Without getting too chummy the U.S. and Iran have been trying to work out some rules for each other’s use of UAVs now operating over Iraq. Iranian UAVs have been seen flying over Iraq since late June, apparently with the approval of the Iraqi government (and quiet assent of the Americans, who already had F-16s and UAVs over Iraq). Between the U.S. and Iran there are often fifty or more UAV sorties over Iraq on some days. While Iraq is a big place, the UAVs from each country will often be seeking pictures of the same area at the same time. There have been no UAV collisions and few sightings by each other’s UAVs. Apparently the two nations have quietly agreed to leave each others UAVs to go about their business of supporting the Iraqi government in its fight against advancing ISIL Islamic terrorists. It’s unclear if there has been any sharing of information.
Relations towards each other’s UAVs have not always been so cozy. In 2009 two American F-16s followed a large (almost as large as a Predator) Iranian UAV inside Iraq for over an hour before finally shooting it down. Then in 2012 it was feared that Iran was going to return the favor as an American Predator UAV over international waters in the Persian Gulf spotted two Iranian Su-25 (a Russian ground attack aircraft like the U.S. A-10). The two Su-25s made several passes at the Predator and fired dozens of 30mm shells at it. None of the shells hit and the Su-25s flew back to Iranian air space, apparently to avoid an encounter with any American jet fighters on the way.
The Iranians have been developing UAVs since the 1980s. The largest of these is the Shahed 129, which is similar in size to the Israeli Hermes 450 (a 450 kg/992 pound aircraft with a 6.1 meter/20 foot wingspan). This is what the American F-16 pilot reported seeing and shooting down over Iraq in 2009. Iran did not report the Shahed 129 ready for service until 2012 and it has only been seen in or near Iran (as in over Iraq) since then. At least one has been spotted in Syria.
One of their most successful Iranian UAV designs was the Ababil, which was introduced in 2006. Nearly 400 Ababils have been produced so far. This is an 82 kg (183 pound) UAV with a 2.9 meter (9.5 foot) wing span, a payload of about 35 kg (77 pounds), a cruising speed of 290 kilometers an hour, and an endurance of 90 minutes for the first model. Current models (Ababil 3) can stay up for about four hours. The Ababil is known to operate as far as 249 kilometers from its ground controller. But it also has a guidance system that allows it to fly a pre-programmed route via GPS and then return to its ground controllers for a landing (which is by parachute). The Ababil can carry a variety of day and night still and video cameras. There are many inexpensive and very capable cameras available on the open market, as well as the equipment needed to transmit video and pictures back to the ground.
The Ababil has been seen in Sudan and Lebanon, where Iranian backed Hezbollah has received about a dozen of them. The Israelis feared that the low flying Ababils could come south, carrying a load of nerve gas or even just explosives. Using GPS guidance such a UAV could hit targets very accurately. That has never happened and Israel tweaked its air defense radars to detect small targets like Ababil.
Ababil should not come as a surprise. There's nothing exotic about UAV technology, at least for something like the Ababil. Iranian UAV development also got a boost from American UAVs received in the 1970s (Firebee target drones). In the last few years Hamas, in Gaza, obtained some Ababils, but these were not seen in the air until the July 2014 war between Hamas and Israel. Hamas claims to have used Ababil frequently to spy on Israel but there is no evidence for this (like recent photos taken of Israeli facilities).