As Israeli security forces thwarted the latest attempt by terrorists to infiltrate Israel via tunnels from Gaza on Monday, The Jerusalem Post has learned that Israel may be underestimating the extent of tunnel penetration on its southern border.Steven Emerson, founder and executive director of the Washington-based Investigative Project on Terrorism, told the Post in an exclusive interview on Sunday that US intelligence officials believe that Israel is underestimating the number of tunnels.He said that according to a senior National Security Council official dealing with the Middle East, American satellites – equipped with special high resolution infrared detection technology – have preliminary findings of around 60 tunnels on the Israel-Gaza border.This number could actually be higher though because it does not include overhead satellite coverage of ground structures that are several stories in height and are impervious to infrared detection, Emerson said.This information seems to contradict Israeli estimates of remaining tunnels, Emerson said.The IDF told the Post on Monday that up until now 45 tunnels have been discovered, but when asked how many it estimated remain, it said that no information was available.Emerson said that the advanced American satellite, which was originally developed to deal with the Iranian theater, had been directed to orbit over Israel and send the data to specialized reconnaissance agencies operating under the aegis of the National Security Agency (NSA) for analysis. The infrared heat-seeking technology works by detecting changes in terrain density and the preliminary findings show that the tunnels are 1.5 m. by 1.2 m. and at least 46 m. in length.Emerson said that he is unaware if Israel requested such intelligence from the Americans or if it has yet been shared between the two nations – though he presumes that if it hadn’t it will be.Prime Minister Binyamin Netanyahu said on Sunday that the threat of the tunnels is not a new one and Israel is aware of them. “It is an operation with more risk, but it is vital. If these tunnels were not found, then the results would have been a lot worse,” Netanyahu said of the ground operations in Gaza.Emerson said that “according to American experts, there are only a couple of very specialized international corporations that manufacture tunnel-based equipment that detect unusual gaps in the density of hard rock being measured.”The technology also has commercial uses and assists in determining areas suitable for tunnels and mines.Emerson speculated that Israel did not purchase this equipment because of its high cost – and due to its belief that Israel can find and deal with the tunnels without it. He said that an ex-Israeli intelligence official who he spoke to came across as arrogant when speaking of the tunnel threat, and had a “we can deal with it,” attitude.“It is believed that the construction of the more advanced Palestinian tunnels began right after the 2012 cease-fire agreement, when Israel agreed to lift restrictions for humanitarian aid, including large quantities of steel and concrete,” he said, adding that the agreement to lift the blockade was overseen by Hillary Clinton. Egyptian tunnels are easier to build and are dug by using traditional excavation equipment and are meant mainly for commerce. These are easier to see, he said, adding that the ones crossing into Israel are for military purposes and “are of a totally different magnitude.”Emerson said that Hamas has learned from Hezbollah how to improve its use of tunnels. He also said that Hamas terrorists are probably not using any communication devices while inside the tunnels, making it harder to detect them.In addition, the tunnels are quite sophisticated, with water, sewage, and lighting allowing for month longs stays.Regarding Israel’s efforts at using conventional forces, such as tanks and troop carriers, Emerson said that these are easier targets for Hamas since they can gather intelligence on them from close up.Hamas has been very good at adapting and Israelis “need to think outside the box as they traditionally have and use their ability to think two steps ahead of their enemies,” Emerson said.Herb Keinon contributed to this report.