electronic signals to a deformable mirror that can change its shape rapidly to correct for the distortions. In the system built for the 100-inch telescope, the light reflected from the telescope mirror is divided into several hundred smaller beams or areas. Looking at the beam of light from a star, the system sees hundreds of separate beams, some of which have been deviated because of atmospheric turbulence. The electronic circuits in the system compute the altered shape of a mirror surface that would realign the separate beams so that they are all going in the same direction. Then a signal is sent to the deformable mirror to change its shape in accordance with these electronic signals, resulting in an undistorted beam.

Thus images formed with the 100-inch telescope using adaptive optics are as sharp as those from NASA's Hubble Space Telescope. This is the most revolutionary technical development in astronomy since Galileo first used an astronomical telescope in 1609.

Below is the diagram of how adptive optics works.

YouTube link easy to understand how AO works.

but also one problem with AO is that there should be a enough light source (bright star) near the observe region.not every region of space have enough light source so,here we came above 1st picture at the starting of the blog.the laser guide observatory.

There are two main types of laser guide star system, known as sodium and Rayleigh beacon guide stars. Sodium beacons are created by using a laser specially tuned to 589.2nm to energize a layer of sodium atoms which are naturally present in the mesosphere at an altitude of around 90 kilometers. The sodium atoms then re-emit the laser light, producing a glowing artificial star. The same atomic transition of sodium is used to create bright yellow street lights in many cities. Rayleigh beacons rely on the scattering of light by the molecules which make up the lower atmosphere. In contrast to sodium beacons, Rayleigh beacons are a much simpler and less costly technology, but do not provide as good a wavefront reference as the artificial beacon is generated much lower in the atmosphere. The lasers are often pulsed, with measurement of the atmosphere being time-gated (taking place a few microseconds after the pulse has been launched so that scattered light at ground level is ignored and only light which has traveled for several microseconds high up into the atmosphere and back is actually detected

Below are without AO and with AO images.

Ephemeris Data (nasa jpl horizons)

Ephemeris Data

if you want to find exact position of solar system objects in the sky,one can use the best interface provided by nasa jpl horizon website ( http://ssd.jpl.nasa.gov/horizons.cgi ).

The Horizons On-Line Ephemeris System provides access to key solar system data and dynamic production of highly accurate ephemerides for solar system objects. This includes 611,000+ asteroids, 3200 comets, 176 natural satellites, all planets, the Sun, more than 60 select spacecraft, and dynamical points such as Earth-Sun L1, L2, L4, L5, and system barycenters. Users may conduct parameter searches of the comet/asteroid database, finding objects matching combinations of up to 42 different parameters. Users may define and integrate their own objects. Rise, transit and set may be identified to the nearest minute. When used with Sun and Moon sky-brightness data, observing windows can be identified. Close-approaches by asteroids and comets to the planets, Ceres, Pallas, and Vesta, can be rapidly identified along with the encounter uncertainties and impact probabilities. Orbital uncertainties can be computed for asteroids and comets.

More than 100 different observationaland physicalaspect quantities can be requested as a function of time for
both topocentric and geocentric observers, in one of 9 coordinate systems and 4 time scales (CT, TT, UT, Civil). 1500
Earth station locations are available, along with sites on other major bodies. Users may search for (or define)
topocentric site coordinates on any planet or natural satellite with a known rotational model. Spacecraft-based
observations are also supported. Output is suitable for observers, mission planners and other researchers, although this
determination is ultimately the user's responsibility. The underlying planet/satellite ephemerides and small-body
osculating elements are the same ones used at JPL for radar astronomy, mission planning and spacecraft navigation.
In addition to parameter searches, object data summaries, and close-approach tables, four types of
customizable ephemerides can be requested:
1) Observables (RA/DEC, Az/El, physical aspect, separation angles, uncertainty ellipses,etc.)
2) Osculating elements
3) Cartesian state vectors
4) SPK binaries (asteroids and comets only)
The first three are ASCII tables; output is returned to the user via browser, e-mail, FTP or Kermit protocols and
may be requested in a format suitable for spreadsheet import. SPK binary files allows user programs to reproduce the
integrated target state at any instant and may be used as plug-ins to existing visualization and mission-design software.

below is the sample data from Banglore Location on Target Body Venus.

i use mainly for Right Ascension and Declination data.