The Weather and Meteorology thread

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Bad weather hits 15 flights

TNN | Feb 8, 2019, 09:59 IST



A man shows hail on Thursday

A man shows hail on Thursday

JAIPUR: Heavy dust storm and hailstorm at many places in the state on Thursday evening came as a big cause of concern for the farmers eying on the sowing of Rabi crop. Many places in the eastern and northern Rajasthan witnessed high-velocity dust storm and lemon-sized hail storm in the evening. Door to the poor weather at New Delhi 15 Delhi-bond flights including 3 international and 12 domestic were diverted at the Jaipur airport. One of the domestic flights included a chartered in which Manohar Lal Khattar, chief minister of Haryana was travelling to Delhi from Jodhpur.


Attributing the climatic change to the active northerly winds the Jaipur met office said that similar conditions will prevail in the state for the next couple of days.


At Jaipur airport at 15 Delhi-bound flights got diverted on Thursday evening caused inconvenience to the passengers. “Three international flights including Dubai-Delhi, Sharjah-Delhi and Kabul-Delhi got diverted to our airport. Likewise, out of the 12 domestic flights there was one chartered plane in which Manohar Lal Khattar, the chief minister of Haryana was travelling. This flight took off from Jodhpur and was en-route to Delhi when it was diverted to Jaipur. All these flights departed to Delhi by 9.15 pm,” said Jaideep Singh Balhara, director, airport authority of india, Jaipur.


In its forecast thunderstorm and hail storm is likely to occur at many places in the eastern and northern parts of the state.


Bad weather hits 15 flights - Times of India
 

adsatinder

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2 killed, 10 missing as J&K gets heaviest snowfall this season
A couple was killed while their two children were rescued after an avalanche destroyed their home in Kokernag area of Anantnag district late on Thursday.
INDIA Updated: Feb 08, 2019 13:35 IST
Indo Asian News Service

Indo Asian News Service
Srinagar

Six policemen, two Fire and Emergency Services personnel and two prisoners went missing after another avalanche hit a police post near the Jawahar Tunnel on the Jammu-Srinagar Highway .(Waseem Andrabi / Hindustan Times)
Two persons were killed, while 10 others went missing and hundreds remained stranded on Friday due to the heaviest spell of snowfall in Jammu and Kashmir so far.
A couple was killed while their two children were rescued after an avalanche destroyed their home in Kokernag area of Anantnag district late on Thursday.
Six policemen, two Fire and Emergency Services personnel and two prisoners went missing after another avalanche hit a police post near the Jawahar Tunnel on the Jammu-Srinagar Highway .
Relief and rescue efforts on Friday have traced one of the missing, police said.
Multiple avalanches occurred at many other places in the Kashmir Valley, however, due to lack of communication and connectivity the extent of casualties or damage, if any, was not yet clear.
Authorities have shifted 78 families from avalanche-prone areas of Waltangoo Nar and Kund in Kulgam district to safer places.
Seven families were shifted to the Khag police station after an avalanche hit their village in central Badgam district.
Another, 20 families were shifted to safer places from Ganderbal.
Reports of seven to eight feet of fresh snowfall in the higher reaches and one to two feet in the plains in the past 24 hours indicate that this has been the heaviest snowfall of the season so far.
Hundreds of people were stranded in Jammu as the Jammu-Srinagar highway was shut for the third consecutive day after multiple avalanches and landslides hit various stretches of the 300-km long road.
Hundreds of Kashmiris were reported to be stranded in Delhi as flight operations remained disrupted since Wednesday and were completely closed at the Srinagar international airport on Thursday.
Morning flights could not operate to and from the Srinagar airport but operations were likely to resume shortly as the weather has improved significantly.
Electric power supply, water supply and road connectivity was also severely affected in the state.
Senior engineers of the electricity department said they supplied 850 megawatts of power to the valley on Thursday against the usual 1,200 megawatt requirement.
Despite these figures, most areas in the Valley and also some in Srinagar city remained without electric supply during the last 36 hours.
Water supply in areas where electricity is needed to operate drinking water plants has also remained adversely affected.
Roads in Srinagar and those connecting different district headquarters have remained partially closed since Thursday.
Restoration of all road links in Srinagar city and inter district road connectivity was expected to be completed by afternoon.
Availability of essential commodities including food items and petroleum products has been hit by continued closure of the strategic Janmu-Srinagar highway through which all essentials supplies are routed into the landlocked valley.
Mutton, poultry products and vegetables have vanished from markets in Srinagar city and other places.
Alarmed by depleting stocks of petroleum products, local administration has ordered rationing of petrol and diesel till the supply position improves.
This season’s snowfall has dispelled fears of water shortage in rivers, lakes, streams and springs during the coming summer months.
At the same time, the vagaries of nature have also taken their toll causing serious hardships to the people.
First Published: Feb 08, 2019 13:35 IST










2 killed, 10 missing as J&K gets heaviest snowfall this season
 

adsatinder

explorer
Hailstorm in Delhi-NCR, 18 flights diverted from IGI Airport
Western disturbances covered Delhi-NCR on Thursday and brought down temperature in the region.
INDIA Updated: Feb 07, 2019 20:15 IST
HT Correspondent

HT Correspondent
Hindustan Times, New Delhi
Delhi Rain,Hailstorm in Delhi NCR

A road covered with hailstones at Noida, Sector 82 on February 7.(Twitter/ANI Photo)
Several parts of Delhi-NCR witnessed moderate rainfall and thundershowers with strong winds on Thursday evening. Instances of hailstorm were reported from Noida, Faridabad and Gurgaon. The sudden change in wind pattern brought temperature in the region.
The hailstorm hit the Delhi-NCR region under the impact of western disturbances. According to Skymet Weather, the weather condition originated in the southwest of Delhi and is moving towards western Uttar Pradesh.
Airport officials said 14 domestic flights and four international ones were diverted to nearby cities between 6 pm and 7 pm. “In between 6 pm and 7 pm, nine flights were diverted to Jaipur airport. In the same time period, three flights each were diverted to Lucknow airport and Amritsar airport. Two flights were diverted to Varanasi and one flight to Indore in this one-hour period,” the official added, news agency PTI said.
According to another airport official, four out of the nine flights diverted to Jaipur were of Air India. “These four flights of Air India were heading to Delhi from Varanasi, Kathmandu, Dubai and Kabul,” he said.
Temperature in Delhi-NCR is likely to drop further during the night. Heavy rain intensity that was covered Delhi-NCR this evening is likely to return in the next two days.
Delhi skies had largely remained clear over the past two days with the maximum temperature rising to settle at 25 degrees Celsius, which was two notches above the season’s average. The minimum temperature was around 9 degrees Celsius.
However, rain and strong winds failed to improve the air quality in Delhi-NCR significantly. The air quality remained in the “very poor” category in the national capital on Thursday. News agency ANI quoted the System of Air Quality and Weather Forecasting And Research (SAFAR) as saying, “Air quality has not improved significantly as rainfall was not sufficient enough and wind speed was also moderate.”
Rain and hailstorm that lashed the parts of the national capital caught people in a surprise. Twitter is flooded with photos and videos of streets covered in hail. Moments after the shower, people began posting their reactions onto the micro-blogging site, making #DelhiRains trend on Twitter.

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Zafar [email protected]

https://twitter.com/zafarabbaszaidi/status/1093485148153143296

So we finally declare that all those who went to Mukteshwar or Kashmir to enjoy Snowfall have wasted their money. Delhi and NCR are having some fun. Look at these pictures from ....ahem ahem not Mussorie or Shimla but Noida. Chill !! #DelhiRains #Weather #Noida #ओले

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5:52 PM - Feb 7, 2019

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Shivendra [email protected]

https://twitter.com/shivendrasuman/status/1093486511050366976

ये तस्वीरें दिल्ली-NCR की हैं। शिमला, मसूरी का मजा ले रहे हैं दिल्ली वाले आज :)#DelhiRains

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First Published: Feb 07, 2019 18:17 IST




Hailstorm in Delhi-NCR, 18 flights diverted from IGI Airport
 

adsatinder

explorer
WEATHER UPDATE
Video 11 to 17 Feb 2019

Ok guys,
another huge WD is approaching,

As days zero in we will have to see if it is going to be bigger than the last one or same or a bit less.

But it will affect the whole of Himalayas right up to Arunachal Pradesh.

Specially those heading to Spit Valley right up to Kaza or maybe beyond,
don't push your luck, go till were you can go.
when you see that it is getting tough,
turn back, and get a Home Stay, and enjoy a full White Spiti.
Off course if you on a 4x4 with snow chains on all 4 tyres,
you would be able to go further. But then again, there is a limit to how much you can push onwards.
Take a decision well in time, it will be fun where ever you are.
If you do get stuck at Kaza or Pin Valley, remember you may be there for a few says, as lots of snow has already come from last snowstorm,
So don't panic. in 2 days or even a week you will be able to head back when it gets safer to move on the roads.
But never try your luck in these regions and snowfall.
Know when to turn back to a safer place, and you will still enjoy snowfall and all white around you.

So be prepared, and go well prepared.
lot of rain also will take place,
be careful of landslides.





RT
 

jammbuster

A Rebel, in pursuit of a memorable life ...
WEATHER UPDATE
Video 11 to 17 Feb 2019

Ok guys,
another huge WD is approaching,

As days zero in we will have to see if it is going to be bigger than the last one or same or a bit less.

But it will affect the whole of Himalayas right up to Arunachal Pradesh.

Specially those heading to Spit Valley right up to Kaza or maybe beyond,
don't push your luck, go till were you can go.
when you see that it is getting tough,
turn back, and get a Home Stay, and enjoy a full White Spiti.
Off course if you on a 4x4 with snow chains on all 4 tyres,
you would be able to go further. But then again, there is a limit to how much you can push onwards.
Take a decision well in time, it will be fun where ever you are.
If you do get stuck at Kaza or Pin Valley, remember you may be there for a few says, as lots of snow has already come from last snowstorm,
So don't panic. in 2 days or even a week you will be able to head back when it gets safer to move on the roads.
But never try your luck in these regions and snowfall.
Know when to turn back to a safer place, and you will still enjoy snowfall and all white around you.

So be prepared, and go well prepared.
lot of rain also will take place,
be careful of landslides.





RT
Nice info..but i hope BBC wale iss per apna claim na thok de

Sent from my ASUS_X007DA using Tapatalk
 

adsatinder

explorer
Nice info..but i hope BBC wale iss per apna claim na thok de

Sent from my ASUS_X007DA using Tapatalk
This is taken from BBC's Website only !

BBC Weather

Check weather prediction in animated map at middle of the page.

We assume only about the changes to happen and most are coming true most of the times.
IMD is also trying to predict but they are mostly 50% good than BBC's 70-80% perfection.
Local weather system can make changes and it is seen recently also.
For Himalayas, prediction is almost good more than 80%.
For Delhi or other warm areas, local weather is affecting the prediction and accuracy seen is almost 50-60%. only.
Big Picture looks almost good.
If you see place wise it is not perfect.
We need only Himalayan prediction.
WE know Delhi is un-predictbale in monsoon also.
But for other areas in Monsoon, accuweather is also good with its predictions.
Some other websites may show conflict also like Google's weather info.
Sources of info for these weather websites are common but calculation is little different.
Experts only can give better picture after they get feedback.
No expert can visit all places to see how prediction works.

I hope to see better Indian Predictions locally also with more Doppler Radars placement in future.
 

adsatinder

explorer
Doppler Radar


Doppler radar
From Wikipedia, the free encyclopedia


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Doppler effect.
A Doppler radar is a specialized radar that uses the Doppler effect to produce velocity data about objects at a distance. It does this by bouncing a microwave signal off a desired target and analyzing how the object's motion has altered the frequency of the returned signal. This variation gives direct and highly accurate measurements of the radial component of a target's velocity relative to the radar. Doppler radars are used in aviation, sounding satellites, Major League Baseball's StatCast system, meteorology, radar guns,[1] radiology and healthcare (fall detection[2] and risk assessment, nursing or clinic purpose[3]), and bistatic radar (surface-to-air missiles).
Partly because of its common use by television meteorologists in on-air weather reporting, the specific term "Doppler Radar" has erroneously become popularly synonymous with the type of radar used in meteorology. Most modern weather radars use the pulse-Doppler technique to examine the motion of precipitation, but it is only a part of the processing of their data. So, while these radars use a highly specialized form of Doppler radar, the term is much broader in its meaning and its applications.

Concept[edit]
Doppler effect[edit]

The emitted signal toward the car is reflected back with a variation of frequency that depend on the speed away/toward the radar (160 km/h). This is only a component of the real speed (170 km/h).
The Doppler effect (or Doppler shift), named after Austrian physicist Christian Doppler who proposed it in 1842, is the difference between the observed frequency and the emitted frequency of a wave for an observer moving relative to the source of the waves. It is commonly heard when a vehicle sounding a siren approaches, passes and recedes from an observer. The received frequency is higher (compared to the emitted frequency) during the approach, it is identical at the instant of passing by, and it is lower during the recession. This variation of frequency also depends on the direction the wave source is moving with respect to the observer; it is maximum when the source is moving directly toward or away from the observer and diminishes with increasing angle between the direction of motion and the direction of the waves, until when the source is moving at right angles to the observer, there is no shift.

Imagine a baseball pitcher throwing one ball every second to a catcher (a frequency of 1 ball per second). Assuming the balls travel at a constant velocity and the pitcher is stationary, the catcher catches one ball every second. However, if the pitcher is jogging towards the catcher, the catcher catches balls more frequently because the balls are less spaced out (the frequency increases). The inverse is true if the pitcher is moving away from the man. He catches balls less frequently because of the pitcher's backward motion (the frequency decreases). If the pitcher moves at an angle, but at the same speed, the frequency variation at which the receiver catches balls is less, as the distance between the two changes more slowly.

From the point of view of the pitcher, the frequency remains constant (whether he's throwing balls or transmitting microwaves). Since with electromagnetic radiation like microwaves frequency is inversely proportional to wavelength, the wavelength of the waves is also affected. Thus, the relative difference in velocity between a source and an observer is what gives rise to the doppler effect.[4]

Frequency variation[edit]
The formula for radar Doppler shift is the same as that for reflection of light by a moving mirror.[5] There is no need to invoke Einstein's theory of special relativity, because all observations are made in the same frame of reference.[6] The result derived with c as the speed of light and v as the target velocity gives the shifted frequency ({\displaystyle f_{r}}
f_r
) as a function of the original frequency ({\displaystyle f_{t}}
f_{t}
) :

{\displaystyle f_{r}=f_{t}\left({\frac {1+v/c}{1-v/c}}\right)}
f_{r}=f_{t}\left({\frac  {1+v/c}{1-v/c}}\right)

which simplifies to

{\displaystyle f_{r}=f_{t}\left({\frac {c+v}{c-v}}\right)}
{\displaystyle f_{r}=f_{t}\left({\frac {c+v}{c-v}}\right)}

The "beat frequency", (Doppler frequency) ({\displaystyle f_{d}}
f_{d}
), is thus:[7]

{\displaystyle f_{d}=f_{r}-f_{t}=2v{\frac {f_{t}}{(c-v)}}}
f_{d}=f_{r}-f_{t}=2v{\frac  {f_{t}}{(c-v)}}

Since for most practical applications of radar, {\displaystyle v\ll c}
v\ll c
, so {\displaystyle \left(c-v\right)\rightarrow c}
\left(c-v\right)\rightarrow c
. We can then write:

{\displaystyle f_{d}\approx 2v{\frac {f_{t}}{c}}}
f_{d}\approx 2v{\frac  {f_{t}}{c}}
Technology[edit]

U.S. Army soldier using a radar gun, an application of Doppler radar, to catch speeding violators.
There are four ways of producing the Doppler effect. Radars may be:

Doppler allows the use of narrow band receiver filters that reduce or eliminate signals from slow moving and stationary objects. This effectively eliminates false signals produced by trees, clouds, insects, birds, wind, and other environmental influences. Cheap hand held Doppler radar may produce erroneous measurements.

CW Doppler radar only provides a velocity output as the received signal from the target is compared in frequency with the original signal. Early Doppler radars included CW, but these quickly led to the development of frequency modulated continuous wave (FMCW) radar, which sweeps the transmitter frequency to encode and determine range.

With the advent of digital techniques, Pulse-Doppler radars (PD) became light enough for aircraft use, and Doppler processors for coherent pulse radars became more common. That provides Look-down/shoot-down capability. The advantage of combining Doppler processing with pulse radars is to provide accurate velocity information. This velocity is called range-rate. It describes the rate that a target moves toward or away from the radar. A target with no range-rate reflects a frequency near the transmitter frequency and cannot be detected. The classic zero doppler target is one which is on a heading that is tangential to the radar antenna beam. Basically, any target that is heading 90 degrees in relation to the antenna beam cannot be detected by its velocity (only by its conventional reflectivity).

Ultra-wideband waveforms have been investigated by the U.S. Army Research Laboratory (ARL) as a potential approach to Doppler processing due to its low average power, high resolution, and object-penetrating ability. While investigating the feasibility of whether UWB radar technology can incorporate Doppler processing to estimate the velocity of a moving target when the platform is stationary, a 2013 ARL report highlighted issues related to target range migration.[8]However, researchers have suggested that these issues can be alleviated if the correct matched filter is used.[9]

In military airborne applications, the Doppler effect has 2 main advantages. Firstly, the radar is more robust against counter-measure. Return signals from weather, terrain, and countermeasures like chaff are filtered out before detection, which reduces computer and operator loading in hostile environments. Secondly, against a low altitude target, filtering on the radial speed is a very effective way to eliminate the ground clutter that always has a null speed. Low-flying military plane with countermeasure alert for hostile radar track acquisition can turn perpendicular to the hostile radar to nullify its Doppler frequency, which usually breaks the lock and drives the radar off by hiding against the ground return which is much larger.

History[edit]

AN/APN-81 Doppler radar navigation system, mid-1950s

The US Weather Bureau's first experimental Doppler weather radarunit was obtained from the US Navy in the 1950s
Doppler radar tends to be lightweight because it eliminates heavy pulse hardware. The associated filtering removes stationary reflections while integrating signals over a longer time span, which improves range performance while reducing power. The military applied these advantages during the 1940s.

Continuous-broadcast, or FM, radar was developed during World War II for United States Navy aircraft, to support night combat operation. Most used the UHF spectrum and had a transmit Yagi antenna on the port wing and a receiver Yagi antenna on the starboard wing. This enabled bombers to fly an optimum speed when approaching ship targets, and let escort fighter aircraft train guns on enemy aircraft during night operation. These strategies were adapted to semi-active radar homing.

Modern Doppler systems are light enough for mobile ground surveillance associated with infantry and surface ships. These detect motion from vehicles and personnel for night and all weather combat operation. Modern police radar are a smaller, more portable version of these systems.[10][11]

Early Doppler radar sets relied on large analog filters to achieve acceptable performance. Analog filters, waveguide, and amplifiers pick up vibration like microphones, so bulky vibration damping is required. That extra weight imposed unacceptable kinematic performance limitations that restricted aircraft use to night operation, heavy weather, and heavy jamming environments until the 1970s.

Digital fast Fourier transform (FFT) filtering became practical when modern microprocessors became available during the 1970s. This was immediately connected to coherent pulsed radars, where velocity information was extracted. This proved useful in both weather and air traffic control radars. The velocity information provided another input to the software tracker, and improved computer tracking. Because of the low pulse repetition frequency (PRF) of most coherent pulsed radars, which maximizes the coverage in range, the amount of Doppler processing is limited. The Doppler processor can only process velocities up to ±1/2 the PRF of the radar. This is not a problem for weather radars. Velocity information for aircraft cannot be extracted directly from low-PRF radar because sampling restricts measurements to about 75 miles per hour.

Specialized radars quickly were developed when digital techniques became lightweight and more affordable. Pulse-Doppler radars combine all the benefits of long range and high velocity capability. Pulse-Doppler radars use a medium to high PRF (on the order of 3 to 30 kHz), which allows for the detection of either high-speed targets or high-resolution velocity measurements. Normally it is one or the other; a radar designed for detecting targets from zero to Mach 2 does not have a high resolution in speed, while a radar designed for high-resolution velocity measurements does not have a wide range of speeds. Weather radars are high-resolution velocity radars, while air defense radars have a large range of velocity detection, but the accuracy in velocity is in the tens of knots.

Antenna designs for the CW and FM-CW started out as separate transmit and receive antennas before the advent of affordable microwave designs. In the late 1960s, traffic radars began being produced which used a single antenna. This was made possible by the use of circular polarization and a multi-port waveguide section operating at X band. By the late 1970s this changed to linear polarization and the use of ferrite circulators at both X and K bands. PD radars operate at too high a PRF to use a transmit-receive gas filled switch, and most use solid-state devices to protect the receiver low-noise amplifier when the transmitter is fired.

Doppler navigation[edit]
Main article: Radar navigation

Doppler navigation system in the National Electronics Museum
Wind speed correction[edit]
Doppler radars were used as a navigation aid for aircraft and spacecraft. By directly measuring the movement of the ground with the radar, and then comparing this to the airspeed returned from the aircraft instruments, the wind speed could be accurately determined for the first time. This value was then used for highly accurate dead reckoning. One early example of such a system was the Green Satin radar used in the English Electric Canberra. This system sent a pulsed signal at a very low repetition rate so it could use a single antenna to transmit and receive. An oscillator held the reference frequency for comparison to the received signal. In practice, the initial "fix" was taken using a radio navigationsystem, normally Gee, and the Green Satin then provided accurate long-distance navigation beyond Gee's 350-mile range. Similar systems were used in a number of aircraft of the era,[12] and were combined with the main search radars of fighter designs by the 1960s.

Doppler navigation was in common commercial aviation use in the 1960s until it was largely superseded by inertial navigation systems. The equipment consisted of a transmitter/receiver unit, a processing unit and a gyro stabilised antenna platform. The antenna generated four beams and was rotated by a servo mechanism to align with the aircraft's track by equalising the Doppler shift from the left and right hand antennas. A synchro transmitted the platform angle to the flight deck, thus providing a measure of 'drift angle'. The ground speed was determined from the Doppler shift between the forward and aft facing beams. These were displayed on the flight deck on single instrument.[citation needed] Some aircraft had an additional 'Doppler Computer'. This was a mechanical device containing a steel ball rotated by a motor whose speed was controlled by the Doppler determined ground speed. The angle of this motor was controlled by the 'drift angle'. Two fixed wheels, one 'fore and aft' the other 'left to right' drove counters to output distance along track and across track difference. The aircraft's compass was integrated into the computer so that a desired track could be set between two waypoints on an over water great circle route. It may seem surprising to 21st. century readers, but it actually worked rather well and was great improvement over other 'dead reckoning' methods available at the time. It was generally backed up with position fixes from Loran, or as a last resort sextant and chronometer. It was possible to cross the Atlantic with an error of a couple of miles when in range of a couple of VORs or NDBs. Its major shortcoming in practice was the sea state, as a calm sea gave poor radar returns and hence unreliable Doppler measurements. But this was infrequent on the North Atlantic[citation needed]

Locus-based navigation[edit]
Location-based Doppler techniques were also used in the U.S. Navy's historical Transit satellite navigation system, with satellite transmitters and ground-based receivers, and are currently used in the civilian Argos system, which uses satellite receivers and ground-based transmitters. In these cases, the ground stations are either stationary or slow-moving, and the Doppler offset being measured is caused by the relative motion between the ground station and the fast-moving satellite. The combination of Doppler offset and reception time can be used to generate a locus of locations that would have the measured offset at that intersects the Earth's surface at that moment: by combining this with other loci from measurements at other times, the true location of the ground station can be determined accurately.[citation needed]





Doppler radar - Wikipedia
 

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5 years after ’13, state yet to get Doppler radars for weather forecast

TNN | Updated: Jun 19, 2018, 12:22 IST



DEHRADUN: Five years after the 2013 flash floods prompted the state government to announce setting up of Doppler radars, the state is still awaiting installation of the system that can make precise weather forecast related to extreme events by gathering real-time data.

A year after the 2013 deluge that caused widespread devastation, the Indian Meteorological Department (IMD) and the state government had announced that three radars would be installed to help predict extreme weather events.

The radars were to be installed under Integrated Himalayan Meteorology programme of Union Ministry of Earth Sciences. While many land surveys by technical teams have been conducted in the past couple of years, the installation of Doppler radars hangs in balance.

Bikram Singh, director of regional meteorological centre in Dehradun, told TOI that the ground work for installation of Doppler radars has been done and the three radars would be functional before 2020.

Singh added that the first Doppler radar is expected to be installed before the onset of next year’s monsoon and bids have been invited by IMD for the project.


The installation of Doppler radars was earlier delayed due to unavailability of suitable sites. In May last year, a team of IMD had visited Uttarakhand and zeroed in on three sites - Surkanda near Mussoorie, Mukteshwar in Nainital district and Pithoragarh - where Doppler radars would be installed.


Another factor for the delay was financial crunch. The state government wrote to IMD and the Union Ministry of Earth Sciences in 2015 seeking permission to procure Doppler radars under World Bank funded Uttarakhand Disaster Recovery Project (UDRP).


An official of the disaster management department said, “We sought permission from IMD to get Doppler radars under the UDRP as there was delay in IMD procuring them. However, IMD said that it had started the process.”


Meanwhile, the state government has also signed a Memorandum of Understanding (MoU) with the Karnataka State Natural Disaster Monitoring Centre (KSNDMC) to set up a dense weather forecasting network in Uttarakhand. Under the proposed network, automatic weather stations (AWS) and telemetric rain gauges would be installed in all 95 blocks in the state.


5 years after ’13, state yet to get Doppler radars for weather forecast - Times of India
 

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7 Radar Systems developed by DRDO for Indian Armed Forces
By
Harsh Bardhan
-
April 10, 2018
0
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In India, Electronics and Radar Development Establishment (LRDE) is the laboratory that comes under Defence Research & Development Organisation ( DRDO ) which is responsible for development of radars. This organisation has met success with various radar systems developed by it being inducted in Indian Armed Forces now in large numbers. This is seen as a step ahead for DRDO which aims to make India self-sufficient in various key military technology to reduce our import-dependency on foreign military hardware.

LRDE partners with Bharat Electronics Limited and private companies like Astra micro and Datapatterns for production of radars. Some of these radar systems are being highlighted below :
  1. INDRA (Indian Doppler Radar) : It is a series of 2D mobile surveillance radar for low level target detection. It features integrated Identification Friend-or-Foe System , Track while scan and full tracking capabilities for maneuvering targets. Besides being used by Indian Air Force and Indian Army it was also exported to Sri Lanka. Featuring advanced signal processing using MTD and CFAR Techniques it is claimed that it is easy to be transported.


2. RAJENDRA Radar : It is a multifunction electronically scanned phased array Radar which is the heart of Aakash Air Defence System. It is a passive electronically scanned array (PESA) radar and is used to guide Aakash missile to its target. Mounted on a two wheeled vehicle it fulfills multiple radar functions like surveillance, tracking and guidance. It can track 64 targets and engage 4 targets at a single time. Its range extends upto 80 kilometres and at an altitude of 18 km.

3. Central Acquisition Radar (3D-CAR) : It is a 3D S-Band Radar developed by DRDO for Indian Army and Indian Air Force. Army uses Rohini variant while Air Force uses Revathi variant. It can track targets upto a range more than 180 km and is capable of detecting low-altitude targets, and also supersonic aircraft flying at over Mach 3 speed. The radar features digital receiver, programmable signal processor providing high resolution, accuracy, response and information availability. The radar is packaged on two high mobility TATRA vehicles to meet operational and battlefield mobility requirements.



4. Swathi Weapon Locating Radar (WLR) : It is a C-Band pulse Doppler radar used for locating hostile artillery, mortars and rocket launchers and tracks friendly fire to locate the impact point of artillery fire to issue necessary corrections. It can track 7 targets at a single time and are helpful for Indian Army to locate Pakistani artillery positions across the LOC.
Pic Credit- Yashnews.com
5. Ashwini Radar : It is a 4D Low Level Transportable Radar and is developed to track hostile targets with foolproof accuracy. It can detect high-speed and maneuverable targets upto a range of 200 kilometres. It is an active phased array, and is easily transportable.
Pic Credit – Prokerala.com
6. Arudhra Radar : It is a Medium Power Radar (MPR) and is an active phased array multifunction 4D radar capable of automatic detection and tracking of aerial targets ranging from fighter aircrafts to slow moving targets. It features 2D Digital Beam-forming, Time synchronization of multiple receivers, Critical real-time software and firmware and DBF based active array calibration.

7. PJT-531 Battle Field Surveillance Radar : It is a man portable 2D short-range battlefield and perimeter surveillance radar. This radar has been a boon to Indian forces at LOC. It is used by Indian Army and BSF along with foreign customers like Indonesia and Sudan. It operates in J Band in 21 frequencies, and can detect crawling men, group of men, Armored Vehicles and Heavy Vehicles at varying distance.

7 Radar Systems developed by DRDO for Indian Armed Forces - DefenceLover
 

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Doppler radars provide precise information about thunderstorms, dust storms, hailstorms, rainfall and wind patterns. Photo: PTI


Doppler radars provide precise information about thunderstorms, dust storms, hailstorms, rainfall and wind patterns. Photo: PTI

IMD to add 30 Doppler radars in country
1 min read . Updated: 13 May 2018, 01:13 PM ISTPTI

With a radius of 250km, Doppler radars help in issuing nowcasts 2-3 hours prior to severe weather events

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IMDDoppler radarsIndia WhetherIndia Meteorological DepartmentMeT Departmentthunderstormsdust stormshailstormsrainfallwind patterns

New Delhi: The India Meteorological Department (IMD) will add 30 Doppler radars in the next two-three years across the country, of which several will be in the northeast, a senior IMD official said.
Doppler radars provide precise information about thunderstorms, dust storms, hailstorms, rainfall and wind patterns. With a radius of 250km, they help in issuing nowcasts 2-3 hours prior to severe weather events.
By the next year, Jammu and Kashmir will get four Doppler radars, Uttarakhand and Himachal Pradesh three each, additional director general (ADG) Devendra Pradhan said.
“We plan to add 30 Doppler radars in the next two-three years. The plan is also to have a total number 14 radars in the north east region, including the existing three that are already installed," Pradhan said.
Right now, the IMD is working on selecting locations in hilly states to install these radars, Pradhan added.
The hilly states of Uttarakhand, Himachal Pradesh and Jammu and Kashmir witness erratic patterns like thunderstorms and heavy rains and snowfall, so do the north eastern states. In 2013, a cloud burst that led to flash floods killed hundreds in Uttarakhand.
The first Doppler radar was installed in Chennai in 2002. Its need became more compelling after the 2005 Mumbai floods. There are currently 27 Doppler radars in the country.
The radar at Jaipur was non-operational during a freak thunderstorm that killed over 120 people in Uttar Pradesh and Rajasthan between 2-3 May.



IMD to add 30 Doppler radars in country
 
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