It's been quite a while.
The following is the latest iteration of the AESA Radar Calculator :
DOWNLOAD LINK. VER 3.
So what's new in the calculator ? :
1.Fixed the inconsistent unit in the calculation of detectability factors. Despite giving "reasonable" result, this actually may lead to erroneous calculation.
2.Improving the atmospheric factors, now the target altitude are used to calculate the elevation angle which then become input to the atmospheric absorption factor
3.Cutting down of the unnecessary pages, as apparently users are not really interested in additional tools such as RCS conversions (This one is partially integrated in the main sheet now) or tools to estimate limitation of radiated power based on cooling capacity.
New Features :
1.Custom Dwell time :
In previous edition, user are constrained in terms of selection of available dwell time for its respective radar. a Feature is added to allow custom dwell time to be inputted. So after user selects the dwell time in the respective drop down menu, if custom dwell time option is selected. User can then proceed to input the desired dwell time in the coloumn after the selection box.
2.Custom Detectability Factor
User can now choose to allow the sheet to estimate the detectability factor (SNR) Or manually input the value by him/herself. By default it selected to Yes.
Yeah so basically this displays the result of the calculations, since this calculator originally made for fighter aircraft radar, it is therefore using the airborne radar as parameters. The sheet's calculation have been adjusted that it allows comparison of radar works in different band (e.g L band vs X-band)
The range performance is presented in 3 categories based on the "level of confidence" Which is 50% (R50), 90%(R90) and Instrumented. The 50% probability of detection indicates the presence of a contact with 50% probability it's a "real" contact or ghost. Old NIIP Thikomirov site presented their radar data in this level of confidence. 90% Indicates higher threshold of detection/ high SNR, meaning that the target at that range is "90% a target" At this level of confidence the radar may begin process such as tracking or engagement/locking target with weapon systems. The Instrumented range is the range where the radar is "allowed" to "announce" detection. The value is about 20% of the maximum detection range. In this sheet it is assumed to be 20% of the R50, for increased "confidence" of a detected contact.
The "benchmark" fighter radars presented in the result sheet is based on open sources, APG-63V2, APG-79 and APG-83 however are estimated with ideal assumption (The platform is "matched" with the radar) Thus my overestimate the detection range value. All the range values are for 90% probability of detection. Given that there are no real disclosure on the assumption of detection probability for the radars i decided to make assumption that all the range values from the open source materials are for 50% probability of detection, thus needs to be "normalized" to 90%. To do that i first made estimate of SNR using the simple approximation provided in R.G Curry's "Radar Essentials" on SW1 target, which yield SNR value for respective detection probability (50% and 90%) The detection range can then be simply estimated by 4th Root using SNR as value. The result is estimate of the R90. eg Irbis-E with claimed detection range of 400 Km for 3 sqm target, in 90% it becomes 225 km.
This section is probably can be edited out if necessary. but yeah i feel it's needed
- Some appeal:
This calculator has been under development since 2015. It was at first to mainly satisfy my curiousity toward range estimation for a radar and what factor saffecting it. There is however another purpose, which basically to "escape" from at least some difficulties of my real life. Trying to make my 3D modeling hobby as a living, enjoyable but the income is not steady especially now. That my clients are apparently more concerned on surviving and therefore i received no income. Finding steady job is difficult here in Indonesia. So yeah. If you found this calculator helpful.. Maybe a little bit of donation to help me at least taking off the edge. it could be send through paypal at firstname.lastname@example.org.
Thank you very much for your attention