The possibility to open a near-IR window at stratospheric altitude is crucial for a large variety of astronomical issues,
from cosmology to the star formation processes. Up to now, one of the main issue is the role of the OH and thermal sky
emission that are rising the sky background level when such observations are performed through ground based
telescopes. We present the results of our technological activity aimed at affording some critical aspects typical of balloon
flights. In particular, the obtained performances of prototype systems for rough and fine tracking will be illustrated. Both
these systems constitute a high precision device (≤ 1 arcsec) for pointing and tracking light telescopes on board
stratospheric balloons. We give the details concerning the optical and mechanical layout, as well as the detector and the
control system. We demonstrate how such devices, when used at the focal plane of enough large telescopes(2-4m, F/10),
may be capable to provide diffraction limited images in the near infrared bands. We have also developed a prototypal
single channel photometer NISBA (Near Infrared Sky Background at Arctic pole), working in the H band (1.65 μm), able
to evaluate, during a high-latitude balloon flight, how OH emission affects the sky background during the arctic night.
The laboratory tests and performance on sky are presented and analyzed.