Mars Helicopter Technology Demonstrator mentions on page 13/14 the sensors that Ingenuity carries, among them two cameras:
- Navigation (NAV) Camera. This is a global-shutter, nadir pointed grayscale 640 by 480 pixel sensor (Omnivision OV7251) mounted to a Sunny optics module. It has a field-of-view (FOV) of 133 deg (horizontal) by 100 deg (vertical) with an average Instantanous Field-of-view (IFOV) of 3.6 mRad/pixel, and is capable of acquiring images at 10 frames/sec. Visual features are extracted from the images and are tracked from frame to frame to provide a velocity estimate.
- Return-to-Earth (RTE) Camera. This is a rolling shutter, high-resolution 4208 by 3120 pixel sensor (Sony IMX 214) with a Bayer color filter array mated with an O-film optics module. This camera has a FOV of 47 deg (horizontal) by 47 deg (vertical) with an average IFOV of 0.26 mRad/pixel.
Both cameras are mounted on the helicopter Lower Sensor Assembly as shown below in Fig. 11. The NAV camera is pointed directly towards nadir, and the RTE camera is pointed approximately 22 deg below the horizon,...
Fig. 11 shows that the cameras are on the lowest part of the fuselage and the INGENUITY landing press kit mentions the helicopter has about 13 cm of clearance above the ground.
Can it be demonstrated that at least the 13 Megapixel colour camera, 13 cm above the ground and pointing 22 deg below the horizon, could take (more or less) detailed images of possible biosignatures ?
Wikipedia about the Mars 2020 mission:
The mission will seek signs of habitable conditions on Mars in the ancient past, and will also search for evidence - or biosignatures - of past microbial life, and water.
From the abstract of The mineral diversity of Jezero crater: Evidence for possible lacustrine carbonates on Mars we can deduce that a distinct unit along the inner margin of the crater is identified with strong carbonate signatures. It's been proposed that these "Marginal Carbonates" could be lacustrine in origin and could preserve macro- and microscopic biosignatures in microbialite rocks like stromatolites.
It's very likely that many of possible biosignatures along the margin of the crater will not be easy accessible by the rover so it would be beneficial if the helicopter could do some preinvestigation by taking more or less detailed images.