India currently uses data from NASA satellites that pass twice a day over the region.
New Delhi:
Supreme Court ordered 24×7 data on stubble burning in Punjab and Haryana after farmers started timing the crop burning with the overpass of NASA satellites over the region, a problem first highlighted by NDTV two weeks ago.
The Supreme Court said the situation must be continuously monitored since farmers are burning their crops after 1:30 pm, the overpass time of NASA satellites over the subcontinent. This led to a severe undercount of crop burning data, especially in Punjab, while the Centre of Air Quality Management (CAQM) said there had been a 70 per cent reduction in numbers.
India currently uses data from NASA satellites that pass twice a day over Punjab and Haryana to monitor farm fires. The CAQM had said the Indian Space Research Organisation (ISRO) was asked in January to develop a system to study burnt areas to count farm fires.
Read here: Exclusive: Wary Of NASA Satellites, How Farmers In Punjab Time Crop-Burning, Scientist Explains
Farmers Avoiding NASA Satellites
Scientist Hiren Jethva at NASA Goddard Space Flight Centre, in a series of interviews with NDTV, was one of the first experts who highlighted the issue and how farmers are timing crop burning and said the number of “farm fires have not gone down”. “We use the afternoon satellite overpass time data from NASA Satellites like Suomi NPP and Aqua. They overpass the region around 1:30-2:00 pm but somehow they (farmers) have learnt that they can bypass the satellite overpass time and can burn the crop residue in the late afternoon. This is confirmed by the South Korean geostationary satellite that the majority of the crop burning happens after 2 pm once the NASA satellites overpass the region when there is no surveillance, but the fires cannot be hidden from geostationary satellites which take a picture of the region every five minutes.”
Today’s GEO-KOMSAT A2 satellite images visually convince of late afternoon burning acticitivities in NW India, avoiding NASA satellite surveillance around 1:30 PM IST @VishnuNDTV@CBhattacharji@parthaabosu@jksmith34@UrbanEmissions@avoiland@moesgoipic.twitter.com/BJsidjNqzy
— Hiren Jethva (@hjethva05) October 29, 2024
“Still, if we look at the geostationary images, there are many farm fires after 2 pm,” he told NDTV, adding that “the data from geostationary satellite is sensitive to the thermal signal produced by the fire. It lasts for at least four hours.”
Follow-up with Satellite Images
NDTV did a follow-up story on the issue, accessing exclusive satellite images, which appeared to confirm the inference made by Mr Jethva through his analysis.
Read here: Has There Been A Major Undercount Of Punjab Farm Fires? What Satellite Pics Show
NDTV accessed satellite images of a small area west of Amritsar, to understand the extent of farm fires on November 18 at 2:18 pm. It may look like an image of a warzone, but the smoke is not from the impact of bombs but from farmers burning their agriculture stubble. The red circles indicate the location of farm fires in a small area lying west of the Amritsar airport.
The satellite imagery experts consulted by NDTV, counted at least 26 independent farm fires in the north and west of Amritsar on November 18, shortly after NASA’s satellites with fire-detecting sensors had completed their overpass of the subcontinent.
The images were captured at 2:18 pm and farm fires were visible in the Maxar imagery. High res here
NASA Data
The yellow box next to Amristar is the location of the satellite images accessed by NDTV. The red dots are farm fires which have been detected by sensors from NASA World View, data from which is extensively used in India. The fire sensor data was taken at 2:18 pm on November 18, at the same time when other satellites, except NASA’s, passed over the region.
NASA Worldview data from November 18 at 2:18 pm after satellites overpass. High res Here
The images appear to confirm that there is a severe undercount of farm fires in Punjab which contribute significantly to the air pollution load this time of the year when farmers burn their agriculture stubble.
