Author Archives: Marc Andre

Instrument error correction

The FAI logger allow instrument error correction to adjust for instrument error and drift of the sensors. The instrument error adjustment is configured using a separate config file (inst_cal.cfg) which is placed on the SD card. I’ve written many emails telling officials how to do this. I think it is time to post it…
I suggest to do the correction whenever possible. If you don’t use it, make sure the inst_cal.cfg file doesn’t exist on the loggers.

  1. Make sure the devices don’t have any inst_cal.cfg on the SD card and that the altitude is set to barometric. Probably best is to not use any SD card at all.
  2. Switch all devices on with the correct QNH. Let them heat up for 10-15 minutes
  3. Note the indicated altitude for all loggers.
  4. Use the Excel sheet to calculate the instrument error. If the reference altitude is known, it should be entered. If it is unknown, the median will be used. In that case the loggers are corrected among each other, but the absolute altitude might have some offset.
  5. Use the Excel sheet to create the inst_cal.cfg file. This file has the format XXX=123 with XXX being the 3-digit serial number and 123 being the altitude correction in decimeter. This value will be added to the measured altitude to get the indicated altitude. A single inst_cal.cfg file can contain the instrument error for all loggers used in the event.
  6. Copy the inst_cal.cfg to all SD cards or use BLM to copy it when initializing the SD card.
  7. Optional: Start all loggers again and check if the indicated altitude is within a small offset (Usually within 8m).

Important Note: The instrument error file on the logger is only used to adjust the indicated altitude. The altitude stored in the IGC file is not modified. Thus the same instrument error must be added during scoring. Do not use the header information in the IGC file, but use a separate database to prevent cheating possibility.

Remark: Pre 1.3.246 firmware release the file was named insterr.cfg. Based on feedback the file was renamed to inst_cal.cfg. Versions 1.3.246 and later automatically rename insterr.cfg to inst_cal.cfg if no inst_cal.cfg exists yet.

Download Excel sheet

New Firmware 1.2.193

Finally I found time to release the new firmware 1.2.193. This version mainly contains a work-around for the “leap-second-issue”. The GPS time is adjusted to the real earth rotation with leap-seconds (see Wikipedia). Because the leap-second information is only transferred in a slow interval (10 minutes), we could observe since July 2012 a jump back in time of the track when this information was received.
The new firmware works around this issue and ensures that the track has a correct and smooth time for the whole recording. Additional information is available upon request.
The new firmware can be downloaded in the Official’s section.

New BLM 2.1.189

Added new feature:
– Display and export to excel of the position where a declaration was made

Fixed issues:
– Export also points with no GPS fix to BFA scoring text file
– Fixed issue with regional setting dependency of BFA scoring text export

The software can be downloaded on the BLM page.

Guidance documents

With the Scoring WG we agreed to post two guidance documents for working with the CIA loggers. The documents describe how logger handling errors were dealt with during the Europeans 2011 and give recommendations for fail-over procedures.
The documents will be discussed in the CIA forum and during the next CIA conference with the Scoring WG and eventually be included in the COH.

Logger fail-over procedures
Electronic Mark Errors

New BLM 2.1.187 / updated SignatureLib

Added new BLM with the following new features:
– Added Swedish Grid SWEREF 99 TM. (no firmware upgrade of loggers needed)
– Added Drag&Drop for opening files.
Fixes:
– Fixed issue for signature validation when IGC file contains non-ASCII characters.

Also SignatureVerifier and SignatureLib have been updated to fix the bug mentioned above (for developers only).

The software and firmware can be downloaded in the Official’s section

Big success at the Europeans in Lleida

For the first time the loggers have been used in a continental championship. At the Europeans in Lleida 77 competitors flew 7 flights and 24 tasks. A total more than 500 tracks (>1000h) have been recorded. The loggers worked flawlessly. The off/on-problem is resolved. During the whole event no pilots GPS had to be downloaded and no data was lost! A big success and important milestone for the logger project.

A new screen might pop up: “New Flight?”

With the latest firmware upgrade of the logger a new question was introduced, that could show up at startup after entering QNH (See image).
Pilots, don’t get confused: The question is simple: Is it a new flight or not? If you start the logger before launch or at briefing and this question rises, the answer is yes. If you want to start the logger after the flight (e.g. at debriefing) to read your declarations, the answer is no.
When a new flight is started, the logger allows you to drop all markers again and also goal declarations disappear from the user interface. Be aware that in any way you cannot clear data from your tracks. The declarations/drops done so far will remain in the track, thus scoring will not be affected.

This functionality was introduced in order to allow to reset the logger in case something went wrong with clearing the so called declaration cache. Of course pilots are not allowed to use this functionality to redrop a marker that has already been dropped in flight. Doing this might be considered interfering with the logger.

New Firmware 1.2.180 and BLM 2.1.182

Added new firmware (and BLM) with the following new features:
– Depending on setting by the event director disallow multiple marker drops of the same number during flight.
– On startup in case old goal declarations or marker drops are found, ask the pilot if it is a new flight.
– If the logger is set to use GPS altitude, don’t ask QNH.
The software and firmware can be downloaded in the Official’s section