PSARS systems are built and designed robustly, with a view to be fixed at one site, and provide continuous surveillance capability from a height, which may not be otherwise possible.
Such systems are built to withstand testing UV and continuous exposure to sunlight, and/or very harsh cold climates. Based on where the aerostat would be deployed, it is critical for the manufacturer to plan the fabric design to withstand the conditions under continuous and sustained exposure to such conditions as the aerostat is expected to encounter during its deployment.
Since the PSARS system is meant for permanent of long term deployment, it is built with thicker and heavier material, generally requires a large team (Anywhere from 4-10 people) to wrap, unwrap and fill up. PSARS systems usually fly anywhere from about 2000 feet to as much as 30000 feet, depending upon application and mission. The Medium Altitude PSARS (MAPSARS) systems are usually heavier, built to last, work at altitudes from 2000 feet to upto 10000 feet, and carry heavier payloads, primarily used for surveillance and reconnaissance work. The higher altitude PSARS (HAPSARS) are usually very light, carry small payloads, and act as miniature satellites, working in near space region. HAPSARS can work with rechargeable solar batteries or cells, and usually are used for research work, high resolution photography and in some cases for communication. HAPSARS usually operate at altitudes upwards of 10000 feet, and can go upto 30000 feet or so. Some HAPSARS are designed to also have miniature positioning motors, which ensure that the system remains relatively at the same position for longer durations.
PSARS systems can stay afloat from about 7 days to about 6 months, without requiring helium/hydrogen refills. MAPSARS can be brought down, refilled, and sent back up in the air in a matter of a few hours.
Due to the nature of the work that the PSARS systems are supposed to carry out, they are designed with fabric that can last, and millions and perhaps billions of dollars are being spent by research companies all over the world, in developing fabric that is stronger, can last longer and have minimal leakage. However, the trade-off is always the weight of the fabric, which has a direct bearing on the capability of the full system to stay up in the air, and work at the designated height that the system is designed to work at. PSARS are known for heavy work, and can carry payloads anywhere from hundreds to even thousands of pounds, and therefore carry multiple payloads than can be used on demand. As an example, a large PSAR can carry different types of camera systems for day and night operation, RADARS, communication equipment and other equipment necessary for sustained surveillance activity.
Since PSAR deployment is generally fixed to one site for its lifetime, hence the site must be well prepared, guarded at all times, and appropriately protected. A typical PSAR deployment costs millions of dollars, and therefore loss of a PSAR means loss of critical capability.